P2D21
Turbocharger Interstage Pressure Sensor A Circuit
The ECM detects a circuit fault on the turbocharger interstage pressure sensor a circuit. Reading cannot be used reliably for control.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Common causes
Ordered by how often each turns out to be the cause.
- Sensor failedCommon
- Wiring or connector faultPossible
Parts involved
- Turbo Interstage Pressure Sensor A
- Wiring Harness
- ECM
P2D21 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.