Reduced Power and Check Engine Light on GMC Sierra 1500

The throttle position sensor (TPS) on the GMC Sierra 1500 Hybrid is notorious for failure which causes:

• Check engine light
• Reduced Power message
• OBD trouble code P2135

This issue is related to the throttle position sensor on the gasoline engine, and can be caused by faulty wiring to the TPS, bad connection at the TPS, or a failed TPS. Note, this does not affect the hybrid drive system.

To correct this issue, the wiring harness, connector, and throttle position sensor must be inspected, tested, and/or replaced. The most common cause is a faulty TPS.