SBU54-056
Service Bulletin Details
Public Details for: SBU54-056
Freightliner custom chassis service bulletin for when troubleshooting powernet issues, use the bct-460dtna powernet assessment tool. As of may 29, 2018, the autometer is the only daimler-approved tool for troubleshooting vehicle powernet is
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Models from 2021
2021 FCCC MT45 |
2021 FCCC MT55 |
2021 FCCC S2 |
2021 FCCC S2RV |
2021 FCCC XBP |
2021 FCCC XBR |
2021 FCCC XBS |
2021 FCCC XCL |
2021 FCCC XCM |
2021 FCCC XCP |
2021 FCCC XCR |
2021 FCCC XCS |
Models from 2020
2020 FCCC MT45 |
2020 FCCC MT55 |
2020 FCCC S2 |
2020 FCCC S2G |
2020 FCCC S2RV |
2020 FCCC XBP |
2020 FCCC XBR |
2020 FCCC XBS |
2020 FCCC XCL |
2020 FCCC XCM |
2020 FCCC XCP |
2020 FCCC XCR |
2020 FCCC XCS |
Models from 2019
2019 FCCC MT45 |
2019 FCCC MT55 |
2019 FCCC S2 |
2019 FCCC S2G |
2019 FCCC S2RV |
2019 FCCC SL |
2019 FCCC XBP |
2019 FCCC XBR |
2019 FCCC XBS |
2019 FCCC XCL |
2019 FCCC XCM |
2019 FCCC XCP |
2019 FCCC XCR |
2019 FCCC XCS |
Models from 2018
2018 FCCC MT45 |
2018 FCCC MT55 |
2018 FCCC S2 |
2018 FCCC S2G |
2018 FCCC S2RV |
2018 FCCC XBP |
2018 FCCC XBR |
2018 FCCC XBS |
2018 FCCC XCL |
2018 FCCC XCM |
2018 FCCC XCP |
2018 FCCC XCR |
2018 FCCC XCS |
Models from 2017
2017 FCCC MT45 |
2017 FCCC MT55 |
2017 FCCC S2 |
2017 FCCC S2G |
2017 FCCC S2RV |
2017 FCCC XBP |
2017 FCCC XBR |
2017 FCCC XBS |
2017 FCCC XCL |
2017 FCCC XCM |
2017 FCCC XCP |
2017 FCCC XCR |
2017 FCCC XCS |
Models from 2016
2016 FCCC MT45 |
2016 FCCC MT55 |
2016 FCCC S2 |
2016 FCCC S2G |
2016 FCCC XBP |
2016 FCCC XBR |
2016 FCCC XBS |
2016 FCCC XCL |
2016 FCCC XCM |
2016 FCCC XCP |
2016 FCCC XCR |
2016 FCCC XCS |
Models from 2015
2015 FCCC MT45 |
2015 FCCC MT55 |
2015 FCCC S2G |
2015 FCCC XBP |
2015 FCCC XBR |
2015 FCCC XBS |
2015 FCCC XCL |
2015 FCCC XCM |
2015 FCCC XCP |
2015 FCCC XCR |
2015 FCCC XCS |
Models from 2014
2014 FCCC MT45 |
2014 FCCC MT55 |
2014 FCCC S2G |
2014 FCCC XBP |
2014 FCCC XBR |
2014 FCCC XBS |
2014 FCCC XCL |
2014 FCCC XCM |
2014 FCCC XCP |
2014 FCCC XCR |
2014 FCCC XCS |
Models from 2013
2013 FCCC MT45 |
2013 FCCC MT55 |
2013 FCCC S2G |
2013 FCCC XBP |
2013 FCCC XBR |
2013 FCCC XBS |
2013 FCCC XCL |
2013 FCCC XCM |
2013 FCCC XCP |
2013 FCCC XCR |
2013 FCCC XCS |
Models from 2012
2012 FCCC MT45 |
2012 FCCC MT55 |
2012 FCCC S2 |
2012 FCCC XBP |
2012 FCCC XBR |
2012 FCCC XBS |
2012 FCCC XCL |
2012 FCCC XCM |
2012 FCCC XCP |
2012 FCCC XCR |
2012 FCCC XCS |
Models from 2011
2011 FCCC MT45 |
2011 FCCC MT55 |
2011 FCCC S2 |
2011 FCCC XBP |
2011 FCCC XBR |
2011 FCCC XBS |
2011 FCCC XCL |
2011 FCCC XCM |
2011 FCCC XCP |
2011 FCCC XCR |
2011 FCCC XCS |
Models from 2010
2010 FCCC S2 |
2010 FCCC XBP |
2010 FCCC XCM |
2010 FCCC XCP |
Models from 2009
2009 FCCC XBP |
2009 FCCC XCM |
2009 FCCC XCP |
Models from 2008
2008 FCCC XBP |
2008 FCCC XCM |
2008 FCCC XCP |
Models from 2007
2007 FCCC XBP |
2007 FCCC XCM |
2007 FCCC XCP |
Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter > Recreational Vehicle > School Bus > Shuttle Bus 54-056 Freightliner Custom Chassis Service Bulletin > Walk-In Van > S2 IMPORTANT: When troubleshooting powernet issues, use the BCT-460DTNA PowerNet Assessment Tool. As of May 29, 2018, the AutoMeter® is the only Daimler-approved tool for troubleshooting vehicle powernet issues. Using the Powernet Assessment Worksheet For all battery, charging, or starting issues: 1. Print out the "Powernet Assessment Worksheet," found at the end of this bulletin. 2. Use the "Powernet Assessment Detail Section" to understand and master the worksheet. The detail section, starting on page 2, breaks the worksheet down step by step. 3. Perform each line of the worksheet in order, recording the initial value of each check before performing repairs. Repair issues as they are found, then recheck. Complete the entire worksheet even if the original issue seems to be resolved. 4. Once all the checks in the "Powernet Assessment Worksheet" have been completed, if a starting issue persists, use the "Troubleshooting the Starting System" section near the end of this bulletin. EPA10/EPA04 and EPA07 Vehicles Require Different Starter Path Voltage Drop Checks Two different starter path voltage drop checks are included in the worksheet: an EPA10/EPA04 Check 5, and an EPA07 Check 5. The alternator cables route through the starter on all vehicles except EPA07, so EPA07 vehicles have a different starter path voltage drop procedure. NOTE: EPA07 vehicles with jump start posts connected to the starter can be tested using the nonEPA07 (EPA10, EPA04) vehicle procedure by placing the carbon pile clamps on the jump posts instead of the alternator in check 5a and 5b. Using the jump posts will include them and their cables to the starter in the voltage drop check. + + − + + + − − − − − − − + 08/16/2013 f151181a Fig. 1, EPA04, and EPA10 and newer: the alternator routes through the starter. Use "Starter Path Check — EPA10, EPA04 Engines" for Check 5. Freightliner Custom Chassis Service Bulletin, 02/25/2019 + 08/16/2013 + f151182a Fig. 2, EPA07: the alternator does not route through the starter. Use "Starter Path Check — EPA07 Engines" for Check 5, unless the vehicle has jump posts. Page 1 54-056 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter Freightliner Custom Chassis Service Bulletin > Recreational Vehicle > School Bus > Shuttle Bus > Walk-In Van > S2 Powernet Worksheet Detail Section (Batteries, Path, Alternator) BATTERIES CHECK 1. Check battery pack voltage to determine state of charge. Charge pack to 100%. If unable, go to 3, "Break pack." DMM (Digital Multimeter): POS and NEG batt pack. Rec Value Accept Value 12.8V AGM 12.6V Flood Check 1 — Check battery pack voltage to determine state of charge. If equipped, set Load Disconnect Switch to "Off." With the DMM probes on the positive and negative posts of the battery pack, record the voltage. Due to differences in their design and operation, flooded cell and AGM batteries have different voltages at the same state of charge. Batteries should be fully charged before further testing. If batteries are not fully charged, they will draw current to recharge during testing, invalidating the troubleshooting test results. Fully charged batteries ensure reliable diagnosis. See Table 1 for voltage as an approximate indicator of state of charge (SoC) for AGM and flooded batteries. If the battery pack will not charge to 100% state of charge, there may be a shorted cell. Break the pack into individual batteries and test individually using an approved tester. Go to Check 3, Individual Battery Testing. After batteries have been tested individually, verify pack voltage once again. Flooded 12.6 12.4 12.3 12.1 12 11.8 AGM 12.8 12.6 12.4 12.2 12 11.8 SoC 100% 80% 60% 40% 20% 0% Table 1, Voltage to Approximate State of Charge (SoC) 2. Remove surface charge: HVAC blower, lights on, 5 min. Check 2 — Remove surface charge: HVAC blower, lights on, 5 min. Surface charge refers to a higher initial charge (volts), when discharging, in recently-charged batteries. This charge is a "shallow" charge, meaning that the charging-induced chemical reaction has mostly occurred at the surface of the lead plates, and has not equalized throughout the lead. Drawing current from the batteries before testing removes the surface charge, allowing for a better assessment of the "deep charge" state of the lead plates. After the surface charge is removed, the batteries need to be at least 80% SoC for further testing. See Table 1 for voltage as an approximate indicator of state of charge. 3. Break pack into individual batteries and test each with an approved battery tester. (Remove NEG cables first!) Replace batteries if instructed by the tester. Page 2 Batt 1: PASS or FAIL Batt 2: PASS or FAIL Batt 3: PASS or FAIL Freightliner Custom Chassis Service Bulletin, 02/25/2019 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter > Recreational Vehicle > School Bus > Shuttle Bus 54-056 Freightliner Custom Chassis Service Bulletin > Walk-In Van > S2 All batteries must pass the battery tester evaluation before troubleshooting continues. Batt 4: PASS or FAIL Check 3 - Individual Battery Testing IMPORTANT: Print and retain the battery test results once the battery test is completed. Batteries should only be tested individually. If the battery pack had to be charged, let the pack rest a minimum of 1 hour before testing the batteries. 3.1 Remove the negative cables of the batteries first, and secure the leads out of the way before touching the positive cables. Remove the battery cables and clean the terminal pads with a wire brush. The tester clamps will not make sufficient contact with dirty or corroded contact pads. 3.2 Connect the battery tester’s positive and negative clamps to the lead base terminal pads at the positive and negative studs. See Fig. 3. The threaded portion of the battery posts are not the right place to clip: the steel threads won’t make a good connection. The base of the post, on the lead, is the best place to clip. Taking a few extra seconds to make sure the tester, DMM, and carbon pile clips are well-connected can be the difference between a useful and a useless test. NOTE: If the lead base is too small to clamp to, only OEM-approved stud adapters should be used. The stud adapters must be screwed down tight against the cleaned lead base using a hand tool. The battery tester requires the CCA rating of the battery, which should be on the battery label. See Fig. 4. Refer to the battery tester instruction manual for complete testing instructions. 02/17/2017 02/17/2017 f151184 f151183 Fig. 3, The lead base of the post is the best place to clip. Fig. 4, 3.2 The label has the RC (reserve capacity) CCA (cold cranking amps) and SERIAL NO. (serial number). 3.3 If the battery fails, enter the battery serial number (see Fig. 4). PATH CHECK - CABLE VOLTAGE DROP TEST Alternator Path Check Carbon Pile: 4a. POS alternator, GND alternator. Load at alternator-rated amps. 4b. POS alternator, GND alternator. Load at alternator-rated amps. Freightliner Custom Chassis Service Bulletin, 02/25/2019 Rec Value DMM: POS alternator, POS batt pack + NEG alternator, NEG batt pack + Accept Value Total less than 0.7 V Page 3 54-056 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter Freightliner Custom Chassis Service Bulletin > Recreational Vehicle > School Bus > Shuttle Bus > Walk-In Van > S2 Combine the voltage from the positive and negative cable drop tests. = IMPORTANT: The batteries must be fully charged, and test good with the AutoMeter tool before the alternator test can be performed. Failure to test with charged batteries may reduce or delay full alternator output for approximately 15 minutes. Checks 4a and 4b – Alternator Path Check Setting up the Carbon Pile Clip the Carbon Pile positive clamp on the alternator positive post nut, and the negative clamp on the alternator body. NOTE: Ground may be on a post, not the body, for some Leece Neville alternators. Reading Voltage Drop with the DMM 4a - Alternator positive cable and connections voltage drop test 4a.1 Clip one lead of the DMM to the threaded portion of the positive post on the alternator and the other lead to the positive lead base of one of the batteries. See Fig. 5. 4a.2 The battery pack should now be assembled, cables connected, and nuts tightened 10 to 15 lbf·ft (13 to 20 N·m). The load disconnect switch should be set to "On." 4a.3 Load the system with the carbon pile to the alternator amperage rating for 5 to 10 seconds. Record the voltage drop shown on the DMM. The DMM should show voltage greater than 0 V. If the DMM displays 0.00 V when the load is applied, there is a connection problem; check the DMM’s connections and retest. NOTE: The alternator amp rating can be found on the alternator, and in PartsPro. See Fig. 6. 02/17/2017 f151187 Fig. 6, Rated amps can be found on the label. 02/17/2017 f151186 Fig. 5, Alternator Positive Cable Check 4b - Alternator negative cable and connections voltage drop test 4b.1 Clip one lead of the DMM to the alternator body and the other to the negative lead base of one of the batteries. NOTE: Ground may be on a post, not the body, for some Leece Neville alternators. Page 4 Freightliner Custom Chassis Service Bulletin, 02/25/2019 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter > Recreational Vehicle > School Bus > Shuttle Bus > Walk-In Van > S2 54-056 Freightliner Custom Chassis Service Bulletin 4b.2 Load the system with the carbon pile to the alternator amperage rating. Record the voltage drop shown on the DMM. Combine the voltage drop of the positive and negative cable voltage drop tests; the total should not exceed 0.7 V. If total voltage drop is greater than 0.7 V, go to Check 6, then test voltage drop again. If total drop is less than 0.7 V, go to the next check. Starter Path Check — EPA10, EPA04 Engines Carbon Pile: DMM: 5a. POS alternator, GND alternator. Load at 500 amps. POS starter, POS batt pack 5b. POS alternator, GND alternator. Load at 500 amps. NEG starter, NEG batt pack Combine the voltage from the positive and negative cable drop tests. Rec Value + + = Accept Value Total less than 0.7 V NOTE: EPA07 vehicles with jump start posts connected to the starter can be tested using this EPA10, EPA04 vehicle procedure by placing the carbon pile clamps on the jump posts instead of the alternator in 5a and 5b. Using the jump posts will include them and their cables to the starter in the drop test. NOTE: On EPA04 and EPA07 vehicles equipped with a load disconnect switch, expect up to a 0.5 V drop across the load disconnect switch. Starter Path Check – Checks 5a and 5b – EPA10, EPA04 Setting up the Carbon Pile Clip the carbon pile positive clamp on the alternator positive post and the negative clamp on the alternator body. See Fig. 7. NOTE: Ground may be on a post, not the body, for some Leece Neville alternators. Reading Voltage Drop with the DMM 5a - Starter positive cable and connections voltage drop test 5a.1 Clip the DMM to the threaded portion of the positive post on the starter and the positive lead base of one of the batteries. See Fig. 8. IMPORTANT: If the positive alternator cable is smaller than 2/0 AWG, use the "Starter Path Check EPA07" procedure instead. 5a.2 Load the system with the carbon pile at 500 amps. Record the voltage drop shown on the DMM. 5b - Starter negative cable and connections voltage drop test 5b.1 Clip the DMM to the threaded portion of the negative post on the starter and the negative lead base of one of the batteries. Freightliner Custom Chassis Service Bulletin, 02/25/2019 Page 5 54-056 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter Freightliner Custom Chassis Service Bulletin 06/24/2013 > Recreational Vehicle > School Bus > Shuttle Bus > Walk-In Van > S2 f151188 Fig. 7, For EPA10 and EPA04 engines, the starter path can be checked by loading the circuit at the alternator. 06/24/2013 f151189 Fig. 8, Location of the starter positive post. 5b.2 Load the system with the carbon pile to 500 amps. Record the voltage drop shown on the DMM. Combine the voltage drop of the positive and negative cable voltage drop tests; the total should not exceed 0.7 V. If total voltage drop is greater than 0.7 V, go to Check 6, then test voltage drop again. If total drop is less than 0.7 V, go to Check 6 but do not retest voltage drop. Starter Path Check — EPA07 Engines Amp Clamp and DMM Location: Engine: 5a. Amp clamp around POS starter cable for starter draw. Crank engine, under 30 sec. 5b. DMM on POS battery pack cable and POS starter post. Crank engine, under 30 sec. 5c. DMM on NEG battery pack cable and NEG starter post. Crank engine, under 30 sec. Combine the voltage from the positive and negative cable voltage drop tests. Rec Value Accept Value N/A + + = Less than max V drop in Table 2. On crank, the starter cable is likely to have between 400 and 1000 amps of current running through it. This test uses an amp clamp to view the crank amperage. The allowed voltage drop depends on the crank amperage. NOTE: This test may require an assistant. Starter Path Check – Checks 5a, 5b, and 5c – EPA07 only 5a - Measuring crank amperage with amp clamp 5a.1 Place an amp clamp on the positive starter cable, set it to read current between 400 and 1000 amps, and zero it. Make sure the ammeter can read, and is set to read, this range before proceeding. See Fig. 9. Page 6 Freightliner Custom Chassis Service Bulletin, 02/25/2019 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter > Recreational Vehicle > School Bus > Shuttle Bus > Walk-In Van > S2 02/17/2017 54-056 Freightliner Custom Chassis Service Bulletin f151191 Fig. 9, Measure the crank amperage with an amp clamp on the positive starter cable during crank. 5b - Starter positive cable voltage drop test 5b.1 Clip the DMM to the threaded portion of the positive post on the starter and the positive lead base of one of the batteries. 5b.2 Crank the engine. After the voltage reading normalizes (about 2 to 3 seconds), but before the engine starts, record the voltage drop shown on the DMM. IMPORTANT: Do not crank for longer than 30 seconds. Allow the starter to cool for 2 minutes between crank events. 5c - Starter negative cable voltage drop test 5c.1 Clip the DMM to the threaded portion of the negative post on the starter and the negative lead base of one of the batteries. 5c.2 Crank the engine. After the voltage reading normalizes (about 2-3 seconds), but before the engine starts, record the voltage drop shown on the DMM. Combine the voltage drop of the positive and negative cable voltage drop tests. Look up the crank amperage recorded using Table 2; total voltage drop from the two tests should not exceed the value given. If total voltage drop is greater than the allowed voltage, go to Check 6, then test voltage drop again. If total drop is within the allowed value, go to Check 6 but do not retest voltage drop. Max. Acceptable Combined V Drop by Amperage Max. Acceptable Amps Combined V Drop 375-449 0.6 450-549 0.7 Freightliner Custom Chassis Service Bulletin, 02/25/2019 Page 7 54-056 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter Freightliner Custom Chassis Service Bulletin > Recreational Vehicle > School Bus > Shuttle Bus > Walk-In Van > S2 Max. Acceptable Combined V Drop by Amperage Max. Acceptable Amps Combined V Drop 550-624 0.8 625-724 0.9 725-799 1.0 800-874 1.1 875-974 1.2 975-1025 1.3 Table 2, Max. Acceptable Combined V Drop by Amperage 6. Check all cable connections for corrosion and torque. Repair or replace if needed, then test again. Check 6 – Check all cable connections for corrosion and torque. See Fig. 10 and Fig. 11. Repair or replace if needed, then test again. Loose connections can cause intermittent problems as well as higher resistance, and are likely to have corrosion. Most battery labels will specify the torque value; if the torque value cannot be found, use 10 to 15 lbf·ft (13 to 20 N·m). 06/24/2013 f151194 Fig. 11, Check the battery connections for looseness and corrosion. Check the torque on the connections. 02/17/2017 f151192 Fig. 10, Check the positive post on the starter solenoid for loose cables and corrosion. ADDITIONAL BATTERY LOADS CHECK Page 8 Freightliner Custom Chassis Service Bulletin, 02/25/2019 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter > Recreational Vehicle > School Bus > Shuttle Bus > Walk-In Van > S2 54-056 Freightliner Custom Chassis Service Bulletin Key-off Loads 7. Key off, Load Disconnect Switch set to "Off" (if equipped). Wait 10 minutes for all loads to stop. Set amp clamp to a lower range setting. Zero amp clamp away from the vehicle. For each POS cable leaving batt pack, clamp the cable and record the amperage. If more than 1.0 amp, find sources of drain and remedy as needed. Rec Value + + + = Accept Value Add amps. Total must be less than 1 amp. Check 7 – Detail, Key-off Loads Check A key-off load is an electrical load that still draws current from the batteries when the ignition remains off, and in some cases, when the load disconnect switch is off. Some devices, such as the engine controller, the antilock braking system (ABS), and the radio memory, are intended to draw a very low current continuously. In long-term parking situations, however, these drains may discharge the batteries enough to cause a no-start condition. Key-off loads tend to be measured in milliamps (mA). 7.1 Set the Load Disconnect Switch to "Off." Shut the door, and wait 10 minutes after shutting the door for all "keep-alives" (signals sent between devices) to turn off. NOTE: On vehicles with a SAM module, the SAM will wake up for a self-check after 30 minutes of inactivity, then turn off. 7.2 Zero the amp clamp away from the vehicle to ensure that all battery draw—including "background" current—is detected upon measurement. The amp clamp should be set to a lower range, sensitive setting. 7.3 For each positive cable leaving the battery pack, clamp the cable and record the amperage. See Fig. 12. Add the amperages together. If the total is more than 1.0 amp, find the sources of drain and remedy as needed. 02/17/2017 f151195 Fig. 12, After zeroing the amp clamp away from the vehicle, measure the amperage in each positive cable leaving the battery pack. Finding Sources of Battery Drain Freightliner Custom Chassis Service Bulletin, 02/25/2019 Page 9 54-056 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter Freightliner Custom Chassis Service Bulletin > Recreational Vehicle > School Bus > Shuttle Bus > Walk-In Van > S2 Pull fuses individually on the circuit with the highest draw until the total combined amperage drops below 1.0 amp. From there, find the component on that particular circuit drawing the additional current. Repair or replace as needed. NOTE: Opening and shutting doors will wake up system keepalives. If a door is opened during the procedure, wait 10 minutes after closing the door before measuring draw. NOTE: The LVD (low voltage disconnect) could be bypassed by inverters or other aftermarket installed systems. Rec Value Key-on Loads 8. Amp clamp on POS alt cable. ENG at IDLE, turn on driver’s normal use loads. If load is more than 80% rated amps, find sources of draw and/or upgrade alternator. Retest after remedying. Accept Value Total less than 80% rated amps. Check 8 – Key-On Loads Check This test looks at the "normal use" loads of the vehicle during normal operation conditions by measuring draw at the alternator positive cable. "Normal use" should include high beams, radio, blower, and additional driver accessories. At idle, the total load should not be above 80% of the alternator’s rated output (e.g. 270 amps x .80 = 216 amps). See Table 2 for 80% load by alternator amperage rating. If the normal use load is higher, then a number of related issues can be at play that are outside the scope of this troubleshooting topic. These might include high-draw loads, and circuit voltage drop (from corrosion, looseness, or damage). Max. Acceptable Key-on Load by Alternator Amperage Rating Amp Max. Load 135 108 160 128 185 148 200 160 240 192 270 216 275 220 Table 3, Max. Acceptable Key-on Load by Alternator Amperage Rating If all systems are functioning properly, but the normal use load exceeds the alternator rating, either a higher rated alternator should be installed, or non-essential high-draw loads should be permanently removed from the system. CHARGING SYSTEM CHECK - ALTERNATOR Engine Throttle 9a. DMM on POS and NEG of batt pack. (Undercharge check) IDLE 9b. DMM on POS and NEG of batt pack. (Overcharge check) PARTIAL 9c. DMM on POS and NEG of batt pack. (Overcharge check) WIDE OPEN Page 10 Key Position KEY ON KEY ON KEY ON Carbon Rec Pile Value NO LOAD NO LOAD NO LOAD Accept Value 13.2-14.8 V 13.2-14.8 V 13.2-14.8 V Freightliner Custom Chassis Service Bulletin, 02/25/2019 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter > Recreational Vehicle > School Bus > Shuttle Bus > Walk-In Van > S2 54-056 Freightliner Custom Chassis Service Bulletin Carbon Pile: DMM: 10a.POS and NEG of batt pack. POS and NEG of batt pack. PARTIAL 10b.POS and NEG of batt pack. 70% of alt KEY ON rated 70% of alt POS and NEG of batt pack. WIDE OPEN KEY ON rated Within .2 V of Check 9 Within .2 V of Check 9 Checks 9a and 9b – Under and Overcharge Checks 9a. With a DMM, probe any battery in the primary battery pack at the negative and positive lead bases of the battery posts. With the engine running at idle and no loads turned on, record the voltage at the pack. 9b. With the engine running at partial throttle and no loads turned on, record the voltage at the pack. 9c. With the engine running at wide open throttle and no loads turned on, record the voltage at the pack. In both cases, the voltage should be above 13.2 V, and higher than it was before starting the engine. If not, the alternator is undercharging, and should be replaced. If the voltage reads above 14.8 V, the alternator is overcharging the batteries. Check the remote sense circuit before condemning the alternator. Check 10 – 70% of Rated Output Check 10a.1 With a DMM, probe any battery in the primary battery pack at the negative and positive battery posts. 10a.2 Clamp the carbon pile to the positive and negative battery pack leads. 10a.3 Place an amp clamp around the positive alternator cable. The amp clamp will be used to measure the total draw on the alternator from the carbon pile and other system loads. See Fig. 13. 02/17/2017 f151197 Fig. 13, Use an amp clamp around the positive alternator cable to measure the draw of the carbon pile. 10a.4 With the engine running at partial throttle, adjust the carbon pile until the amp clamp reads 70% of the alternator rated amperage (e.g. 270 amps x .70 = 189 amps). See Table 4. With this load applied, record the voltage at the battery pack. 10b. With the engine running at wide open throttle, adjust the carbon pile until the amp clamp reads 70% of the alternator rated amperage (e.g. 270 amps x .70 = 189 amps). See Table 4. With this load applied, record the voltage at the battery pack. Freightliner Custom Chassis Service Bulletin, 02/25/2019 Page 11 54-056 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter Freightliner Custom Chassis Service Bulletin > Recreational Vehicle > School Bus > Shuttle Bus > Walk-In Van > S2 While the load is applied, the voltage reading on the DMM should not drop more than 0.2 V below the reading in step 9b (the partial throttle, no load condition). If the voltage difference is more than 0.2 V, replace the alternator, then perform tests 9a, 9b, and 9c again to verify the repair. IMPORTANT: The voltage will drop if the carbon pile is drawing more than 70% of the alternator rating. Do not replace if a low voltage reading was seen with a load above 70%. Instead, test again with 70% of the alternator’s rated load. Target Carbon Pile Amp Draw by Alternator Rating Use Carbon Pile Draw of Alternator Rating (Amp) (Amp) 135 95 160 112 185 130 200 140 240 168 270 189 275 193 Table 4, Target Carbon Pile Amp Draw by Alternator Rating Remote Sense Check 11a.DMM on Rem Sense post, NEG on alt GND. 11b.DMM on POS of alternator, NEG on alt GND. Key Engine Position ENG OFF KEY OFF ENG OFF KEY OFF Carbon Rec Pile Value NO LOAD NO LOAD Accept Value Less than .05 V diff Remote Sense The remote sense circuit allows the alternator to directly measure battery voltage, in addition to the measurement it takes from the large cables. With these two voltage measurements, the alternator calculates the amount of voltage drop over the large cables and adjusts its output to provide the at-battery regulated voltage. Freightliner vehicles come equipped with either Delco Remy or Leece-Neville alternators, most of which have remote sense. Checks 11a and 11b – Remote Sense Check 11a. With the key off, place the DMM probes at alternator ground and remote sense post/terminal. See Fig. 14. Record the voltage. 11b. Place the DMM probes at the alternator body and the positive post of the alternator. Depending on the alternator, the positive post may be labelled "POS" "B+" or "+". Record the voltage. NOTE: Ground may be on a post, not the body, for some Leece Neville alternators. The values should be within .05 V. If voltage is out of specification, then the remote sense circuit may be shorted or open. First, check the remote sense fuse. The remote sense fuse is located in the Powernet Distribution Box (PNDB) on EPA10 vehicles (see Fig. 15), and in the Powertrain PowerNet Distribution Module (PTPDM) on EPA07 vehicles (see Fig. 16). Refer to the applicable workshop or service manual or EZ wiring for the remote sense fuse location on EPA07 or older vehicles. If the fuse is fine, look for opens or shorts in the remote sense circuit. Page 12 Freightliner Custom Chassis Service Bulletin, 02/25/2019 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter > Recreational Vehicle > School Bus > Shuttle Bus 54-056 Freightliner Custom Chassis Service Bulletin > Walk-In Van > S2 07/16/2013 f151199 Fig. 15, EPA10 vehicles: 5 amp remote sense fuse, location D in the Powernet Distribution Box (PNDB). 02/17/2017 f151198 Fig. 14, Clip the DMM positive to the remote sense post and the DMM negative to the alternator body. 07/16/2013 f151200 Fig. 16, EPA07 vehicles: 20 amp remote sense fuse, location F7 in the Powernet Distribution Module (PTPDM). If the remote sense fuse and circuit are fine, but the alternator is still overcharging, replace the alternator. 12 Check alternator mounting, pulley, and belt for proper condition and operation. Check 12 – Alternator Pulley, Belt, and Mounting Check the alternator drive belt for glazing, cracking, and wear. See Fig. 18. Check the belt tensioner for proper operation. Check that the alternator is securely fastened to the engine and that the pulley is in proper alignment with the drive belt system. Check for pulley damage. See Fig. 17. Repair or replace as necessary. See the vehicle workshop manual Group 01 – Engine for more information on drive belt and pulley inspection. Freightliner Custom Chassis Service Bulletin, 02/25/2019 Page 13 54-056 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter Freightliner Custom Chassis Service Bulletin > Recreational Vehicle > School Bus > Shuttle Bus 07/15/2013 > Walk-In Van > S2 f151148a Fig. 17, Types of Belt Damage Requiring Belt Replacement 01/19/2010 f151149 Fig. 18, Pulley Damage Requiring Pulley Replacement Troubleshooting the Starting System Before using the Starting System Troubleshooting, complete the Powernet Troubleshooting Worksheet. Batteries, cables, and the alternator must be checked for correct function before troubleshooting the starter. This troubleshooting should not be performed until the Powernet Troubleshooting Worksheet has been completed. Page 14 Freightliner Custom Chassis Service Bulletin, 02/25/2019 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter > Recreational Vehicle > School Bus > Shuttle Bus > Walk-In Van > S2 54-056 Freightliner Custom Chassis Service Bulletin Crank the engine with no loads (headlights, blower, etc.). Identify the symptom. Symptom: Grinding Noise Remove the starter and check the pinion and ring gear for damage. See Fig. 19. • If damage is found, replace damaged parts as needed. • If no damage is found, replace the starter. Symptom: No Crank or Intermittent Crank NOTE: Uncleared abutments should not happen more frequently than approximately 1 out of 100 starts. Test the mag switch using a DMM (positive probe on the IMS input signal, negative probe on a known good ground) while cranking: • If less than 9 V, FAIL: − For Cascadia, use DiagnosticLink to check the Starter Relay Output signal. If the signal is present, check SAM Cab connector X19 pin 3 for continuity. − For Business Class M2, use ServiceLink to check the Starter Relay Output signal. If the signal is present, check bulkhead module connector B4 pin B for continuity. − For all other models, troubleshoot the circuit and check all of the applicable starter interlocks and control systems. Find more information using PartsPro and EZwiring. • If greater than or equal to 9 V, PASS; with the key off, rotate the engine 90 degrees using a barring tool. Remove the tool, and try to crank the engine again: − If the engine was hard to turn over and still does not crank, consult the engine manufacturer. − If the engine cranks, shut down the engine, remove the starter, and inspect the starter pinion and ring gear. See Inspecting the Ring Gear. Replace damaged parts if found. If no damage is found, replace the starter. Symptom: Slow Turnover If the ambient temperature is less than 32°F (0°C), slow turnover is normal. If the ambient temperature is greater than 32°F (0°C), check the engine for faults and check the condition of the engine oil. If fault codes are found, or the engine oil indicates an issue, consult the engine manufacturer. If there are no fault codes, and the engine oil passes inspection, replace the starter. Freightliner Custom Chassis Service Bulletin, 02/25/2019 Page 15 54-056 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter Freightliner Custom Chassis Service Bulletin OK > Recreational Vehicle > School Bus > Shuttle Bus > Walk-In Van > S2 6 OK 7 5 4 3 2 1 f151145a 08/28/2013 06/13/2013 f151163a Fig. 19, Acceptable and Unacceptable Ring Gear Wear 1. Over Crank Protection (OCP) 2. Insulated Ground Terminal 3. Battery Terminal 4. 5. 6. 7. Ground Terminal Solenoid Switch IMS Input Signal Magnetic Switch (IMS) Fig. 20, Starter Components and Terminals Warranty This is an informational bulletin only. Warranty does not apply. PowerNet Assessment Worksheet - Do Entire Worksheet in Order (Checks 1 to 12) IMPORTANT: Record the initial value of each check on the worksheet before performing repairs. BATTERIES CHECK 1. 2. 3. DMM (Digital Multimeter): POS and NEG batt pack. Check battery pack voltage to determine state of charge. Charge pack to 100%. If unable, go to 3, "Break pack." Remove surface charge: HVAC blower, lights on, 5 min. Break pack into individual batteries and test each with an approved battery tester. (Remove NEG cables first!) Replace batteries if instructed by the tester. All batteries must pass the battery tester evaluation before troubleshooting continues. Rec Value Batt Batt Batt Batt 1: 2: 3: 4: Accept Value 12.8V AGM 12.6V Flood PASS PASS PASS PASS or or or or FAIL FAIL FAIL FAIL PATH CHECK - CABLE VOLTAGE DROP TEST Page 16 Freightliner Custom Chassis Service Bulletin, 02/25/2019 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter > Recreational Vehicle > School Bus > Shuttle Bus > Walk-In Van > S2 54-056 Freightliner Custom Chassis Service Bulletin Alternator Path Check Carbon Pile: DMM: 4a. POS alternator, GND alternator. Load at alternator-rated amps. POS alternator, POS batt pack 4b. POS alternator, GND alternator. Load at alternator-rated amps. NEG alternator, NEG batt pack Combine the voltage from the positive and negative cable drop tests. Rec Value Accept Value + + = Total less than 0.7 V IMPORTANT: EPA10/EPA04 and EPA07 vehicles require different starter path checks because of differences in cable routing. IMPORTANT: If the positive alternator cable is smaller than 2/0 AWG, use "Starter Path Check - EPA07." NOTE: EPA07 vehicles with jump start posts connected to the starter can be tested using the EPA10/EPA04 check by placing the carbon pile clamps on the jump start posts instead of the alternator in 5a and 5b. Starter Path Check — EPA10, EPA04 Engines Rec Value Carbon Pile: DMM: 5a. POS alternator, GND alternator. Load at 500 amps. POS starter, POS batt pack + 5b. POS alternator, GND alternator. Load at 500 amps. NEG starter, NEG batt pack + Combine the voltage from the positive and negative cable voltage drop tests. = 6. Check all cable connections for corrosion and torque. Repair or replace if needed, then test again. Starter Path Check — EPA07 Engines Rec Value Amp Clamp and DMM Location: Engine: 5a. Amp clamp around POS starter cable for starter draw. Crank engine, under 30 sec. 5b. DMM on POS battery pack cable and POS starter post. Crank engine, under 30 sec. + 5c. DMM on NEG battery pack cable and NEG starter post. Crank engine, under 30 sec. + Combine the voltage from the positive and negative cable voltage drop tests. = 6. Check all cable connections for corrosion and torque. Repair or replace if needed, then test again. Amps 375-449 450-549 550-624 625-724 725-799 800-874 875-974 975-1025 Accept Value Total less than 0.7 V Accept Value N/A Less than max V drop in Table 5. Max. Acceptable Combined V Drop 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 Table 5, for Check 5, Max. Acceptable Combined V Drop by Amperage ADDITIONAL BATTERY LOADS CHECK Key-off Loads Freightliner Custom Chassis Service Bulletin, 02/25/2019 Rec Value Accept Value Page 17 54-056 Powernet Troubleshooting Guide: Batteries, Path, Alternator, and Starter Freightliner Custom Chassis Service Bulletin > Recreational Vehicle > School Bus > Shuttle Bus > Walk-In Van > S2 7. Key off, Load Disconnect Switch set to "Off" (if equipped). Wait 10 minutes for all loads to stop. Set amp clamp to a lower range setting. Zero amp clamp away from the vehicle. For each POS cable leaving batt pack, clamp the cable and record the amperage. If more than 1.0 amp, find sources of drain and remedy as needed. Key-on Loads 8. Amp clamp on POS alt cable. ENG at IDLE, turn on driver’s normal use loads. If load is more than 80% rated amps, find sources of draw and/or upgrade alternator. Retest after remedying. CHARGING SYSTEM CHECK - ALTERNATOR Engine Throttle 9a. DMM on POS and NEG of batt pack. (Undercharge check) IDLE 9b. DMM on POS and NEG of batt pack. (Overcharge check) PARTIAL 9c. DMM on POS and NEG of batt pack. (Overcharge check) WIDE OPEN Carbon Pile: DMM: Key Position KEY ON KEY ON KEY ON + + + = Carbon Rec Pile Value NO LOAD NO LOAD NO LOAD 70% of alt KEY ON rated 70% of alt 10b.POS and NEG of batt pack. POS and NEG of batt pack. WIDE OPEN KEY ON rated If value is outside acceptable range, replace alternator and retest system. Remote Sense Check 11a.DMM on Rem Sense post, NEG on alt GND. ENG OFF KEY NO LOAD OFF KEY 11b.DMM on POS of alternator, NEG on alt GND. ENG OFF OFF NO LOAD If remote sense voltage is outside range, but the remote sense fuse and circuit are ok, replace alternator. 12. Check alternator mounting, pulley, and belt for proper condition and operation. 10a.POS and NEG of batt pack. Page 18 POS and NEG of batt pack. PARTIAL Add amps. Total must be less than 1 amp. Total less than 80% rated amps. Accept Value 13.2-14.8 V 13.2-14.8 V 13.2-14.8 V Within .2 V of Check 9 Within .2 V of Check 9 Less than .05 V diff Freightliner Custom Chassis Service Bulletin, 02/25/2019