Diagnostic Tips for Exhaust Charge DTCs
Several high-pressure exhaust charge DTCs may set on some 2019-2022 Silverado, Sierra; 2021-2022 Tahoe, Suburban, Escalade; and 2022 Yukon models equipped with the 5.3L engine (RPO L84) or 6.2L engine […]
EVAP System Leak Testing
Some 2021-2022 Encore and Trax models equipped with the 1.4L engine (RPO LE2) may have DTC P0442, (Evaporative Emission [EVAP] System Small Leak Detected) set in the ECM. The DTC […]
Rear Axle Moan During Turns
Some 2020-2022 CT4 and CT5 models equipped with the limited-slip differential (RPO G80) may have a moan sound during left or right turns. The condition may be caused by a […]
Exhaust Heat Shield Rattle
A rattle sound from under the vehicle while driving may be heard on some 2021-2023 Silverado 1500, Silverado 2500HD/3500HD, Tahoe, Suburban, Sierra 1500, Sierra 2500HD/3500HD, Yukon, Escalade; and 2022 Silverado […]
Residue on Liftgate Strut is not a Fluid Leak
Residue on the rear liftgate strut (Fig. 8) of some 2018-2020 Enclave, Traverse; 2020-2022 Acadia, XT5 and XT6 models is not a fluid leak that requires strut replacement. The residue […]
Cooling Fan Speed Too Low Condition
While fording a river with the 2022 HUMMER EV pickup (Fig. 11), an excessive amount of water may slow or stop the cooling fan from spinning, which may cause DTC […]
Cradle Brace Mounting Rattle
A rattle or clunk sound may be heard at the front of the vehicle on some 2017-2023 Acadia; 2018-2023 Traverse; 2019-2023 Blazer; and 2020-2023 XT5 models. The sound may seem […]
Diesel Exhaust Fluid Contamination in the Fuel System
Poor diesel engine performance conditions, such as hard starts, rough running or hesitations and low fuel pressure, may be the result of fuel system contamination. The most common sources of […]
New Components Available for Pre-Repair Authorization Using the CSMT App
Warranty replacement of a number of components, including wheels, seat covers and cushions and interior door trim, requires GM pre-authorization before repairs are made (U.S. and Canada). The Pre-Repair Authorization […]
Two Seal Designs Included in 10-Speed Transmission Auxiliary Pump Seal Kit
Replacing the control valve body on the 10-speed automatic transmission (RPO MHS, MHT, MHW, MHX, MQA, MQB, MQC, MQL) with the auto engine stop/start feature, available on 2019-2020 CT6; 2019-2022 […]
Front Heated Seat Malfunction After Collision Repairs
Heated seat operation may be inhibited on GM models equipped with the Global A electrical architecture if the vehicle was in a collision. If the front heated seats (Fig. 13) […]
Service Transmission Messages Require Engine Control Module Reprogramming
Some 2022 Bolt EV and Bolt EUV models (Fig. 16) may have a “Service Transmission, Unable to Shift” message or “Service Transmission Now, Unable to Shift Soon” message displayed on […]
New GM Global EPC Update Offers Email Function, Expanded Display of Parts and More
The July 2022 update to the GM Global Electronic Parts Catalog (EPC) includes a number of new features that add to the functionality of the EPC, making parts searches easier […]
Fuel Additives Impact on Fuel Quality
Various unproven products over the years have claimed to improve vehicle fuel economy. Many of these product benefits are based on unsubstantiated claims. In fact, the U.S. Federal Trade Commission […]
New 2022 Silverado 1500 and Sierra 1500 Boast Updated Looks, Advanced Features
The new 2022 Chevrolet Silverado 1500 (Fig. 9) and GMC Sierra 1500 offer a number of enhancements as part of a mid-year launch. The updated models feature new designs — […]
2023 LYRIQ TAC Action Center Now Open
The GM Technical Assistance Center, or TAC, (U.S.) has established an Action Center for the all-new 2023 Cadillac LYRIQ EV. (Fig. 16) Fig. 16 TAC Action Centers are […]
July Service Newsletter from the Experts at GM TAC
The latest diagnostic assistance from the professionals at the GM Technical Assistance Center is now available in the July GM Technical Assistance Center (TAC) Newsletter. It covers a number of […]
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 […]
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Previous Articles
Reducing Wi-Fi Interference in the Service Department
Front Brake Squeal Sound During Light Brake Application
Common Customer Trailer-Side Faults When Using the Trailering App
Component Names for the Air Leveling and Electronic Suspension Control Systems
Intermittent Click Sound at the Front of the Vehicle
Achieving Maximum Results in the Technician Excellence Program
Hood Ajar Message from Coolant Contamination
Rearview Camera Display Affected by Coaxial Cable Conditions
DPF Regeneration Odors
GM Service Know-How Emerging Issues
Installing HUMMER EV Accessories
MDI Manager Software Update Splits MDI 1 and MDI 2 into Separate Applications
DEF Tank Heater and Wiring Harness Updates
Using R-99 or R-95 Diesel Fuel
TCM DTCs Set on Vehicle Start Up
June Service Newsletter from the Experts at GM TAC
Service Programming Direct Launch Handling
GM Dealer Equipment (GMDE)
GM EV Safety Gloves
TAC Newsletter July 2022
Techline Connect Setup
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