Service Bulletin

Bulletin No.:

18-NA-114

Date:

May, 2022

TECHNICAL
Subject:

Intermittent Service All Wheel Drive (AWD)/Service Stability Messages and/or Low Oil
Pressure Shut Off Engine Message Displayed in Driver Information Center (DIC),
Erratic Speedometer Readings, No Crank, Malfunction Indicator Lamp (MIL)
Illuminated - DTC P0641, P2535, U0073, U0100, U0101, U0121, U0131, U0136 and/or
U1814 Set

Brand:

Model:

Chevrolet

Trax

Model Year:

VIN:

from

to

from

to

2018

2020

—

—

Involved Region or Country

Engine:

Transmission:

1.4L (LUV)

—

North America, Israel, Argentina, Colombia, Ecuador, Paraguay, Uruguay
Note: Not all of the effects or driver notifications listed have been experienced. However,
the different effects and driver notifications may be caused by one of the wires in the
wiring harness being chafed or cut. Components on different lines in the list below are in
different circuits. Due to the cause of the condition, and the positions of the wires in the
harness, it is unlikely that more than one circuit and/or fuse will be affected by the
condition.

Condition

Some customers may comment on one or more of the following conditions:
• MIL is illuminated
• Service AWD message displayed on DIC
• Service Stability message displayed on DIC
• Low Oil Pressure Shut Off Engine message displayed on DIC
• Erratic speedometer readings
• No crank
Technicians may find one or more of the following DTCs set:
• P0641: 5V Reference 1 Circuit set in the Engine Control Module (ECM)
• P2535: Ignition On/Start Switch Circuit High Voltage
• U0073: Control Module Communication Bus A Offset in the ECM or TCM
• U0100: Multiple state of health messages, set in the ECM or TCM
• U0101: Lost Communication with Transmission Control Module
• U0121: Lost Communication with Electronic Brake Control Module
• U0131: Lost Communication with Power Steering Control Module
• U0136: Lost Communication with Differential Control Module - Rear
• U1814: Powertrain Wake-Up Communication Circuit
Technicians may also find fuse F18UA open.
Note: This is a multi-wire bundled harness and, depending on which wire is damaged,
can set a variety of DTCs.

Cause

This condition may be caused by the engine harness chaffing against the G100
Ground stud.
This condition may be caused by damage to the engine harness near the X112
connector.

⇒ Inspect G103 (refer to bulletin 19-NA-068)

Copyright 2022 General Motors LLC. All Rights Reserved.

Page 2

May, 2022

Bulletin No.: 18-NA-114

Correction

5040432

If the above condition has been validated, inspection of the engine wiring harness must
be done.
1. With a suitable light, inspect the wiring harness point of contact at the G100
ground stud.

⇒ For stud location, refer to Document ID#: 4708510 in SI.
2. Repair the harness as needed.

⇒ Refer to Wire to Wire Repair in SI.

Bulletin No.: 18-NA-114

May, 2022

Page 3

5040564

3. Using Woven Polyester Electrical Tape (PET), tape all the contact points of the
engine harness ensuring that the tape is applied in a double layer.
4. Reposition the engine harness so that it cannot contact the ground stud.

⇒ If required, replace the blown fuse in regards to repair performed on the
engine harness.

Page 4

May, 2022

Bulletin No.: 18-NA-114

6056400

5. Inspect the engine harness (1) in the engine compartment located on the left side of
the engine near the X112 electrical connector (2):
5.1. Remove the battery. Refer to Battery Replacement in SI.
5.2. Inspect wiring approximately 76 mm (3 in) from x112 connector for any signs
of damage.
5.3. Repair the harness as needed. Refer to Wire to Wire Repair in SI.
5.4. Install the battery. Refer to Battery Replacement in SI.

6056401

Inspect G103 (refer to bulletin 19-NA-068)

Bulletin No.: 18-NA-114

May, 2022

Page 5

Parts Information
No parts are required for this repair.

Warranty Information
For vehicles repaired under warranty, use:
Labor
Operation

5430902

Description

Labor Time

Wire-to-Wire Repair

Use
Published
Labor
Operation
Time

Version

9

Modified

Released April 12, 2018
May 4, 2018 – Changed the Engine RPO and added Additional Keywords.
June 12, 2018 – Updated the Subject and Condition sections to add additional DTCs and
conditions.
March 28, 2019 – Added the 2019 Model Year.
February 3, 2020 – Added the 2020 Model Year.
October 9, 2020 – Added DTC U1814 to Subject and Condition section and updated the
Involved Region or Country section.
October 23, 2020 – Added Low Oil Pressure Shut Off Engine Message information to
Subject and Condition section.
July 21, 2021 – Added No Crank condition and DTC P2535 to Subject and Condition
sections and added Open Fuse F18UA to Condition section.
May 6, 2022 – Updated the Cause and Correction sections.

Additional SI Keywords: 5V ref, B111B, Turbo boost
sensor

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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