Crankshaft Position Sensor B Circuit High Input
The crankshaft position sensor B circuit is detecting an abnormally high voltage input, preventing the engine computer from accurately reading crankshaft position. This code typically causes immediate no-start conditions or severe running issues because the PCM cannot properly time fuel injection and ignition without valid CKP sensor data.
What You Might Notice
- Engine will not start or fails to crank
- Tachometer reading zero or fluctuating erratically
- Severe hesitation and loss of power during acceleration
- Repeated stalling immediately after starting
- Check engine light illuminated with stored fault code
Most Common Causes
- 1
Defective crankshaft position sensor
The CKP sensor B has failed internally or is producing an out-of-range signal voltage. This is the most common cause of this code.
- 2
Open or shorted wiring to CKP sensor
Damaged, broken, or corroded wiring harness between the sensor and PCM creates improper signal transmission, causing high voltage readings.
- 3
Corroded or contaminated sensor connector
Moisture, salt, or corrosion at the CKP sensor connector increases resistance and disrupts the electrical signal circuit.
- 4
Alternator overcharging or PCM malfunction
Excessive charging voltage or faulty PCM electronics can cause abnormal sensor signal interpretation or module failure.
How to Diagnose It
- 1
Check Defective crankshaft position sensor — The CKP sensor B has failed internally or is producing an out-of-range signal voltage. This is the most common cause of this code.
- 2
Check Open or shorted wiring to CKP sensor — Damaged, broken, or corroded wiring harness between the sensor and PCM creates improper signal transmission, causing high voltage readings.
- 3
Check Corroded or contaminated sensor connector — Moisture, salt, or corrosion at the CKP sensor connector increases resistance and disrupts the electrical signal circuit.
- 4
Check Alternator overcharging or PCM malfunction — Excessive charging voltage or faulty PCM electronics can cause abnormal sensor signal interpretation or module failure.
How to Fix It
- 1
Replace crankshaft position sensor B
Remove the faulty CKP sensor and install a new OEM or quality aftermarket replacement. Ensure proper installation depth and gap if applicable to your vehicle.
- 2
Inspect and repair sensor wiring harness
Check the entire CKP sensor B wiring circuit for breaks, corrosion, or damage. Repair or replace damaged sections and ensure all connections are secure and clean.
- 3
Clean or replace sensor connector
Disconnect the CKP sensor connector and clean both male and female terminals with electrical contact cleaner or fine sandpaper. Replace the connector if pins are damaged or corroded beyond cleaning.
- 4
Test alternator output and PCM function
Verify alternator output voltage is within specification (typically 13.5-14.5V at idle). If alternator is overcharging, have it replaced. If sensor and wiring are good, have the PCM diagnosed for internal faults.
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