P25D6
- Powertrain
- Manufacturer-specific
- Emissions
Diagnose soon
Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
Exhaust Heat Exchanger Exhaust Bypass Valve A Position Sensor Stop Performance
This code is in our catalogue but has not yet been through editorial review, so the guidance below is limited to what our structured data supports. We publish deeper diagnostic content only after a code has been reviewed — here is why.
During self-calibration of the exhaust heat exchanger bypass valve A, the position sensor never reached the expected mechanical stop. The controller cannot zero the position reference, so commanded openings will be inaccurate.
A trouble code records what a control module measured. It does not identify which part failed. Test before replacing anything.
- Safe to drive
- Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
- Urgency
- Diagnose soon
- Will it pass emissions
- No
- Check engine light
- Solid
| # | Cause | How often | Component |
|---|---|---|---|
| 1 | Soot or carbon deposits prevent valve from reaching the stop | Very common | — |
| 2 | Worn linkage between actuator and valve flap | Common | — |
| 3 | Position sensor not aligned with valve shaft | Common | — |
Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.
- Exhaust Heat Exchanger
- Bypass Valve Actuator
- Position Sensor
- Definition
- Generic code set (SAE J2012 / ISO 15031-6) via the OBDexopen database, dedicated to the public domain under CC0-1.0.
- Diagnostic guidance
- Written and reviewed in-house. See our editorial policy.
- Review status
- Awaiting review
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