KC-2040

9/29/2020
Content creation stages KC-2040
P21CA00 And Other Power Faults Leading To
Communication Faults And SCR Inducement
(Derate)
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Background
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It is possible that a progressive loss of electrical power to the Aftertreatment
Control Module (ACM) will result in the ACM cutting power to the Exhaust
Aftertreatment System (EATS) sensors – NOx, Particulate Matter (PM) and
DEF Quality, Level and Temperature sensor. This triggers communication
faults for these sensors and ultimately puts the system into SCR
Inducement. The root cause is often related to loss of power or battery
voltage and/or grounding issues. The instruction below describes the most
likely causes and provides steps for troubleshooting.
Symptoms
• Presence of P21CA along with other ACM power and communication
faults P220A, P220B, P24D0, U029D, U029E, U02A2, U02A3, P0562.
• SCR inducement and/or derate.
P21CA00
Reductant Control Module Supply Voltage
P220A1C
NOx Sensor Supply Voltage Circuit (Bank 1 Sensor 1)
P220B1C
NOx Sensor Supply Voltage Circuit (Bank 1 Sensor 2)
P24D000
Par culate Ma er Sensor Supply Voltage Circuit Low
U029D00
Lost Communica on With NOx Sensor "A"
U029E00
Lost Communica on With NOx Sensor "B"
U02A200
Lost Communica on with Reductant Quality Module
U02A300
Lost Communica on With PM Sensor
P056200
ECU Ba ery Poten al Below Range
This pattern of codes indicates that there are issues with the ACM power
supply or ground connections. Typically, this combination develops over
time as a connection deteriorates. Eventually the effective voltage to the
ACM drops below 8V and there is insufficient power to support the sensors
controlled by the ACM - NOx, PM and DEF level/temp sensors.
Communication is lost to these devices.
Once sensor communication codes (U029D, U029E, U02A2) are triggered,
the truck will go into SCR Inducement followed by derate.
The graphic below shows the voltage related DTCs for
emissions components, as well as the voltage at which they will set and the
amount of time that voltage must remain at that level for the fault to
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log. This graphic is for informational purposes only and should not be
used for diagnosis.
Diagnosis And Repair
IMPORTANT
Presence of any combinations of P24D0, P21CA, P0562,
generally does NOT indicate the ACM is 'bad' or a PM
sensor is 'bad'.
Required Tools
Part Number
9998699
9990014
88890074 (or equivalent)
Description
Break-Out Box
62-Pin ACM Connector Harness
Multimeter
Quantity
1
1
1
Initial Checks
This combination of faults is frequently caused by a loose or
faulty connection on battery power or ground (but not fully disconnected - if
fully disconnected, DTCs U116F and U010E would also be present).
• Check that ALL the ACM power and ground connections are securely
tightened.
- Ensure battery nuts are tightened to 15 lb-ft (20 Nm).
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- Ensure multiple ring terminals on a common stud are fanned out and
lying flat against each other.
- Ensure ring terminals and other contact points are clean and free
from any terminal protectant coating or wax.
• If there is no evidence of loose battery connections: Continue to the
checks below.
Other items to check
1. Check the battery condition as follows:
1.1. Check the complete battery pack voltage.
1.1.1. Start the truck.
1.1.2. Run the engine at fast idle (1000 RPM) for 1 minute.
1.1.3. Turn the truck off, then return the key to the ON position.
1.1.4. Check voltage with all of the batteries still connected to
one another.
• All battery positive terminals are connected together by
busbars or cables, and all battery negative terminals are
connected together.
1.1.5. Make a note of the voltage and evaluate results:
• For a fully charged system, in good condition, the
voltage should be 12.4 - 12.6V for standard flooded
lead-acid batteries, or 12.6 - 12.8V for AGM-type
batteries.
• Low battery voltage is indicative of an inadequate
charging system
- Potential causes include corroded cables, dirty
connections and/or weak or defective batteries.
1.2. Check individual battery condition.
1.2.1. Disconnect the busbars and cables.
1.2.2. Inspect and clean all interconnecting terminals. Ensure
there is no corrosion.
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1.2.3. Check each battery voltage and perform a load test on
each battery individually.
1.2.4. Evaluate results:
• If one battery's voltage is significantly lower than
the others, or lower than the measurement from Step
1.1.5, OR fails a load test: The battery may be bad or
there may be a connection issue such as excessive
corrosion on the busbar or terminal, inhibiting proper
charging.
1.2.5. Replace or clean any corroded part as needed.
1.2.6. Reconnect the busbars and/or cables.
1.3. Check the battery pack voltage while charging system is
active.
1.3.1. Start the truck.
1.3.2. Run the engine at fast idle (1000 RPM) for 1 minute.
1.3.3. With the engine still running, recheck battery voltage:
• Voltage should rise to 13.5-14.5V rapidly.
• If the voltage is less than 13V: Run then engine for an
additional minute and recheck, as the batteries may have
been deeply discharged.
1.3.4. Evaluate results:
• If the voltage remains less than 13V: There is an
issue with the alternator or the alternator belt.
• If the alternator belt is in good condition, there is an
issue with the alternator.
For the following 2 checks, use the ACM ring terminal at the
frame rail as a reference.
NOTE: Ensure clean contact is made to the meter probes.
2. With key on, engine off, verify battery power feed to ACM pins 53, 57, and
60 is the same as same as battery voltage (Vbat).
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3. Verify that ACM pin 3 also sees Vbat (this is the ignition voltage pin).
If the ACM is not seeing Vbat there is an issue in the power supply path from
battery power to ACM (check in-line fuse, wiring, etc.).
4. Verify voltage at the ACM grounds pins 55, 58, and 61, relative to the
battery negative is <0.5V with ignition on.
• If the difference is greater than 0.5V: there may be an issue with
elevated resistance on the ground path (corrosion on the ring
terminal; corroded, damaged, or loose pins; etc.).
5. Verify that ACM pin 49 shows a constant voltage close to Vbat relative to
the ground ring terminal as follows:
• If pin 49 shows 9-11V: This is a sign of reduced voltage. There
could be something causing an intermittent voltage drop.
- Examples include corrosion on the ground path, chafed wire,
water intrusion, etc.
• If pin 49 shows <5 V: There is a definite voltage drop below
normal–see potential causes above.
For the following checks, individual sensors will trigger
communication faults when they are disconnected from the EATS
harness. These steps are necessary for diagnosis and the faults may be
cleared afterward.
If pin 49 voltage is still dropping below expected voltage:
Work through the following steps one sensor at a time in the following
order:
•
•
•
•
PM Sensor
DEF Quality (level and temperature) Sensor
Inlet NOx Sensor
Outlet NOx Sensor
• For each sensor:
1. Cycle the key off.
2. Allow the system to fully power down for 1 minute.
3. Unplug the sensor and cycle power back on.
• If the voltage at pin 49 recovers to Vbat: There is an issue
with the sensor being checked.
• If the voltage reading remains unchanged: Another
component is the culprit. Reconnect the sensor being checked
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and proceed to the next sensor
• If a sensor is found to be faulty:
- Check for the presence of corrosion or contamination in the sensor
connector.
- Corrosion can also appear on the mating harness connector and this
should be addressed to ensure integrity of connection.
• For any trucks that show PM sensor issues: Verify that the exhaust
pipe contamination fix is implemented.
- See FSB 284-069 Exhaust Particulate Sensor, Repair (2017
Vehicles). This applies to vehicles manufactured between 1/1/2017
and 11/15/2017.
○ FSB 284-069 can be found under the Service tab of Impact.
○ Search for "284-069" (Without quotes) under the Additional
Search Values section. Make sure 'Titles' is selected from the
dropdown menu.
• If sensors are NOT found to be the problem and pin 49 voltage is still
dropping below expected voltage:
1. Cycle the key off. Allow the system to fully power down for 1 minute.
2. Disconnect the DPF/EATS harness.
- If voltage is restored from this exercise: Then the issue is in the
harness.
- If voltage remains the same: Repeat for the jumper harness to the
DEF Quality Sensor and pump.
3. Inspect the harness found to be causing voltage drop..
- Harness issues such as water intrusion, damaged harness, etc. can
cause short circuits, and affect voltage.
a
Tags
P21CA00
P220A1C
P220B1C
P24D000
U029D00
U029E00
U02A200
U02A300
P056200
P21CA 00
P220A 1C
U02A3 00
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P056200
P21CA-00
P0562-00
ACM POWER
P220B-1C
P24D0-00
Content creation stages KC-2040
P220A-1C
U02A3-00
EATS DATALINK
U029D-00
U029E-00
U02A2-00
Feedback
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Printed by:BRADLEY PICKENS
Service
Chassis ID
Path
284/Bulletins/Information//FSB 284-069, Exhaust Particulate Sensor, Repair (2017 Vehicles)
Model
Identity
145526930
Publish date
7/16/2020
ID/Operation
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by
the Volvo Group
The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
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FSB 284-069, Exhaust Particulate Sensor, Repair (2017 Vehicles)
(July 2020)
Some trucks built between 1/1/2017 and 11/15/2017 may experience a Particulate Matter (PM) Sensor fault that can
result in the MIL lamp illuminating. These faults may be P24DA, “PM Sensor Exhaust Sample Error,” or P24D1, “PM
Sensor Regen Incomplete.” These faults may be caused by contamination of the PM sensor. In order to reduce the
likelihood of sensor contamination, new exhaust pipe parts are being made available that contain an internal water
management feature along with an integrated drain that will prevent contamination of the sensor. If either of these two
faults occur, follow the instructions outlined in this bulletin to clean the exhaust pipes and install a new exhaust pipe
with the new contamination prevention measures.
Required Parts – All Years
Inspect and replace the v-band clamp as needed
A new gasket will be needed when disconnecting the SCR exit.
Note: No gasket needed for vertical SCR.
Part Description
SCR Gasket
V-band Clamp
Particulate Matter Sensor
Part Number
21095726
21021850
23320447
Note: Customer adaptations can change required parts. Check for adaptations before ordering parts. (For example,
under-slung exhaust)
Repair Procedure
Determine which Flex Pipe and Clamp the truck currently has installed on it. If the truck you are repairing has the Flex
Pipe and Clamp shown in scenario 1, you will need to order the improved Flex Pipe (P/N 21142254) and Clamp (P/N
25172497). If the truck you are repairing has the Flex Pipe and Clamp shown in scenario 2, this truck already has the
improved parts and ordering a new Flex Pipe and Clamp is NOT required.
Scenario 1
This style
Flex Pipe
and Clamp
will no
longer work
with the
upper
adjacent
connecting
pipe. The
below parts
in scenario 2
are required
to perform
this FSB.
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by
the Volvo Group
The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
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IMPACT 4.07.80
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Follow the
repair below
that is
applicable
for your
configuration.
Scenario 2
This style
Flex Pipe
and Clamp
only needs
the upper
adjacent
pipe
replaced.
Reuse the
existing Flex
Pipe and
Clamp, or
order as
needed.
Flex Pipe –
21142254
Clamp –
25172497
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by
the Volvo Group
The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
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Follow the
repair below
that is
applicable
for your
configuration.
Table of Contents
Model
Cab Type Exhaust
Configuration
VNL
Day Cab Single Outlet
Right
Side Outboard
VHD Axle Fwd Day Cab Single Outlet
Right
Side Outboard
VNM, VHD
Day Cab Single Outlet
Axle Bwd
Right
Side Outboard
VHD Axle Bwd Day Cab Dual Outlet
VHD Axle Fwd Day Cab Dual Outlet
VNM, VHD,
Sleeper Single Outlet
VNL
Cabs
Right Side
Repair
Number
1
2
3
4
4
5
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the Volvo Group
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IMPACT 4.07.80
VNM, VHD,
VNL
9/29/2020
Sleeper
Cabs
Outboard
Dual Outlet
Single Outlet
Right Side
Outboard
Dual Outlet
6
Repair 1
ModelCab Exhaust
Pipe 1
Type Configuration (Stack)
Pipe 2
Flex Pipe Clamp
(SCR
Elbow)
VNL Day Single
238731232218198120442244Clamp
Cab Outlet Right
25172497
Side
x2
Outboard
Repair 2
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by
the Volvo Group
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IMPACT 4.07.80
Model
VNM
/VHD
Cab
Type
Day
Cab
9/29/2020
Exhaust Configuration
Pipe 1
Single Outlet Right Side
Inboard
23630037
Repair 3
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by
the Volvo Group
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IMPACT 4.07.80
Model Cab Type Exhaust
Configuration
VNM 430/630 Single Outlet Right
/VHD Sleeper Side Inboard
9/29/2020
Pipe 1
(Not Bright)
23154798
Caution
(Bright)
23154799
Repair 4
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the Volvo Group
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IMPACT 4.07.80
Model
Cab
Exhaust
Type
Configuration
Day Cab Dual Outlet
VHD Axle
Bwd
VHD Axle Fd Day Cab Dual Outlet
9/29/2020
Pipe 1
23155774
23155785
Repair 5
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by
the Volvo Group
The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
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IMPACT 4.07.80
ModelCab
Exhaust Configuration
Type
VNM Sleeper Single Outlet Right
VHD Cabs
Side Outboard
VNL
9/29/2020
Pipe 1
(Not Bright)
23154798
(Bright)
23154799
Repair 6
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by
the Volvo Group
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IMPACT 4.07.80
ModelCab
Type
VNM Sleeper
VHD Cabs
VNL
9/29/2020
Exhaust
Pipe 1
Note
Configuration
Dual Outlet (Not
Requires 2
Right Side Bright)
elbows per
Outboard
23154798 chassis
(Bright)
23154799
Instructions
1. Decommission the vehicle. Install wheel chocks and disconnect the battery.
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the Volvo Group
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2.
3.
4.
5.
6.
7.
8.
9.
Remove the PM sensor and module.
Remove all exhaust pipes up to the SCR outlet pipe.
Pressure wash the inside of each pipe that will be reused.
Reassemble the exhaust system using the new parts referenced in the table above.
Mark the SCR outlet pipe 1.5" from the end also mark the new pipe (not flex) 1.5" from its inlet.
Slip the flex pipe as for over the SCR outlet pipe as possible.
Install the new exhaust pipe.
Using a new clamp assemble the new exhaust pipe to the new flex pipe using the 1.5" mark to get the correct amount
of overlap.
10. Slide the assembly into place using the 1.5" mark on the SCR outlet as a reference point and to ensure the correct
amout of overlap, once in both pipes are in place use clamps to secure.
Note: Correct installation is achieved when the flex pipe is in a "relaxed" state, there should be no compression or
expansion visible on oposing sides of the pipe after installed.
11. Install the new PM sensor and module.
Note: Do not use any lubricant of any kind on the PM sensor threads.
Note: Align the tab on the sensor with the slot.
12. Torque the sensor to 35 +/- 5 Nm (26+/- 4 Ft lb)
13. Install the sensor module.
14. Torque the nuts to
M6: 10 +/- 5 Nm (88 +/- 3 in lb)
M8: 24 +/- 4 Nm (17.1 +/- 3 ft lb)
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by
the Volvo Group
The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
15.
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15. Install the wire ties and clamps.
Note: Use high temperature cable ties.
16. Connect the battery.
17. Clear any DTC codes.
18. Remove the wheel chocks.
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by
the Volvo Group
The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
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Reimbursement
This repair may be eligible for
UCHP
reimbursement if a product failure
Reimbursement
was experienced within time and
mileage limits of the applicable
Warranty coverage. Reimbursement
is obtained via the normal claim
handling process.
Claim Type (used only when
W
uploading from the Dealer Bus. Sys.)
Labor Code
Primary Labor Code (Exhaust
2846-16-09-02
Particulate Sensor, Repair)
See table for
times.
Causal Part
22946032
Labor Times Reference – 2017 Vehicles
Model
VNL
VNM
VHD
VHD
VNM
VHD
VNL
Cab Type Exhaust
Configuration
Day Cab Single Outlet
Right Side
Outboard
Day Cab Dual Outlet
Sleeper Single Outlet
Cabs
Right Side
Outboard
Dual Outlet
Pipe 1
1.5
2.9
3.5
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by
the Volvo Group
The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
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