PIE0604

Subject:
Engineering Information - Service 4WD Message Illuminated On the Drivers Information Center (DIC), DTC C15AC Set
Attention:
Proceed with this EI ONLY if the customer has commented about this concern AND the PIE number is listed in the
Global Warranty Management / Investigate History link (GWM/IVH). If the customer has not commented about this
condition or the EI does not show in GWM/IVH, disregard the PIE and proceed with diagnostics found in published
service information. THIS IS NOT A RECALL — refer to Service Bulletin 04-00-89-053 for more details on the use of
Engineering Information bulletins.
Brand:
Model:
Chevrolet
Silverado 2500HD/3500HD
GMC
Sierra 2500HD/3500HD
Model Year:
VIN:
from
to
from
to
2020
2021
-
-
Engine:
Transmission:
-
-
Involved Region or Country
North America
Additional Options (RPOs)
Equipped with TRANSFER CASE-ELECTRIC SHIFT CONT, TWO SPEED, ALUM (RPO NQF)
Condition
Important: If the customer did not bring their vehicle in for this concern, DO NOT proceed with this EI.
Some customers may comment on the service 4WD message illuminated on the drivers information center (DIC).
Technicians may find DTC C15AC set.
GM Engineering is attempting to determine the root cause of the above condition. Engineering has a need to
gather information on vehicles PRIOR to repair that may exhibit this condition. As a result, this information will be
used to "root cause" the customer's concern and develop/validate a field fix.
Cause
Correction
If you encounter a vehicle with the above concern, perform the following steps and contact the engineers listed below with your findings.
1.
When did the customer first notice the service 4WD message illuminated on the drivers information center (DIC). Upon start up or while driving?
2.
Which drive mode was active, (2WD / 4WD / 4LO), that the customer first notice when the service 4WD message illuminated on the DIC?
3.
Does the customer remember if they were shifting the 4WD system prior to noticing the Service 4WD message?
4.
Which scenario listed below best describes the customers 4WD usage?
5.
–
The customer always uses 2WD and rarely uses 4WD
–
The customer mostly uses 2WD and sometimes uses 4WD
–
The customer uses 2WD and 4WD about the same amount
–
The customer mostly uses 4WD and sometimes uses 2WD
–
The customer always uses 4WD and rarely uses 2WD
Did anything else unusual occur (driving scenario, battery voltage, other failure, etc) that you think could be related to the service 4WD message?
Contact Information
The Contact Information has been redacted.
Please include the following information if leaving a message:
–
Technician name
–
Dealer name and phone number
–
Complete VIN and repair order (R.O) number
1
On the repair order, document the date and time the call was placed (even if the engineer was not reached).
If engineering is unable to return the call within one hour, proceed with diagnosis and repair based on information found in SI.
Warranty Information
If engineer was contacted or required information was provided, use:
Labor Operation
Description
Labor Time
8481928*
Engineering Information - Service 4WD Message Illuminated On (DIC), DTC
C15AC Set
0.4 hr
* This is a unique labor operation for bulletin use only.
Version
1
Modified
Released December 04, 2020
2