Code
P0342
GWM
P — Powertrain
- Camshaft Position Sensor Low
AI status
Completed
Completed
100%
Causes
- Damaged or shorted sensor wiring (short to ground)
- Corroded/loose connector or poor pin contact at sensor
- Faulty camshaft position sensor (Hall or magnetic type)
- Intermittent harness damage (chafing, broken conductor)
- Missing or weak reference voltage or ground at sensor
- PCM/ECM internal fault (rare)
Symptoms
- Check Engine Light (MIL) illuminated
- Hard starting or no-start condition
- Engine may run rough, misfire, or stall
- Poor idle quality and reduced drivability
- Reduced fuel economy and performance
- Possible multiple-cylinder misfire codes or crank/cam correlation faults
What to check
- Read freeze frame data and pending codes with a scan tool
- Verify exact code text (e.g., CAM A circuit low) and note bank/position
- Visually inspect sensor connector and wiring for damage, corrosion, oil, or loose pins
- Backprobe sensor connector while cranking/running and observe signal voltage with a multimeter or oscilloscope
- Check sensor supply/reference voltage (typically 5 V) and ground presence at connector
- Measure sensor resistance (if specified by service manual) and compare to spec
Signal parameters
- Typical Hall-type cam sensor: 0–5 V square wave output; switching between ~0.0–1.0 V (low) and ~4.0–5.0 V (high)
- Trigger threshold that may set P0342: signal held low (near 0 V) or below expected low threshold during cranking/running
- Reference voltage to sensor usually ~5 V from ECM; ground continuity required
- Frequency depends on engine speed and engine configuration (tens to hundreds of Hz)
- Passive (VR) sensors produce AC voltage; low AC amplitude at cranking or idle indicates weak/shorted VR circuit
Diagnostic algorithm
- Connect a scan tool and clear codes, then try to re-create P0342 and capture freeze frame values
- Visually inspect sensor and connector for corrosion, bent pins, oil intrusion, or damage
- Backprobe the sensor connector: verify reference voltage (≈5 V) and ground presence with ignition ON
- Measure sensor signal while cranking and running: for Hall sensor expect a pulsed 0–5 V square wave; for VR expect AC voltage. If signal is absent or stuck low, proceed
- Check continuity from sensor signal pin to ECM pin and inspect for shorts to ground or battery voltage (use multimeter, check resistance and for short circuits)
- Perform a wiggle test on harness and connectors while monitoring live data to detect intermittent wiring faults
- If wiring and connector are good and reference voltage/ground are present, replace the camshaft position sensor and retest
- If replacement sensor does not fix it, inspect timing components (timing chain/belt, phasers) and verify camshaft rotation relative to crankshaft
- If wiring, sensor and mechanical timing are verified, test or replace the ECM as a last resort (follow manufacturer service procedures)
Likely causes
- Corroded connector terminals at the sensor
- Broken or shorted wire between sensor and ECM (most common)
- Failed camshaft position sensor
- Loss of sensor reference voltage or ground
- Sensor damaged by oil ingress or engine debris
Fault status
Status
Camshaft position sensor circuit low — ECM detected sensor signal voltage below expected threshold. Possible wiring short to ground, bad sensor, or loss of reference/ground.
Repair difficulty: Medium
Diagnostic time: 0.5-2.5 hours
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