File in Section:
Bulletin No.:

Service Bulletin

Date:

18-NA-063
March, 2018

TECHNICAL
Subject:

Multiple Electrical Issues, Dead Battery, Start/Stop Inoperative, Instrument Cluster and
Switch Backlighting Remain Illuminated

Brand:

Model:

Cadillac

XT5

GMC

Acadia
(VIN N)

Model Year:

VIN:

from

to

2017

2017

Involved Region or Country

from

Engine:

Transmission:

All

All

to

North America, N.A. Export Regions

Additional Options (RPOs)

Condition

Some customers may comment on seeing any of multiple electrical issues, including but
not limited to:
• Dead battery
• Start/Stop inoperative
• Instrument cluster and switch backlighting remain illuminated

Cause

4977973

The cause of the condition may be that the wrong bulbs may have been installed in the
backup lamps. Incandescent bulbs (example shown above) should have been used, but
LED’s may have been incorrectly installed in their place.
Note: The BCM evaluates the Reverse Lamp circuit to determine bulb outages by
applying and monitoring a low voltage signal. Because LED lamps have different
electrical properties than Incandescent bulbs, the circuit does not operate as expected.
The BCM is calibrated for incandescent lamps and may stay awake after key off, if LED's
are used. The BCM will continuously monitor the circuit, resulting in the symptoms
identified above.

Copyright 2018 General Motors LLC. All Rights Reserved.

Page 2

March, 2018

Bulletin No.: 18-NA-063

Correction

4977978

On vehicles that exhibit the above conditions or other electrical abnormalities, check the
bulbs in the back up lamp locations.
• If the bulbs are found to be LED (1), the incorrect bulbs have been used and they
need to be replaced with Incandescent bulbs.
• If the bulbs are found to be the proper incandescent bulbs (2), refer to SI for further
diagnostic recommendations.
For backup bulb replacement, refer to the appropriate Backup Bulb Replacement
procedure below.

For Cadillac XT5 Models

For GMC Acadia (VIN N) Models

4977982

1. Locate the backup lamp assembly underneath the
rear fascia.
2. Remove the bulb from the lamp assembly by
turning it counterclockwise and pulling straight out.
3. Remove the bulb and replace.
4. Reverse Steps 2 and 3 for assembly.

4977986

Refer to Backup Bulb Replacement in SI.

Parts Information
Use the vehicle identification number (VIN), SI, and the
GM Electronic Parts Catalog to determine the proper
incandescent bulbs to order.

Bulletin No.: 18-NA-063

March, 2018

Page 3

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

Description

Labor Time

2043260

Backup Lamp Bulb Replacement

Use Published Labor
Operation Time

Version

1

Modified

Released February 26, 2018

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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