P2D25 Turbocharger Interstage Pressure Sensor A Circuit Intermittent/Erratic

P2D25 is set when the interstage pressure signal jumps or drops out faster than any real pressure between two turbo stages could change, typically through brief interruptions in the circuit. No manufacturer documents the code or its rate limit publicly. The sensor matters because GM's two-stage control patent feeds the measured mid-stage pressure back to the low-pressure wastegate loop, so spikes can make that loop hunt. California requires input sensors to be monitored for faults, and the boost system for slow response. Vibration and heat near the turbochargers make loose terminals and cracked insulation the leading suspects; a wiggle test while watching live data usually finds them.

Likely causes

Symptoms

• Check engine light that comes and goes
• Surging or hunting boost
• Brief power loss over bumps

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: patents.google.com, law.cornell.edu.