General Motors has released a new service update for the GMC Terrain crossover. According to the bulletin, owners might see the Malfunction Indicator Light illuminated, with the diagnostic system logging error codes P228C, P0089, and/or P00C6. This issue stems from the Engine Control Module and fuel pump operation, but it can be resolved with a software update.

The service update was published on January 27, 2026, under number N252524761. GM specifies that it applies only to the 2023 model year GMC Terrain. The bulletin is valid until February 28, 2029.

The fix is performed by an authorized GM dealer at no cost to the customer. No parts replacement is needed; dealers are instructed to reprogram the Engine Control Module without any hardware changes.

Before the repair, the dealer must verify that the specific vehicle is included in the program using the Investigate Vehicle History system in Global Warranty Management. The update covers both vehicles in dealer inventory and customer cars returning to service for any reason. GM notes that the firmware can be installed during routine maintenance, so a separate visit solely for this procedure is not necessary.

Customers who previously paid for repairs related to this issue can request reimbursement. Claims must be submitted by February 28, 2027, following GM's guidelines.