#20-NA-155: Service Engine Soon Message at Start Up or Shortly after Start Up - (Sep 10, 2020)
Subject:  Service Engine Soon Message at Start Up or Shortly after Start Up


This bulletin replaces PIT5735C. Please discard all copies of PIT5735.


Brand:

Model:

Model Year:

VIN:

Engine:

Transmission:

from

to

from

to

Cadillac

CT6

2019

2020

with LSY/LTA

All

XT5

2019

2019

LSY

XT6

2020

2020

Chevrolet

Blazer

2019

2020

LSY

Silverado 1500 (New Model)

2019

2019

Silverado 1500

2020

2020

GMC

Acadia

2019

2020

LSY

Sierra 1500 (New Model)

2019

2019

Sierra 1500

2020

2020

Involved Region or Country

North America, Middle East, Chile, Paraguay, Thailand, Russia, Israel, Palestine, Columbia, Ecuador, Peru, Japan, S. Korea, Australia and New Zealand.

Condition

Some customers may comment on a Service Engine Soon (SES) Malfunction Indicator Lamp (MIL) illuminated in the Driver Information Center (DIC) at start up or shortly after start-up.

When checking for DTCs, the Engine Control Module (ECM) will set P25A2 indicating that the BSCM (Brake System Control Module) has set DTCs. The BSCM will have set any combination of multiples of the following communication DTCs. DTCs can be set current or in history.

Technicians may find the following DTCs set:

  • P25A2
  • U0422
  • U0420
  • U0151
  • U0159
  • U0146
  • U0140
  • U0132
  • U0131
  • U0114
  • U0102
  • U0101
  • U0100
  • U0074
  • U0073
  • U023A
  • U026A

Cause

The cause of the condition may be due to a software anomaly.

For these U-codes, the BSCM may detect vehicle motion after driver’s foot is released from the brake pedal and parking pawl engaged. If motion is detected within 5 seconds prior to stoppage of CAN communications, after engine shutdown, the BSCM will re-enable its CAN bus communications and search for messages from the CAN bus. When messages are not detected, the BSCM will set U-code DTCs and may cause the P25A2 from the ECM to set.

Correction

Reprogram the Brake System Control Module (BSCM) with the latest update.

Service Procedure

Caution: Before downloading the update files, be sure the computer is connected to the internet through a network cable (hardwired). DO NOT DOWNLOAD or install the files wirelessly. If there is an interruption during programming, programming failure or control module damage may occur.

Note: Carefully read and follow the instructions below.

  • Ensure the programming tool is equipped with the latest software and is securely connected to the data link connector. If there is an interruption during programming, programming failure or control module damage may occur.
  • Stable battery voltage is critical during programming. Any fluctuation, spiking, over voltage or loss of voltage will interrupt programming. Install a GM Authorized Programming Support Tool to maintain system voltage. Refer to www.gmdesolutions.com for further information.  If not available, connect a fully charged 12 V jumper or booster pack disconnected from the AC voltage supply. DO NOT connect a battery charger.
  • Turn OFF or disable systems that may put a load on the vehicles battery such as; interior lights, exterior lights (including daytime running lights), HVAC, radio, etc.
  • Clear DTCs after programming is complete. Clearing powertrain DTCs will set the Inspection/Maintenance (I/M) system status indicators to NO.
Object Id: 5644477 Click here for detailed picture of the image.


Object Id: 5431207 Click here for detailed picture of the image.

Important: Techline Connect and TIS2WEB screens shown above.

Important: If the Same Calibration/Software Warning is noted on the TLC or SPS Summary screen, select OK and follow screen instructions. After a successful programming event, the WCC is located in the Service Programming System dialogue box of the SPS Summary screen. No further action is required. Refer to the Warranty section of the bulletin.

Important: When programming a module in GM’s new Vehicle Intelligence Platform, or VIP, the power mode (ignition) needs to be off or errors may occur. This involves the 2020 Chevrolet Corvette, Cadillac CT5 and CT4, as well as the upcoming full-size Chevrolet, GMC, Cadillac SUVs and Buick Envision. Serial Data Message Authentication also needs to have the ignition off.

Warranty Information

For vehicles repaired under the Bumper-to-Bumper coverage (Canada Base Warranty coverage), use the following labor operation. Reference the Applicable Warranties section of Investigate Vehicle History (IVH) for coverage information.

Labor Operation

Description

Labor Time

2886978*

K160 Brake System Control Module Reprogramming with SPS

0.3 hr

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

Important: *To avoid warranty transaction rejections, carefully read and follow the instructions below:

  • The SPS Warranty Claim Code must be accurately entered in the “SPS Warranty Claim Code” field of the transaction.
  • When more than one Warranty Claim Code is generated for a programming event, it is required to document all Warranty Claim Codes in the “Correction” field on the job card. Dealers must also enter one of the codes in the “SPS Warranty Claim Code” field of the transaction, otherwise the transaction will reject. It is best practice to enter the FINAL code provided by SPS/SPS2.

Warranty Claim Code Information Retrieval

If the SPS Warranty Claim Code was not recorded on the Job Card, the code can be retrieved in the SPS system as follows:

The VIN, Warranty Claim Code and Date/Time will be listed on a roster of recent programming events. If the code is retrievable, dealers should resubmit the transaction making sure to include the code in the SPS Warranty Claim Code field.

Version

3

Modified

Released August 05, 2020

Revised August 11, 2020 – Reworded vehicle models and updated labor operation

Revised September 10, 2020 – Added Cadillac CT6, XT5, XT6, Chevrolet Blazer and GMC Acadia, Updated Cause Section and Service Procedure Programming Information.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer".  They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle.  Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely.  If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition.  See your GM dealer for information on whether your vehicle may benefit from the information.

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