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 […]
Vehicle-Wide Programming Status Summary Now Includes All Control Modules
The Vehicle-Wide Programming (VWP) feature in Techline Connect (TLC) has been updated with several enhancements in the latest software release. VWP, which allows multiple control modules to be programmed during […]
2025 Model Year Transmission Fluid Capacities Chart
A new TechLink reference chart is now available covering transmission fluid capacities. The 2025 Transmission Fluid Capacities chart can be viewed under the Reference Charts menu or by selecting the […]
Key Fob Learning on 2025 Police and Special Service Vehicles
The 2025 Tahoe can be equipped with special service vehicle packages for police use (RPO 9C1) (Fig. 7; shown with aftermarket equipment) and special service use (RPO 5W4). Fig. […]
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 […]
First-Ever 2026 Cadillac VISTIQ Debuts
The first-ever all-electric 2026 Cadillac VISTIQ (Fig. 1) is now in production and hitting dealerships. Slotting between the LYRIQ and new ESCALADE IQ in Cadillac’s EV lineup, the VISTIQ delivers […]
New Rear Heating/Cooling System Provides 3rd-Row Comfort
The 2025-2026 ESCALADE IQ/IQL and VISTIQ feature a first-of-its-kind rear cabin heating/cooling system (RPO C69) for 3rd-row passengers. The separate HVAC system, controlled by using the Front Command Center touchscreen […]
Troubleshooting Tips for the DCA-8000P Diagnostic Charger
The GM DCA-8000P Diagnostic Charger – an Essential Tool for all U.S. dealerships – is the latest generation battery charger and tester from Midtronics that provides fast, accurate testing results. […]
New Part Number Released for Silverado and Sierra Half Shafts
A new half shaft part number has been released for 2019-2025 Silverado 1500 and Sierra 1500 trucks equipped with the Z71 Off-Road Suspension Package (RPO Z7X). (Fig. 20) The new […]
Remove Protective Films on Overhead Console During PDI on the ESCALADE IQ/IQL
During the Pre-Delivery Inspection (PDI) of the 2025-2026 ESCALADE IQ/IQL, all interior protective coverings should be removed as covered on the PDI form, including on the front overhead console. (Fig. […]
Diagnostic Tips for Audio and Display Screen Concerns on IOK Radios
There may be several display screen concerns and other conditions on the infotainment system (RPO IOK) of some 2022-2025 Silverado, Tahoe, Suburban, Sierra, Yukon, HUMMER EV; 2024-2025 Corvette, Silverado HD […]
Required Information for Restricted IOK Radios
The infotainment system (RPO IOK) on 2022-2025 Silverado, Tahoe, Suburban, Sierra, Yukon, HUMMER EV; 2024-2025 Corvette, Silverado HD and Sierra HD models is on restriction. (Fig. 3) If the radio […]
Power Doors OTA Update Released for 2025 Escalade
2025 Escalade, Escalade ESV and Escalade V-Series models built early in the model year offered a power-assist exterior door system (RPO APD with R6W) that has power-assisted door opening and […]
QR Code Scanning Helps Avoid Input Mistakes When Programming Modules
When replacing a valve body or transmission on a GM vehicle, it is essential to gather Mechanical Characterization & Virtual Matching (MCVM) data from the cloud. Due to manufacturing variations, […]
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 previews the 2025 Corvette ZR1. (Fig. 12) Fig. […]
New TAC Response Requested Process
A new GM Technical Assistance Center (TAC) process has been implemented to ensure the customer is being considered when TAC is working in partnership with dealership technicians to repair customers’ […]
Keep Your Cool — Air Conditioning Refrigerant Leak Diagnostic Tips
All current GM vehicles are manufactured with fluorescent dye installed in the air conditioning refrigerant system. The dye mixes and flows with the A/C compressor oil to help in locating […]
Water Leak at the A-Pillar Body Plug
There may be several inoperative electrical features on some 2019-2025 Blazers. (Fig. 4) These conditions may include inoperative door chimes and door lamps, inoperative power mirrors or a distorted driver-side […]
Unlatching the Front Compartment Hood with a Weak 12V Battery
The front compartment hood on some 2024-2025 Corvette models may not fully unlatch when one of the hood release buttons is pressed if the 12V battery is weak, resulting in […]
Differences in Approach Lighting on Mid-Size SUVs
The approach lighting on the 2024-2025 Traverse and Acadia has several differences compared to the lighting elements on the 2025 Enclave. It’s important to understand these differences when diagnosing any […]
April 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 April GM Technical Assistance Center (TAC) Newsletter. It covers a number of […]
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Previous Articles
Outside Rearview Mirror Glass Removal
Executive Second-Row Seat Operation
Super Cruise Disengages or is Unavailable
2025 Cadillac VISTIQ TAC Action Center
GM Service Know-How Emerging Issues
Dealer Case Management Tips for TCSC Submissions
EVAP System on the New 1.2L Engine Requires Updated Leak Test Diagnostics
NACS Charging Adapters Designed for Public DC Chargers Only
New Feedback Process on Shipping Parts to the Warranty Parts Center
FSE Technician Recognition Awards – 1st Quarter 2025
March Service Newsletter from the Experts at GM TAC
DCA-8000
Troubleshooting
Guide
TAC Newsletter May 2025
TAC Newsletter April 2025
Techline Connect Tips November 2024
DCM Case Submission & Best Practices Guide
