Lunch with Your FSEs June Meeting
The monthly Lunch with Your Field Service Engineers meeting will take place June 17. The one-hour meeting will be held online via Microsoft Teams and offers GM dealership technicians, shop […]
TCSC Top Issues This Week
The Techline Customer Support Center (TCSC) is available to help dealerships with diagnostic and programming issues related to Techline Connect (TLC) and the Service Programming System (SPS). TCSC has now […]
Update – Midtronics DCA-8000 Diagnostic Charger is the Only Accepted Battery Tester for Warranty Battery Replacement (U.S.)
The Midtronics DCA-8000 Diagnostic Charger (Fig. 1) is the latest generation battery charger and tester from Midtronics. It provides fast, accurate testing results and is the GM-required tool for charging […]
Rear Leaf Spring Noise and Possible Fuel Contamination
Some 2020-2026 Silverado 1500 and Sierra 1500 trucks equipped with the 3.0L diesel engine (RPO LM2, LZ0) may have a squeak or clunk sound coming from the rear of the […]
2027 Bolt State of Charge and NACS Charging Tips
The new 2027 Bolt features a 65-kWh lithium iron phosphate (LFP) high-voltage battery pack, enabling faster charging. It uses a native North American Charging Standard (NACS) charging port that provides […]
Fuse F17UA and Possible No Start Condition
A no start condition on some 2025-2026 Acadia, Traverse and Enclave models may be caused by a rear wiper motor binding or a bent wiper arm. (Fig. 16) Fuse F17UA […]
Inoperative PTO on Silverado Medium-Duty Trucks
Some 2019-2023 Silverado 4500HD/5500HD/6500HD trucks may have an intermittent condition where the available Power Take-Off (PTO) is inoperative along with DTC P251A (PTO Enable Switch Circuit) set in the PTO […]
Create Custom Data Lists in GDS 2
The latest update to GDS 2 in Techline Connect provides technicians with the ability to build personalized data parameter lists tailored for specific diagnostic sessions — identifying only the data […]
Updated Transfer Case Input Shaft Seal Installation
Seal installation depth is critical when replacing the transfer case front input shaft seal between the transmission and transfer case on 2020-2026 Silverado 2500HD/3500HD and Sierra 2500HD/3500HD trucks equipped with […]
A/C Leak Detection Dye for EVs
GM has recently established a new air conditioning refrigerant leak diagnostic procedure for GM EVs and PHEVs — including the Silverado EV, Blazer EV, Equinox EV, Bolt EV/EUV, Corvette E-Ray, […]
When and Why to Use Fuel Additives
Fuel additives are not routine maintenance items. The latest GM guidelines recommend using approved products only to address a verified vehicle condition or fuel-quality concern on GM passenger cars and […]
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 (10226.05V – U.S.) offers tips on completing the Multi-Point […]
Check 55-Way Connector if Glow Plug DTCs are Set
There may be several glow plug DTCs set on some 2024-2026 Silverado 2500HD/3500HD and Sierra 2500HD/3500HD trucks equipped with the 6.6L Duramax diesel engine (RPO L5P). DTCs may include: P066A […]
Setting Up Wired and Wireless MDI 2 Connections
There are several possible methods – both wired and wireless – to connect with the MDI 2 (EL-52100). (Fig. 4) Which is best for you depends on typical use of […]
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Previous Articles
Check 55-Way Connector if Glow Plug DTCs are Set
Setting Up Wired and Wireless MDI 2 Connections
MDI 2 Advanced Setup Technical Tips Update
April Service Newsletter from the Experts at GM TAC
Latest Techline Connect Update and DISG Release Include New Firewall Exclusions
Engine Oil Consumption Guidelines
2nd-Row Rear Seat Operation and Diagnostic Tips for Full-Size SUVs
1.2L Engine EVAP System Diagnosis — Disconnect EVAP Leak Check Pump Before Smoke Test
Front View Camera Diagnosis and Part Restriction
Midtronics DCA-8000 Diagnostic Charger is the Only Accepted Battery Tester for Warranty Battery Replacement
High Resistance in Glass Breakage Loop May Lead to Dead Battery
Power Steering Leak Diagnosis Using Fluorescent Dye
GM Service Know-How Emerging Issues
DCA-8000
Troubleshooting
Guide
TAC Newsletter April 2026
TAC Newsletter March 2026
MDI-2 Connections and Advanced Setup 2026
CX Connect Case Creation Help + Tips and Tricks
