File in Section:
Bulletin No.:

Service Bulletin

Date:

18-NA-083
March, 2018

TECHNICAL
Subject:

Service Transmission Message Displayed On Drivers Information Center (DIC),
Malfunction Indicator Lamp Illuminated (MIL) - DTCs P073D, P073E, P07E4, P07E5, and/
or P1769 Set

Brand:

Model:

Buick
Cadillac

Model Year:

VIN:

from

to

Lacrosse

2017

2017

XT5

2017

2018

from

Engine:

Transmission:

to
MRC

Involved Region or Country

North America, Europe, Asia and Middle East

Condition

Some customers may comment that:
• MIL is illuminated
• Service Transmission message is displayed on the DIC
Some technicians may find one or more of the following DTC’s set in history or current:
• P073D: Unable to Engage Neutral set in the Chassis Control Module
• P073E: Unable to Engage Reverse set in the Chassis Control Module
• P07E4: Unable to Engage Park set in the Chassis Control Module
• P07E5: Unable to Engage Drive set in the Chassis Control Module
• P1769: Transmission Range Sensor TRCM Correlation set in the Chassis Control
Module

Cause

This condition may be caused by the misalignment of the coupler between the TRCM and
the Transmission.

Correction

If the above DTCs are set in history or current during the service evaluation, the TRCM
needs to be re-centered by following the service procedure in this bulletin.

Service Procedure
Note: To perform the transmission learn procedure, it
is recommended that the transmission is warmed up
between 50F° to 104F° (10C° to 40C°).
1. Apply the parking brake and place the
transmission control assembly in the Park position.
2. Perform the Backup Park Lock Actuator Disarming
procedure. Refer to Backup Park Lock Actuator
Disarming in SI.

Copyright 2018 General Motors LLC. All Rights Reserved.

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March, 2018

Bulletin No.: 18-NA-083

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3. For the XT5 vehicles:
3.1. Without disconnecting the electrical
connectors, detach the ECM from the bracket
assembly and position aside.
3.2. Remove the ECM bracket (2).
3.3. Proceed to step 5.

Bulletin No.: 18-NA-083

March, 2018

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4451509

4. For the Lacrosse vehicles:
4.1. Remove the Air Cleaner Housing assembly.
Refer to Air Cleaner Assembly Replacement
in SI.
4.2. Remove the bolt that secures the intake air
duct to the core support.
4.3. Remove the Air Cleaner Bracket (3).

4286543

Note: For the XT5, the actuator module bolt located
under the battery tray can be accessed without
removing the battery tray.
5. Loosen (approximately ¼ in.) the automatic
transmission range selector actuator hardware
module bolts (2).

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March, 2018

Bulletin No.: 18-NA-083

4997865

Note: The turning radius of the module will be very
slight when centering.
6. Rotate the automatic transmission range selector
actuator hardware module;
6.1. Rotate clockwise until right lock position,
shown with a blue line.
6.2. Rotate counterclockwise until left lock
position, shown with a green line.
6.3. Rotate clockwise until it is centered between
both full lock positions, shown with a red line.
7. While holding the automatic transmission range
selector actuator hardware module with one hand,
tighten hardware module bolts to prevent the
actuator from moving from the center position.
8. Torque the automatic transmission range selector
actuator hardware module bolts.
⇒ Refer to Fastener Specifications in SI.

9. Perform the TRCM. Refer to Transmission Range
Control Module Learn Procedure (Not for new
modules).
• If the test fails, re-adjust the module and retest.
• If the test fails after re-adjusting the module,
refer to SI for further diagnostics on the
code set.
• If the test passes, proceed with procedure.
10. Install previously removed components.
⇒ Torque the fasteners to specifications. Refer to
Fastener Specifications in SI.

Parts Information
No parts are required for this repair.

Warranty Information
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

8480728*

Automatic Transmission Range Selector Actuator Hardware
Module Adjustment

0.5 hr (XT5)

*This is a unique Labor Operation for Bulletin use only. It will not be published in the Labor Time Guide.

1.0 hr (Lacrosse

Bulletin No.: 18-NA-083

March, 2018

Version

1

Modified

Released March 15, 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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