MG ZS (Gen2) P0340 Camshaft Position Sensor Circuit Fault

When the vehicle’s electronic control architecture logs a P0340 Camshaft Position Sensor Circuit Fault, the engine control module detects an invalid, missing, or inconsistent signal from the camshaft position sensor circuit. On the MG ZS, this fault can affect ignition timing, fuel injection control, engine synchronization, starting performance, and overall drivability while illuminating the Check Engine Light.

Symptoms

  • Check Engine Light illuminated
  • P0340 fault code stored in engine control module memory
  • Extended cranking before engine startup
  • Engine fails to start despite normal starter motor operation
  • Rough idle and unstable engine speed
  • Reduced engine power and hesitation during acceleration
  • Intermittent engine stalling or limp-home mode activation

Possible Causes

  • Faulty camshaft position sensor
  • Damaged camshaft position sensor wiring harness
  • Poor electrical connections or connector corrosion
  • Open circuit or short circuit in the camshaft sensor circuit
  • Damaged camshaft reluctor wheel or trigger wheel
  • Timing chain stretch affecting camshaft synchronization
  • Incorrect valve timing following previous engine repairs
  • Low voltage or grounding issues affecting sensor operation
  • Engine control module software or calibration faults

Diagnosis

Diagnosis typically begins by confirming the P0340 fault and checking for related crankshaft position, synchronization, VVT, and engine timing codes. Basic inspections should focus on the camshaft position sensor, wiring integrity, connector condition, power supply circuits, ground circuits, and sensor mounting before progressing to more advanced signal testing.

If no obvious electrical fault is found, the root cause may be linked to intermittent signal loss, wiring harness damage, timing chain wear, reluctor wheel issues, or synchronization faults that cannot be confirmed with a basic scan tool alone. Accurate fault isolation usually requires factory wiring diagrams, connector pinouts, circuit specifications, live-data values, and manufacturer diagnostic workflows that are not available through most free repair resources. Access to the OEM Service and Repair Manual can help avoid unnecessary parts replacement and significantly reduce diagnostic time.

Applicable Vehicles

This guide currently applies to the following vehicle years:

  • 2024
  • 2025
  • 2026
  • Onwards

To order the correct OEM Service and Repair Manual for your MG ZS, submit your request using the form below and our team will provide the ordering details.