P0389
Fix within a few daysCrankshaft Position Sensor 'B' Circuit Intermittent
Code P0389 means your crankshaft position sensor "B" circuit has an intermittent signal. Common causes: Faulty sensor (70%), wiring issues (25%). Drivability: Limit driving, fix within a few days. Repair cost: $50-$200 DIY, $150-$500 professional.
Can I Drive With P0389?
Limit driving, fix within a few days
Essential trips under 10 miles, avoid highways and heavy traffic where stalling would be dangerous.
Stop driving immediately if: Flashing CEL, engine stalls repeatedly, vehicle won't start at all, significant power loss
Symptoms of P0389
- 1Engine cranks but won't start
- 2Engine stalls unexpectedly
- 3Engine runs rough or misfires
- 4Reduced engine power
- 5Intermittent check engine light
Common Causes of P0389
Parts most likely causing this code, ranked by probability
The sensor's internal components fail, causing it to intermittently lose signal or send incorrect data to the engine computer.
70% of P0389 cases are fixed by replacing the crankshaft position sensor
Frayed wires, loose pins, or corrosion disrupt the electrical signal path between the sensor and the engine computer.
25% of P0389 cases are fixed by repairing or replacing the sensor wiring/connector
The engine computer fails to correctly interpret or process the crankshaft position sensor signal.
5% of P0389 cases are fixed by replacing the engine control module
Check These First (Before Buying Parts)
- Visually inspect the crankshaft position sensor's wiring and electrical connector for any signs of damage, fraying, corrosion, or looseness.
- Ensure the battery terminals are clean and tight, as low voltage can sometimes cause intermittent sensor issues.
How to Diagnose P0389
- 1Visually inspect the crankshaft position sensor wiring and connector for damage, corrosion, or looseness.
- 2Check for proper voltage and ground at the crankshaft position sensor connector using a multimeter.
- 3Test the crankshaft position sensor's resistance and signal output according to service manual specifications.
- 4Use a scan tool to monitor live data for the crankshaft position sensor signal while wiggling the wiring.
- 5If all sensor and wiring checks pass, consider testing the engine control module (PCM/ECM) as a last resort.
P0389 on Popular Vehicles
Ford F-150
2004-2024P0389 on F-150s is frequently traced to a failing crankshaft position sensor. Access can be challenging depending on the engine (e.g., 5.4L vs. 3.5L EcoBoost).
75% fixed by replacing the crankshaft position sensor
Honda Accord
2003-2024Honda Accords with P0389 often have issues with the crankshaft position sensor itself or its wiring harness, especially where it routes near hot engine components or moving parts.
70% fixed by replacing the crankshaft position sensor
Chevrolet Silverado
2007-2024For Chevrolet Silverados, P0389 can be due to a faulty sensor or corrosion in the connector, particularly in areas exposed to road salt or moisture.
70% fixed by replacing the crankshaft position sensor
Frequently Asked Questions
What does P0389 mean?
P0389 indicates that the engine computer has detected an intermittent electrical signal from the crankshaft position sensor "B" circuit. This sensor tells the computer the exact position and rotational speed of the crankshaft.
Can I drive with P0389?
Limit driving, fix within a few days. An intermittent crankshaft position sensor can cause unexpected engine stalling, hard starting, or a no-start condition, which is a safety hazard.
Will P0389 clear itself?
No, P0389 will not clear itself. The intermittent fault will persist until the underlying issue with the sensor, wiring, or engine computer is diagnosed and repaired.
How do I fix P0389 myself?
Start by visually inspecting the sensor's wiring and connector. If no obvious damage is found, test the sensor's output with a multimeter. If the sensor is faulty, replace the crankshaft position sensor.
How much does it cost to fix P0389?
A DIY repair for P0389 typically costs $50-$200 for a new crankshaft position sensor. Professional repair at a shop costs $150-$500, including diagnosis and labor.
P0389 keeps coming back - why?
P0389 keeps coming back if the initial repair didn't address the root cause. This often means the wiring or connector was overlooked, or a rare PCM fault is present. Ensure thorough inspection of the entire circuit.
Will P0389 fail emissions/smog test?
Yes, P0389 will cause your vehicle to fail an emissions or smog test. The check engine light being on indicates a fault in a system monitored by the emissions control system.
What's the difference between P0389 and P0335?
P0335 indicates a general circuit malfunction for the primary crankshaft position sensor (often "A"), meaning a continuous fault. P0389 specifically points to an intermittent circuit malfunction for a secondary crankshaft position sensor (often "B"), implying the signal comes and goes.
P0389 on Ford F-150?
On Ford F-150s, P0389 is often caused by a failing crankshaft position sensor, especially on higher mileage vehicles. The sensor's location can vary by engine, sometimes requiring removal of other components for access.
Questions to Ask Your Mechanic
Did you check the wiring harness and connector for the crankshaft position sensor for any damage or corrosion before condemning the sensor?
Good answer: Yes, I thoroughly inspected the wiring from the sensor back to the PCM, checked for continuity, and tested the connector for proper pin tension and corrosion. Everything looked good, so the sensor itself is the most likely culprit.
Repair Cost Estimate
DIY Repair
Parts only
$50-$200
Shop Repair
Parts + labor
$150-$500
Save $100-$300 by doing it yourself
Difficulty
intermediate
Time
1-3 hours
Intermediate. Accessing the crankshaft position sensor can be challenging on some vehicles, requiring specific tools or removal of other components. Testing with a multimeter also requires some basic electrical diagnostic knowledge.
Cost of Waiting
Ignoring P0389 can lead to your engine stalling unexpectedly while driving, creating a dangerous situation. It can also prevent your vehicle from starting, leaving you stranded. Continued intermittent misfires, if present, send unburned fuel to your catalytic converter, potentially causing a $800-$2,500 converter replacement.
While You're In There...
The crankshaft position sensor wiring is often routed in areas prone to heat or vibration. Inspecting the entire harness for chafing or damage can prevent future electrical issues.
Tools You'll Need
- Basic hand tools (sockets, wrenches)
- Multimeter
- Possibly a scan tool for live data
- Jack and jack stands (for access)
P0389 is a common sensor code. While it can cause frustrating starting or stalling issues, it's usually a straightforward fix by replacing the crankshaft position sensor, and your engine will run reliably afterward.
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Your Next Steps
Step 1: Check the crankshaft position sensor's wiring and connector. Look for any cuts, abrasions, corrosion, or loose connections. Make sure the connector is fully seated.
Step 2: If the wiring looks good, use a multimeter to test the sensor's resistance and signal output according to your vehicle's service manual. Compare readings to specifications.
Step 3: If the sensor tests faulty or the wiring is damaged, you'll likely need a new crankshaft position sensor and potentially a pigtail connector repair kit.