Bulletin No.: PIP5838B
Published date: 06/2/2022

Preliminary Information
PIP5838B Service Diesel Exhaust Fluid Tank Wiring Harness Pinout
Change. Possible DTCs P20B9 and or P20C1
Models
Brand:

Model:

Model Years:

VIN:
from

to

Engine:

Transmissions:

Chevrolet

Silverado 2500HD/3500HD

2020 - 2022

All

All

6.6 L5P

All

GMC

Sierra 2500HD/3500HD

2020 - 2022

All

All

6.6 L5P

All

Involved Region or Country United States, Canada, Israel, Palestine, Australia/New Zealand
A technician may nd the schematics and connector end view in Service Information
do not match the pin location on the A38 reductant pump/sender assembly
connector (16 way connector). This will occur if the DEF tank has been replaced on a
2020 – early build 2022 (herein known as early build) and will typically result in DTCs
P20B9 and/or P20C1 setting.
There was a change to the DEF tank harness for service.

Condition

Cause

Correction:
Model years 2020 through early build 2022 were originally built with cavities 6, 12 and 13 unoccupied. After midyear 2022 (herein known as late build), the pump/sender assembly and the corresponding connector terminals
were moved. Terminal 10 was moved to cavity 12 and terminal 11 was moved to cavity 6. All tanks built after that
date, including tanks to service the 2020 – early build 2022 are con gured this way. If it is necessary to replace
the reductant tank in an early build vehicle, it will come with the correct harness already installed and installation
would proceed with no special instructions.

If it becomes necessary to perform diagnostics on an early build vehicle with the updated reductant tank installed,
you can use the 2022 late build schematics and connector end view or the tables below.

The early build harnesses are still available to service a damaged harness but only if it has the original reductant
tank.

First Design:
Pin
1

Wiring Harness Part Numbers 85108194, 84876221, 84831758, 84230960
Function
Diesel Exhaust Fluid Tank Temperature Sensor Signal

2
3
4
5

Diesel Exhaust Fluid Tank Temperature Sensor Feedback Signal
Diesel Exhaust Fluid Pressure Sensor Low Reference
Diesel Exhaust Fluid Pressure Sensor Signal
Diesel Exhaust Fluid Pressure Sensor 5 Volt Reference

6
7

Not Occupied
Diesel Exhaust Fluid Smart Pump Control

8
9
10

Diesel Exhaust Fluid Smart Pump Supply Voltage Phase 2
Diesel Exhaust Fluid Reservoir Heater Control
Diesel Exhaust Fluid Heating Tank 2 Heater Control

11
12

Diesel Exhaust Fluid Tank Heater Low Control
Not Occupied

13
14
15
16

Not Occupied
Diesel Exhaust Fluid Pump Motor Stator Low Reference
Diesel Exhaust Fluid Heating Tank 2 Heater Control Low
Diesel Exhaust Fluid Smart Pump Supply Voltage Phase 3

Second Design:
Wiring Harness Part Number 85138745
Function

Pin
1
2
3
4
5
6
7
8

Diesel Exhaust Fluid Tank Temperature Sensor Signal
Diesel Exhaust Fluid Tank Temperature Sensor Feedback Signal
Diesel Exhaust Fluid Pressure Sensor Low Reference
Diesel Exhaust Fluid Pressure Sensor Signal
Diesel Exhaust Fluid Pressure Sensor 5 Volt Reference
Diesel Exhaust Fluid Tank Heater Low Control
Diesel Exhaust Fluid Smart Pump Control
Diesel Exhaust Fluid Smart Pump Supply Voltage Phase 2

9
10
11
12
13
14
15

Diesel Exhaust Fluid Reservoir Heater Control
Not Occupied
Not Occupied
Diesel Exhaust Fluid Heating Tank 2 Heater Control
Not Occupied
Diesel Exhaust Fluid Pump Motor Stator Low Reference
Diesel Exhaust Fluid Smart Pump Supply Voltage Phase 3

16

Diesel Exhaust Fluid Heating Tank 2 Heater Control Low

Version History
Version
Modi ed

3
02/15/2022 - Created on.
03/09/2022 - Updated to seperate tables and refer to SI.
06/02/2022 - Updated to clarify early and late build models and for
schematic clari cations.

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