23-NA-210

Bulletin No.:
Service Bulletin
Date:
23-NA-210
December, 2023
TECHNICAL
Subject:
Malfunction Indicator Lamp (MIL) Illuminated - DTCs P18AE and/or P0700 Set
Attention: This bulletin applies to vehicles with mileage of 5000 miles (8046 km) or less.
Brand:
Model:
Model Year:
from
to
VIN:
from
to
Engine:
Transmission:
CT4
Cadillac
CT5
Escalade Models
Chevrolet
Silverado 1500
GMC
Sierra 1500
Involved Region or Country
Condition
Correction
Copyright 2023 General Motors LLC. All Rights Reserved.
2023
2024
MHO, MHS,
MHU, MHX,
MQ2,
MQA, MQC
North America, Europe, Middle East, Israel, Palestine, Argentina (Mercosur), Brazil
(Mercosur), Bolivia (West), Chile (West), Colombia (West), Ecuador (West), Paraguay
(West), Peru (West), Uruguay (West), Japan, Thailand (ASEAN)
Some customers may comment on the MIL illuminated immediately after starting vehicle.
Some technicians may find DTC P18AE and/or P0700 set in the Transmission Control
Module (TCM).
Important: For vehicles with over 5000 miles (8046 km), follow the diagnostic path for
DTC P18AE.
Note: Only follow this diagnostic if only DTC P18AE has set along with DTC P0700.
Correct all other performance related DTC’s prior to following the diagnostics below.
1. Using GDS, clear the DTC.
2. Shut the engine off, exit the vehicle with the key fob or key and allow all vehicle
modules to power down.
3. Restart the vehicle and idle for 10 seconds.
4. Shift from Park to Drive, Drive to Reverse, Reverse to Park.
5. Shut the engine off, exit the vehicle with the key fob or key and allow all vehicle
modules to power down.
6. Restart the vehicle and idle for 10 seconds.
7. Check to see if P18AE or any other Transmission DTCs set.
• If no DTC’s are current, use the Labor Code listed below and return the vehicle back
to the customer
• If DTC P18AE has returned, replace the valve body. Refer to Control Valve Body
Replacement in SI.
• If any other Transmission DTC’s have set, follow published Service Information (SI)
Procedures.
Page 2
December, 2023
Bulletin No.: 23-NA-210
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.
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
8486388*
DTC P18AE Diagnostic Check
0.5 hr
*This is a unique Labor Operation for Bulletin use only.
Version
1
Modified
Released November 27, 2023
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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