Testing for Diesel Fuel System Contamination
One of the most common sources of diesel fuel system contamination is automotive fluids, which often include gasoline and Diesel Exhaust Fluid (DEF) that may have been mistakenly added to […]
Archive for May, 2023
Engine Performance in Extremely Cold Weather Conditions
While driving in extremely cold weather conditions, poor engine performance may be noticed on some 2013-2021 Encore and Trax models equipped with the 1.4L engine (RPO LUV). (Fig. 10) The […]
Fluid Leak Between the Transmission and Transfer Case
Some 2020-2024 Silverado 2500/3500 and Sierra 2500/3500 models equipped with the 10L1000 10-speed automatic transmission (RPO MGM, MGU) and four-wheel drive transfer case (RPO NQF, NQH) may have a fluid […]
Neutral Idle Control Feature on 6-Speed Automatic Transmission
A single bump feeling may be felt when coming to a stop on some 2017-2022 Encore and Trax models equipped with the 6T40 6-speed automatic transmission (RPO MNH, MNK) and […]
New Design Intake Manifold Addresses Poor Engine Performance
Some 2011-2016 Cruze; 2012-2020 Sonic; and 2013-2020 Encore and Trax models equipped with the 1.4L engine (RPO LUV) may experience a loss of power or several other engine performance conditions […]
Free Spinning or Grinding Starter Sounds
A starter grinding sound or free spinning sound under the hood may be heard on some 2019-2020 Enclave and Traverse models equipped with the 3.6L V6 engine (RPO LFY). In […]
May 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 May GM Technical Assistance Center (TAC) Newsletter. It covers a number of […]
New Battery Cell Chemistry Identification
Before replacing a high voltage battery pack or battery section on 2017-2023 Bolt EV and 2022-2023 Bolt EUV models (Fig. 10), the battery pack must be correctly identified. Fig. […]
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. This month the seminar covers electric vehicle battery pack uncrating and crating with […]
New Trailer Tire Pressure Sensors Offer Increased Capability
The trailering app (RPO ZL6) available on 2020-2022 Silverado 1500, Silverado 2500HD/3500HD, Sierra 1500 and Sierra 2500HD/3500HD trucks includes Trailer Tire Pressure and Temperature Monitoring. (Fig. 1) As part of […]
Inoperative USB Port Diagnosis
Many 2020-2023 GM models feature USB ports for mobile device charging and data connection. If a smartphone or other device does not charge or transfer data properly when connected to […]
Avoid the TUN# Label When Cleaning Transmission Cases
Recently, a number of 8-speed and 10-speed transmissions have been returned to the Warranty Parts Center with missing or unreadable Transmission Unique Label (TUN) labels. In some cases, the label […]
High-Pitched Whistling Sound at Idle
A high-pitched whistling or squeal sound may be heard at idle on some 2022-2023 Silverado 2500HD/3500HD and Sierra 2500HD/3500HD models equipped with the 6.6L V8 gasoline engine (RPO L8T). The […]
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Previous Articles
Transmission Whine Sound
March Service Newsletter from the Experts at GM TAC
Vehicle Alignment and Super Cruise
Rear Axle Differential Lock Control Actuator Condition
Diesel Exhaust Fluid Supply Pipe Contamination
FSE Technician Recognition Awards – 1st Quarter 2024
Crankshaft Bearing Diagnosis
Convertible Top Water Leak
Power Tonneau Cover Tips
GM Service Know-How Emerging Issues
MDI 2 Advanced Setup Technical Tips Update
Fuel Feed Pipe Buzzing Sound
February Service Newsletter from the Experts at GM TAC
Exhaust Resonator Rattle
Heated Steering Wheel Operation During a Remote Start
GM Dealer Equipment (GMDE)
TAC Newsletter March 2024
TAC Newsletter February 2024
Techline Connect Tips March 2023
