The ECM detects a circuit fault on the turbocharger interstage pressure sensor a circuit. Reading cannot be used reliably for control.
Medium severity. Can I keep driving?Drive without demanding power and go to a repair shop soon. If you see a lot of blue smoke or hear a metallic noise, shut off the engine.
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Most likely causes
- Sensor failed
- Wiring or connector fault
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
- It affects emissions.
What each character of P2D21 means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- D: Subsystem depends on the code range
- 21: Specific fault in that system
Frequently asked questions
Can I keep driving with code P2D21?
Drive without demanding power and go to a repair shop soon. If you see a lot of blue smoke or hear a metallic noise, shut off the engine.
What causes code P2D21?
The most common causes are: sensor failed; wiring or connector fault.
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.