Camshaft Position Sensor "B" Circuit High (Bank 1)
The camshaft position sensor "B" is detecting a voltage signal that is lower than the acceptable range, indicating a circuit problem between the sensor and engine control module. This prevents the PCM from accurately reading camshaft timing, which can cause rough running, misfires, and difficulty starting.
What You Might Notice
- Check Engine Light illuminated
- Engine bucking or surging during acceleration
- Engine dies or stalls intermittently
- Hard starting or no-start condition after restart
- Rough idle or stumbling on cold starts
Most Common Causes
- 1
Open ground circuit to sensor
A broken or disconnected ground wire between the camshaft position sensor B and the PCM causes the signal voltage to read low. This is one of the most common causes of this code.
- 2
Open signal circuit wire
A break or disconnection in the signal wire between the sensor and PCM prevents proper voltage transmission, causing the low voltage fault condition.
- 3
Camshaft Position Sensor B failure
The sensor itself can fail internally or become shorted to voltage, producing an out-of-range low signal that the PCM cannot interpret correctly.
- 4
Short to 5-volt supply in signal circuit
A wiring short or internal sensor fault may cause the signal circuit to reference voltage incorrectly, reading lower than expected by the PCM.
How to Diagnose It
- 1
Check Open ground circuit to sensor — A broken or disconnected ground wire between the camshaft position sensor B and the PCM causes the signal voltage to read low. This is one of the most common causes of this code.
- 2
Check Open signal circuit wire — A break or disconnection in the signal wire between the sensor and PCM prevents proper voltage transmission, causing the low voltage fault condition.
- 3
Check Camshaft Position Sensor B failure — The sensor itself can fail internally or become shorted to voltage, producing an out-of-range low signal that the PCM cannot interpret correctly.
- 4
Check Short to 5-volt supply in signal circuit — A wiring short or internal sensor fault may cause the signal circuit to reference voltage incorrectly, reading lower than expected by the PCM.
How to Fix It
- 1
Inspect and repair ground circuit
Check the ground wire from the camshaft position sensor B to the engine block or PCM ground. Look for corrosion, breaks, or loose connectors. Clean contacts and reconnect or repair damaged wiring.
- 2
Check and repair signal wiring
Inspect the signal wire between sensor B and the PCM for cuts, pinches, or corrosion. Use a multimeter to verify continuity. Repair or replace damaged sections of wiring harness.
- 3
Replace camshaft position sensor B
If wiring tests pass, the sensor itself is likely faulty. Locate sensor B on the camshaft or cylinder head, disconnect it, and install a new OEM or quality replacement sensor.
- 4
Verify PCM connector and grounds
Inspect the PCM electrical connectors for corrosion, bent pins, or loose connections. Ensure all engine ground straps are clean and properly attached to the block and chassis.
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