2023-2024 Colorado, Canyon, 2024 Silverado 1500, and Sierra 1500 models equipped with the 2.7L turbo (L3B) TurboMax 4-cylinder engine are experiencing a range of powertrain Diagnostic Trouble Codes (DTCs) accompanied by an illuminated Check Engine light. This issue may be attributed to a loose terminal in the transmission wiring connector​​

Vehicles Affected

Engine Affected

  • 2.7L Turbocharged 4-Cylinder (RPO L3B)
An engine diagram showing the location of the electrical connector that needs checked for loose terminal pins
An engine diagram showing the location of the electrical connector that needs to be checked for loose terminal pins (Image Courtesy GM-Techlink)

Potential Trouble Codes & Symptoms

A Check Engine Light may be set and one or more of the following DTC’S may be present P0700, P0703, P0707, P0708, P0711, P0712, P0713, P0716, P0717, P0721, P0722, P0723, P0746, P0747, P0776, P0777, P077C, P077D, P0796, P0797, P07BF, P07C0, P0815, P0816, P0826, P0841, P0842, P0843, P0960, P0962, P0963, P0964, P0966, P0967, P0968, P0970, P0971, P0960, P0962, P0963, P0964, P0966, P0967, P0968, P0970, P0971, P0960, P0962, P0963, P0964, P0966, P0967, P0968, P0970, P0971, P0960, P172A, P172B, P175E, P175F, P1761, P176B, P176C, P176D, P1775, P1783, P178F, P17CE, P17D3, P2670, P2671, P2714, P2715, P2718, P2720, P2721, P2723, P2724, P2727, P2729, P2730, P2736, P2738, P2739, P2796, P2797, P2798, P2799, P27A7, P27A8, P27A9, P27AA, P27AB, P27AC, P27AD, P27A7, P27A8, P27A9, P27AA, P27AB, P27AC, P27AD, P30BD

The electrical plug and associated terminal pins of the transmission electrical connector for the L3B Engine causing Check Engine Lights (Image Courtesy GM Techlink)
The electrical plug and associated terminal pins of the transmission electrical connector for the L3B Engine (Image Courtesy GM-Techlink)

Diagnostic and Repair Steps

Inspection: Before any engine or transmission repairs, the X175 transmission connector located under the vehicle at the rear of the automatic transmission must be inspected.
Connector Check: It’s essential to remove the connector and ensure that all terminals are correctly seated.
Terminal Tension Verification: Using the correct terminal tension tool, verify the proper terminal tension as per the Service Information.
Repair or Replacement: If poor terminal tension is identified, repair or replace the terminal as needed and verify the proper operation of the transmission system​​.

Warranty Information

If your truck has any of the symptoms of described in this article- take your vehicle to a dealership to confirm. Reference PIP5946 to your service advisor and/or technician. Any repair while the vehicle is under warranty will be covered.

Thanks to GM-Techlink for the diagrams and images included in this article