SB54-278

Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
54-278
Freightliner
Service Bulletin
Description of Revisions:This bulletin replaces the version dated
5/31/2017. Information is added about the BCT-460DTNA
PowerNet Assessment Tool.
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.
Freightliner Service Bulletin, 06/11/2018
Page 1
54-278
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
Freightliner
Service Bulletin
+
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
+
−
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
+
+
+
+
−
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
−
−
−
−
−
−
+
08/16/2013
f151181a
+
08/16/2013
Fig. 1, EPA04, and EPA10 and newer: the alternator
routes through the starter. Use "Starter Path Check —
EPA10, EPA04 Engines" for Check 5.
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.
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
Page 2
AGM
12.8
12.6
12.4
12.2
12
SoC
100%
80%
60%
40%
20%
Freightliner Service Bulletin, 06/11/2018
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
Flooded
11.8
Freightliner
Service Bulletin
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
AGM
11.8
54-278
SoC
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.
All batteries must pass the battery tester evaluation before troubleshooting continues.
Batt
Batt
Batt
Batt
1:
2:
3:
4:
PASS
PASS
PASS
PASS
or
or
or
or
FAIL
FAIL
FAIL
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.
Freightliner Service Bulletin, 06/11/2018
Page 3
54-278
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
Freightliner
Service Bulletin
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
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:
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: 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.
Page 4
Freightliner Service Bulletin, 06/11/2018
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
54-278
Freightliner
Service Bulletin
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
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.
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
Freightliner Service Bulletin, 06/11/2018
Page 5
54-278
Freightliner
Service Bulletin
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
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.
06/24/2013
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:
5a. Amp clamp around POS starter cable for starter draw.
Page 6
Engine:
Crank engine, under 30 sec.
Rec
Value
Accept
Value
N/A
Freightliner Service Bulletin, 06/11/2018
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
54-278
Freightliner
Service Bulletin
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
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.
+
+
=
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.
02/17/2017
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
Freightliner Service Bulletin, 06/11/2018
Page 7
54-278
Freightliner
Service Bulletin
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
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
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).
Page 8
Freightliner Service Bulletin, 06/11/2018
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
54-278
Freightliner
Service Bulletin
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
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
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.
Freightliner Service Bulletin, 06/11/2018
Page 9
54-278
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
Freightliner
Service Bulletin
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
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
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.
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.
Rec
Value
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.
Page 10
Freightliner Service Bulletin, 06/11/2018
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
54-278
Freightliner
Service Bulletin
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
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
Carbon Pile:
DMM:
10a.POS and NEG of batt pack.
POS and NEG of batt pack. PARTIAL
10b.POS and NEG of batt pack.
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
POS and NEG of batt pack. WIDE OPEN KEY ON rated
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
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.
Freightliner Service Bulletin, 06/11/2018
Page 11
54-278
Freightliner
Service Bulletin
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
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.
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
Page 12
Freightliner Service Bulletin, 06/11/2018
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
Remote Sense Check
11a.DMM on Rem Sense post, NEG on alt GND.
11b.DMM on POS of alternator, NEG on alt GND.
Freightliner
Service Bulletin
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
Key
Engine
Position
ENG OFF KEY OFF
ENG OFF KEY OFF
54-278
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.
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.
Freightliner Service Bulletin, 06/11/2018
Page 13
54-278
Freightliner
Service Bulletin
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
07/16/2013
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
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.
Page 14
Freightliner Service Bulletin, 06/11/2018
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
54-278
Freightliner
Service Bulletin
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
07/15/2013
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.
Freightliner Service Bulletin, 06/11/2018
Page 15
54-278
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
Freightliner
Service Bulletin
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
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.
Page 16
Freightliner Service Bulletin, 06/11/2018
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
OK
54-278
Freightliner
Service Bulletin
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
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
Freightliner Service Bulletin, 06/11/2018
Page 17
54-278
Freightliner
Service Bulletin
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
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
Page 18
Rec
Value
Accept
Value
Freightliner Service Bulletin, 06/11/2018
Powernet Troubleshooting Guide: Batteries, Path, Alternator,
and Starter
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
> Century Class Conventional
> Argosy COE
Cargo
> Columbia
> 122SD and Coronado
54-278
Freightliner
Service Bulletin
> Business Class M2
> Cascadia
> 108SD/114SD
> New Cascadia
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.
Freightliner Service Bulletin, 06/11/2018
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
Page 19