Check 55-Way Connector if Glow Plug DTCs are Set

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 […]

April 27, 2026
Setting Up Wired and Wireless MDI 2 Connections

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 […]

April 27, 2026
MDI 2 Advanced Setup Technical Tips Update

MDI 2 Advanced Setup Technical Tips Update

With the MDI Manager application software, the MDI 2 can be configured to communicate with a PC using several possible networks, such as a USB cable, ethernet cable, Wireless Local […]

April 27, 2026
April Service Newsletter from the Experts at GM TAC

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 […]

April 27, 2026
Latest Techline Connect Update and DISG Release Include New Firewall Exclusions

Latest Techline Connect Update and DISG Release Include New Firewall Exclusions

The latest Techline Connect update and GM Dealer Infrastructure & Security Guidelines (DISG) release include new firewall exceptions for Techline Connect applications. For the recent Techline Connect application update, your […]

April 24, 2026
Engine Oil Consumption Guidelines

Engine Oil Consumption Guidelines

All engines require oil to lubricate and protect internal moving components from wear. When a piston moves down its cylinder, a thin film of oil is left on the cylinder […]

April 24, 2026
2nd-Row Rear Seat Operation and Diagnostic Tips for Full-Size SUVs

2nd-Row Rear Seat Operation and Diagnostic Tips for Full-Size SUVs

The 2nd-row seats (RPO AT6, ATV) available on 2021-2026 Tahoe, Suburban, Yukon, Escalade and 2025-2026 ESCALADE IQ models include a number of adjustment features, such as fore/aft, recline, folding and […]

April 24, 2026
1.2L Engine EVAP System Diagnosis -- Disconnect EVAP Leak Check Pump Before Smoke Test

1.2L Engine EVAP System Diagnosis — Disconnect EVAP Leak Check Pump Before Smoke Test

The new 1.2L engine (RPO LBP), introduced in the 2025 Envista, Encore GX, Trax and Trailblazer, features E85 compatibility. As part of the updates to the Evaporative Emission (EVAP) system, […]

April 24, 2026
Front View Camera Diagnosis and Part Restriction

Front View Camera Diagnosis and Part Restriction

There may be several DTCs set and ADAS-related messages displayed on the Driver Information Center related to the B174W Front View Camera Module (ACP2) (Fig. 14) on some 2024-2026 Chevrolet, […]

April 24, 2026
TCSC Top Issues This Week

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 […]

April 22, 2026
Midtronics DCA-8000 Diagnostic Charger is the Only Accepted Battery Tester for Warranty Battery Replacement

Midtronics DCA-8000 Diagnostic Charger is the Only Accepted Battery Tester for Warranty Battery Replacement

The Midtronics DCA-8000 Diagnostic Charger is the latest generation battery charger and tester from Midtronics. It provides fast, accurate testing results and is the GM-required tool for charging and testing […]

April 13, 2026
High Resistance in Glass Breakage Loop May Lead to Dead Battery

High Resistance in Glass Breakage Loop May Lead to Dead Battery

There may be a low or dead battery, no crank due to a dead battery, or an unwanted theft-deterrent alarm on some 2021-2026 Tahoe, Suburban, Yukon and Escalade models. (Fig. […]

April 13, 2026
Power Steering Leak Diagnosis Using Fluorescent Dye

Power Steering Leak Diagnosis Using Fluorescent Dye

A fluid leak may be visible on the steering gear (Fig. 6) or power steering fluid lines on some 2015-2026 Silverado 2500HD/3500HD and Sierra 2500HD/3500HD trucks. The leak may be […]

April 13, 2026
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. This month the seminar talks about high viscosity POE oil and fluorescent leak […]

April 13, 2026