21-NA-220

Bulletin No.:
Service Bulletin
Date:
21-NA-220
September, 2023
TECHNICAL
Subject:
Loss of Power, Malfunction Indicator Lamp (MIL) Illuminated, Gauges Inoperative and/
or Multiple Warning Lights/Messages Displayed on Driver Information Center (DIC) –
Multiple DTCs Set
Brand:
Model:
Chevrolet
Malibu
Model Year:
VIN:
from
to
from
to
2016
2024
—
—
Engine:
Transmission:
1.5L
Turbo (LFV)
—
Involved Region or Country
North America, Israel, Palestine
Condition
Some customers may comment on one or more of the following conditions:
• Loss of power
• MIL illuminated
• Gauges dropping out
• Multiple warning lights and/or messages
Technicians may find one or more of the following DTCs stored in the Engine Control
Module (ECM):
– P0700, P150C, P15FD, P2544, P308D, U0073, U0101, U0129, U0140, U0146,
U183A, U18D5, U18D7, U2413, U0121, U0100, U0401, U0131
Cause
This condition may be caused by high resistance on the HSCAN BUS circuits 2500/2501
between the Electronic Brake Control Module (EBCM) and the Power Steering Control
Module (PSCM).
Copyright 2023 General Motors LLC. All Rights Reserved.
Page 2
September, 2023
Bulletin No.: 21-NA-220
2220548
Correction
2339640
With the battery disconnected, verify the resistance of the HSBUS circuits across 2500,
2501 splitting the circuit at the X115 electrical connector. Refer to Master Electrical
Component List in SI. Looking for any unwanted resistance (ex. 126.7 or something other
than in the range of 120 ohms). If stray resistance is traced down to one of the module
connector terminals, verify terminal tension and ensure there is no damage to the
terminal. If the terminal is good, then apply dielectric grease to the terminals.
If the terminals are damaged or have poor terminal tension, replace with terminated leads
at the suspect module connector and apply dielectric grease to the connector.
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
1. Disconnect the battery.
2. Disconnect the X115 engine harness electrical
connector.
⇒ Verify the resistance of the HSBUS circuits
across 2500, 2501 splitting the circuit at the
X115 electrical connector.
3. Remove the radiator surge tank fastener.
4. Disconnect the engine wiring harness clip from the
surge tank.
5. Reposition surge tank aside to gain access to
the EBCM.
Bulletin No.: 21-NA-220
September, 2023
Page 3
13. Install the surge tank fastener. Refer to Fastener
Specifications in SI.
14. Raise the vehicle.
5905953
6. Disconnect the K17 EBCM electrical connector.
5905956
15. Disconnect the K43 PSCM electrical connector.
3960473
7. Inspect for terminal tension/damage at the wiring
harness for circuits 2500/2501.
⇒ If improper terminal tension is found, replace
terminals with terminated leads per SI.
8. Verify the resistance of the HSBUS circuits across
2500, 2501.
9. Add dielectric grease to the terminals.
10. Connect the EBCM connector.
11. Reposition the surge tank.
12. Install the wiring harness clip onto the surge tank.
2586629
16. Inspect for terminal tension/damage at the wiring
harness for circuits 2500/2501.
⇒ If improper terminal tension is found, replace
terminals with terminated leads per SI.
17. Verify the resistance of the HSBUS circuits across
2500, 2501.
18. Add dielectric grease to the terminals.
19. Connect the PSCM electrical connector.
Page 4
September, 2023
Bulletin No.: 21-NA-220
20. Lower the vehicle.
21. Connect the X115 engine harness electrical
connector.
22. Connect the battery.
Parts Information
Causal
Part
N/A
Description
ACDelco
Dielectric
Lubricant*
Part
Number
12377900
(U.S.)
10953529
(Canada)
Qty
1
*There is enough material to do additional vehicles. Store
the remaining material for future use.
Warranty Information
Note: Only use the Labor Operation number that
coincides with the repair performed.
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
Terminal Testing/Inspection
and Dielectric Lubricant
Application
1.0 hr
5486258*
Add
EBCM Terminal Repair
0.5 hr
Add
PSCM Terminal Repair
0.5 hr
*This is a unique Labor Operation for bulletin use only.
Version
4
Modified
Released October 08, 2021
Revised November 05, 2021 – Added DTC U0073 in the Condition section and Israel,
Palestine to the Involved Region or Country section.
Revised September 02, 2022 – Added 2016–2018 Model Years and the Important
statement above the Service Procedure.
Revised September 08, 2023 – Added the 2023–2024 Model Years.
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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