Transmission Neutral Service Mode

Transmission Neutral Service Mode

2021-2022 CT4, CT5, Escalade, Tahoe, Suburban and Yukon models equipped with the 10L60 10-speed automatic transmission (RPO MQA) or 10L80 10-speed automatic transmission (RPO MHS, MQC) feature an internal Electronic […]

November 30, 2021
TechLine Connect Software Update Adds New Direct Launch Programming Functionality

TechLine Connect Software Update Adds New Direct Launch Programming Functionality

The November Techline Connect (TLC) software update introduces “Direct Launch” capability to simplify any service programming related to Field Actions. Direct Launch functionality is designed to improve first time quality […]

November 23, 2021
Poor Splice Connection in 1.2L Engine Wiring Harness

Poor Splice Connection in 1.2L Engine Wiring Harness

A poor splice connection in the engine wiring harness on some 2020-2021 Trailblazer and Encore GX models equipped with the 1.2L engine (RPO LIH) may result in an illuminated Check […]

November 23, 2021
GDS2 Update Includes New MDI Tool Selection Window

GDS2 Update Includes New MDI Tool Selection Window

The latest GDS2 core update release (v22.2.05000) includes an update to the J2534 Wrapper, or MDI tool selection window. Since the MDI no longer receives updates to its core software, […]

November 23, 2021
New Dealer Infrastructure & Security Guidelines Released for 2022

New Dealer Infrastructure & Security Guidelines Released for 2022

GM has recently released new Dealer Infrastructure & Security Guidelines (DISG) for 2022. The new guidelines outline the dealership technology needed to ensure reliable data communications for all dealers, including […]

November 23, 2021
Driver’s Outside Rearview Mirror Appearance

Driver’s Outside Rearview Mirror Appearance

The driver’s outside rearview mirror on some 2020-2022 Corvettes may have poor operation and appearance, including numerous lines shown in the mirror and a dim reflection at all times. (Fig. […]

November 23, 2021
DTCs Set Due to Transmission Fluid Pump Fuse

DTCs Set Due to Transmission Fluid Pump Fuse

automatic transmission (RPO MRG) may have an illuminated Check Engine MIL and/or the engine stop/start feature may be inoperative. DTC P2796 (Auxiliary Transmission Fluid Pump Control Circuit) and DTC P2798 (Auxiliary […]

November 23, 2021
Charge Air Cooler Icing During Extreme Cold Weather

Charge Air Cooler Icing During Extreme Cold Weather

When driving in extreme cold weather conditions (0°F or less / -18°C or less), a winter grille cover should be installed on 2019-2022 XT4 models equipped with the 2.0L turbo […]

November 23, 2021
Driver Assistance Systems Disabled due to Incorrect Tire Size

Driver Assistance Systems Disabled due to Incorrect Tire Size

The Lane Keep Assist and Forward Collison Alert systems may become inoperative on some 2020-2022 Encore GX and 2021-2022 Trailblazer models. While driving, the Lane Keep Assist and vehicle detection […]

November 23, 2021
GM Service Know-How Emerging Issues

GM Service Know-How Emerging Issues

The monthly GM Service Know-How Emerging Issues seminars provide service/technical information on current issues and GM certified repairs. The latest service topics from GM Brand Quality and Engineering covered in […]

November 23, 2021
Engine Wiring Harness Chafing Repairs

Engine Wiring Harness Chafing Repairs

Several engine wiring harness chafing conditions may be found on some 2019-2021 Silverado and Sierra models as well as some 2021 Tahoe, Suburban, Yukon and Escalade models. Depending on the […]

October 30, 2021
Insufficient Heating Performance Due to Exhaust Manifold Outlet Pipe

Insufficient Heating Performance Due to Exhaust Manifold Outlet Pipe

Some 2020-2021 Encore GX and Trailblazer models equipped with the 1.3L turbo engine (RPO L3T) may have insufficient heat or no heat in the cabin after driving for several minutes. […]

October 30, 2021
HVAC Temperature Actuator Operation at Low Temperatures

HVAC Temperature Actuator Operation at Low Temperatures

The Check Engine MIL may be illuminated on some 2020-2021 CT4 models equipped with the 2.0L engine (RPO LSY) or 2.7L engine (RPO L3B) and some 2020-2021 CT5 models equipped […]

October 30, 2021
CSMT Mobile App Update and Job Aids

CSMT Mobile App Update and Job Aids

New resources are now available to U.S. dealerships for help with submitting or reworking warranty approval requests using the Pre-Repair Authorization (PRA) application (Fig. 13) in the Certified Service Mobile […]

October 30, 2021
Service Leveling System Message Due to Aftermarket Modifications

Service Leveling System Message Due to Aftermarket Modifications

A Service Leveling System message or Speed Limited message on the Driver Information Center (DIC) on some 2021 Tahoe, Suburban, Yukon and Escalade models may be due to aftermarket modifications. […]

October 30, 2021
Dipstick Tube O-Ring Oil Leak

Dipstick Tube O-Ring Oil Leak

When diagnosing engine oil leaks on 2019-2022 Silverado, Sierra; and 2020-2022 CT4-V models equipped with the 2.7: turbocharged 4-cylinder engine (RPO L3B) (Fig. 22), inspect the dipstick tube (indicator tube) […]

October 30, 2021
Latest GM Global Electronic Parts Catalog Release Identifies Single Use Parts, Adds Links to SI and Labor Codes

Latest GM Global Electronic Parts Catalog Release Identifies Single Use Parts, Adds Links to SI and Labor Codes

The latest update to the GM Global Electronic Parts Catalog (EPC) features additional identifiers for single use parts along with a number of links to related Service Information procedures and […]

October 15, 2021
Inspecting High Voltage Insulation Gloves

Inspecting High Voltage Insulation Gloves

When working on any high voltage system on a GM vehicle, certified and tested high voltage insulation gloves must be worn. (Fig. 9) Certified and up-to-date Class “0” insulation gloves […]

October 15, 2021
Warning Lamps Illuminate During Vehicle Turns

Warning Lamps Illuminate During Vehicle Turns

Some 2020 Trax models may have airbag, theft (security) and tire pressure warning lamps that turn on/off along with an illuminated Check Engine lamp during vehicle turns. DTCs U0078 (Control […]

October 15, 2021
Squeak Sound When Turning Steering Wheel

Squeak Sound When Turning Steering Wheel

A squeak sound may be heard from the steering system when making turns in either direction on some 2017-2022 Bolt EV and 2022 Bolt EUV models. The sound may be […]

October 15, 2021