21NA130

Service Bulletin
Bulletin No.:
21-NA-130
Date:
June, 2021
TECHNICAL
Subject:
Brand:
Cadillac
Malfunction Indicator Lamp (MIL) Illuminated, DTC P31E8, P31DB, P31D4 and/or
P31E2 Set
Model:
CT4
CT5
Model Year:
VIN:
from
to
from
to
2020
2021
—
—
Engine:
Transmission:
2.7L (L3B),
3.0L (LGY)
—
Involved Region or Country
North America, Middle East, Israel, Palestine, Japan, Cadillac Korea (South Korea)
Condition
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.
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.
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).
Copyright 2021 General Motors LLC. All Rights Reserved.
Page 2
June, 2021
Bulletin No.: 21-NA-130
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 Y (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 (Document ID# 5522032) in SI.
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).
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 s.
Parts Information
Causal
Part
Description
Part
Number
Qty
X
ACTUATOR, EXH
CONT VLV
85120344
1
Warranty Information
For vehicles repaired under warranty, use:
Labor
Operation
4051800
Description
Labor Time
Exhaust Control Valve
Actuator Replacement
Use Published
Labor
Operation Time
5779088
Version
1
Modified
Released May 28, 2021
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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