Subject:

Engineering Information - Malfunction Indicator Lamp (MIL) Illuminated on Driver Information Center (DIC), DTCs
P31A0, P31A1, P31A2, P31A3, P31A4 and/or P31A5 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:

BrightDrop

EV600

GMC

HUMMER EV

Model Year:

HUMMER EV SUV

VIN Breakpoint:

from

to

from

to

2022

2022

—

—

2024

Engine:

Drive Unit:

—

Equipped with (RPO
S8L)

2023

Equipped with (RPOs
S8L, P79)

2024

Equipped with (RPOs
S8L, P79, P80, P8L,
S80)

Involved Region or Country

U.S. Dealers ONLY

Condition

Some customers may comment on the Malfunction Indicator Lamp (MIL) illuminated on the Driver
Information Center (DIC).
Technicians may find one or more of the following DTCs set.

Cause

•
•
•
•
•

P31A0 - Drive Unit Fluid Pump Control Circuit

•

P31A5 - Drive Unit Fluid Pump Feedback Signal Circuit Low

P31A1 - Drive Unit Fluid Pump Control Circuit High
P31A2 - Drive Unit Fluid Pump Control Circuit Low
P31A3 - Drive Unit Fluid Pump Performance
P31A4 - Drive Unit Fluid Pump Feedback Signal Circuit High

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.

Correction
Important: SThis technical service bulletin (TSB) can only be completed by certified repair facilities who have met all specific training, tool and
equipment requirements pertaining to the vehicle Brand and Model serviced. Repairs must be performed by a technician who has successfully
completed the required training.
Important: This technical service bulletin (TSB) can only be completed by BrightDrop dealers or BrightDrop certified repair facilities who have
met all BrightDrop specific training, tool and equipment requirements. Repairs must be performed by a technician who has successfully
completed the required training.
If you encounter a vehicle with the above concern, DO NOT perform any diagnostic steps. Contact GM Technical Assistance via DCM to start a case and
reference this PIE0746. A FSE will be dispatched for this vehicle. After starting a TAC Case, perform the following steps and contact the engineer listed below
with your findings.

Contact Information
1

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

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

8486298*

Engineering Information - (MIL) Illuminated on (DIC), Multiple DTCs Set

1.2 Hrs.

*This is a unique Labor Operation for bulletin use only.

Version

1

Modified

Released May 08, 2023

2