NHTSA ID Number: 11011711
Manufacturer Communication Number: 21-NA-130
TSB/Document Date: 2024-12-10
Summary
This service bulletin provides a repair procedure to correct a customer concern of Malfunction Indicator Lamp (MIL) Illuminated, DTC P31E8, P31DB, P31D4 and/or P31E2 Set.
Bulletin No.: 21-NA-130
Service Bulletin
Date: November, 2024
TECHNICAL
Subject:
Brand:
Malfunction Indicator Lamp (MIL) Illuminated, DTC P31E8, P31DB, P31D4
and/or P31E2 Set
Model:
CT4
CT5
Involved Region or Country
Condition
Model Year:
VIN:
from
to
from
to
2020
2021
—
—
2.7L (L3B),
3.0L (LGY)
—
North America, Middle East, Israel, Palestine, Japan, Cadillac
Korea (South Korea)
Some customers may comment that the MIL is illuminated.
Some technicians may find one or more of the following DTCs set in the Engine Control
Module (ECM):
• P31D4: Exhaust Flow Control Valve - Position Signal Exceeds Upper Limit — Bank 1
• P31DB: Exhaust Flow Control Valve Stuck Open — Bank 1
• P31E2: Exhaust Flow Control Valve - Position Signal Exceeds Upper Limit Bank 2
• P31E8: Exhaust Flow Control Valve Stuck Open Bank 2
Cause
This condition may be caused by old firmware or fail-safe spring failure within exhaust
valve actuator.
Correction
Replace both exhaust valve actuators if the above DTCs are found.
Important: Service agents must comply with all International, Federal, State, Provincial, and/or Local laws
applicable to the activities it performs under this bulletin, including but not limited to handling, deploying,
preparing, classifying, packaging, marking, labeling, and shipping dangerous goods. In the event of a
conflict between the procedures set forth in this bulletin and the laws that apply to your dealership, you
must follow those applicable laws.
Service Procedure
Refer to Exhaust Control Valve Actuator Replacement in SI.
General Step by Step Instruction – Hardware Install
1. Verify that the actuator is not connected or powered.
Copyright 2024 General Motors. All Rights Reserved.
Page 2
November, 2024
Bulletin No.: 21-NA-130
5779070
2. Attach the spring to loose un-powered actuator (1) (note the orientation of the spring).
⇒
Verify the spring clip is centered and firmly seated.
⇒
The tab in the actuator should be pointed away (3) from the motor (2).
5779060
3. Manually turn the valve bearing on the exhaust side to its closed position. Note the turning direction (1).
4. While forcing the valve bearing to its closed position, position a small flat-headed screwdriver or pick tool to
keep the valve in its closed position (3).
Bulletin No.: 21-NA-130
November, 2024
Page 3
5779088
5. Install the un-powered actuator as square as possible to its installation bolts.
6. Press against the actuator body while installing the bolts.
Tighten
Tighten the bolts to 10 N.m (88.5 lb in).
General Step by Step Instruction – Programming the Exhaust Flow Control Valve
Note: For further information, refer to Exhaust Flow Control Valve Learn in SI.
1. Ignition » On / Vehicle » In Service Mode
2. Select: Module Diagnostics
3. Select: Engine Control Module
4. Select: Configuration/Reset Functions
5. Select: Learn Functions Reset Functions
6. Select: Exhaust Control Valve
Note: The scan tool does not display the learn/reset status.
7. Follow the instructions on the scan tool. The procedure will complete within 10 seconds.
Parts Information
Causal
Part
Description
Part
Number
Qty
X
ACTUATOR,
EXH CONT VLV
85120344
2
Warranty Information
For vehicles repaired under warranty, use:
Labor
Operation
4051800
Description
Labor Time
Exhaust Control Valve
Actuator Replacement
Use
Published
Labor
Operation
Time
Page 4
November, 2024
Bulletin No.: 21-NA-130
Version
2
Modified
Released May 28, 2021
November 07, 2024 – Added the Important statement and updated the part quantity to
2 in Parts Information section.
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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TSB/Document ID: 21-NA-130
Replacement Service Bulletin Number:
MFR Communication Date: 2024-11-08
MFR Internal Campaign ID/Software Version:
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: ENGINE
MFR Component System:
MFR Component Subsystem:
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