P034A
- Powertrain
- Generic (SAE)
- Emissions
Diagnose soon
Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
Crankshaft Position Sensor - Crankshaft Start Position Incorrect
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.
At engine start the crankshaft position reported by the sensor does not match the calibrated start window — typically a wrong tone-wheel installation, sensor air gap, or PCM not synchronised after a relearn.
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 | Tone wheel misindexed or relearn pending | Very common | — |
Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.
- Crankshaft Position Sensor
- Flywheel
- 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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