Crankshaft Position Sensor B Circuit High
The P0388 code means the vehicle's onboard diagnostic system has detected: Crankshaft Position Sensor B Circuit High. This is a critical severity code.
- Keep driving?
- No -- stop driving
- DIY difficulty
- moderate
- Estimated cost
- $80 - $400 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Engine may not start
- Stalling
- No signal from sensor B
Probable Causes (Ranked by Likelihood)
- Open circuit in crank sensor B wiring Very High
- Failed sensor (open) High
- Disconnected connector Moderate
- PCM input open Low
Step-by-Step Diagnostic Procedure
-
Check connector is seated.
-
Measure sensor resistance.
-
Test wiring continuity.
-
Replace sensor if wiring is intact.
Frequently Asked Questions
What does circuit high mean on crank sensor B?
An open circuit or disconnected sensor causes the signal voltage to float high.
Can I just use sensor A?
Some engines can run on one crank sensor in degraded mode, but it is not reliable for long-term operation.
How long does crank sensor replacement take?
Typically 30-60 minutes for sensor replacement, depending on accessibility.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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