Service Bulletin

Bulletin No.:

18-NA-083

Date:

May, 2019

TECHNICAL
Subject:

Service Transmission Message Displayed on Driver Information Center (DIC),
Malfunction Indicator Lamp (MIL) Illuminated - DTCs P0722, P0729, P0730, P0731,
P0732, P0733, P0734, P0735, P073D, P073E, P07A2, P07E4, P07E5 and/or P1769 Set
Model Year:

VIN:

Brand:

Model:

Buick

LaCrosse

2017

2017

Cadillac

XT5

2017

2019

from

to

from

to

Engine:

Transmission:
Automatic
(MRC)

Involved Region or Country

North America, Europe, South Korea, China, Middle East

Condition

Some customers may comment on the following conditions:
• MIL is illuminated
• Service Transmission message is displayed on the DIC
Some technicians may find one or more of the following DTCs set in history or current:
• P0722: Output Speed Sensor Circuit No Signal
• P0729: 6th Gear Ratio Incorrect
• P0730: Gear Ratio Incorrect
• P0731: 1st Gear Ratio Incorrect
• P0732: 2nd Gear Ratio Incorrect
• P0733: 3rd Gear Ratio Incorrect
• P0734: 4th Gear Ratio Incorrect
• P0735: 5th Gear Ratio Incorrect
• P073D: Unable to Engage Neutral set in the Chassis Control Module
• P073E: Unable to Engage Reverse set in the Chassis Control Module
• P07A2: Transmission Clutch 1 Performance
• 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
Transmission Range Control Module (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 below.

Service Procedure
1. Inspect the transmission fluid level. Refer to
Transmission Fluid Level and Condition Check
in SI.
• If the automatic transmission fluid is dark and
an overheated odor, internal wear of the
automatic transmission is suspected and that
should be addressed. Refer to SI for further
diagnosis.
• If the automatic transmission fluid is OK,
proceed to the next step.
Copyright 2019 General Motors LLC. All Rights Reserved.

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

Page 2

May, 2019

Bulletin No.: 18-NA-083

4. For XT5 vehicles:

4290995

4.1. Without disconnecting the electrical
connectors, detach the engine control module
(ECM) from the bracket assembly and
position aside.
4.2. Remove the ECM bracket (2).
4.3. Proceed to step 5.

Bulletin No.: 18-NA-083

May, 2019

Page 3

For LaCrosse vehicles:

4451509

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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May, 2019

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. Tighten the automatic transmission range selector
actuator hardware module bolts.
⇒ Refer to Fastener Specifications in SI.
9. Perform the TRCM learn procedure (Not for new
modules). Refer to Transmission Range Control
Module Learn Procedure in SI.
• 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.
⇒ Tighten the fasteners to specifications. Refer to
Fastener Specifications in SI.

Bulletin No.: 18-NA-083

May, 2019

Page 5

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
8480728*

Description

Labor Time

Automatic Transmission
Range Selector Actuator
Hardware Module
Adjustment

0.5 hr (XT5)
1.0 hr
(LaCrosse)

*This is a unique Labor Operation for Bulletin use only.

Version

2

Modified

Released March 15, 2018
May 22, 2019 – Added additional DTCs, 2019 to XT5 model and steps to check fluid
condition at the beginning of the Service Procedure.

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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