Crankshaft Position Sensor B Circuit Intermittent
The P0389 code means the vehicle's onboard diagnostic system has detected: Crankshaft Position Sensor B Circuit Intermittent. 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
- Intermittent stalling
- Check Engine Light on
- Random no-start
- Engine hesitation
Probable Causes (Ranked by Likelihood)
- Loose crank sensor B connector Very High
- Intermittent wire break High
- Sensor failing under heat Moderate
- Vibration-induced fault Low
Frequently Asked Questions
Why does the engine stall randomly?
An intermittent crank sensor signal causes momentary loss of engine position data, which can stall the engine.
Can heat cause P0389?
Yes, heat soak failure is common with crank sensors. The sensor may work cold and fail when hot.
How do I catch the intermittent fault?
Drive with a scan tool recording data. Look for momentary signal dropouts from sensor B.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Monitor sensor B signal while performing wiggle test.
-
Check connector pins for looseness.
-
Inspect wiring at stress points.
-
Test sensor during hot and cold conditions.
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- 2010-2020 Ford F-250 (6.7L Diesel)
- 2012-2019 Ram 2500 (6.7L Cummins)
- 2008-2018 Chevrolet Silverado 2500 (6.6L Duramax)
- 2011-2020 Toyota 4Runner (4.0L V6)
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