MG ZS (Gen2) P0335 Crankshaft Position Sensor Circuit Fault

When the vehicle’s electronic control architecture logs a P0335 Crankshaft Position Sensor Circuit Fault, the engine control module detects an invalid, missing, or inconsistent signal from the crankshaft position sensor circuit. On the MG ZS, this fault can trigger hard starting, engine stalling, reduced engine performance, and illumination of the Check Engine Light.

Symptoms

  • Check Engine Light illuminated
  • P0335 fault code stored in engine control module memory
  • Extended cranking before engine startup
  • Engine fails to start despite normal starter motor operation
  • Intermittent engine stalling while driving
  • Reduced engine performance and poor acceleration
  • Tachometer may behave erratically or stop functioning during cranking

Possible Causes

  • Faulty crankshaft position sensor
  • Damaged crankshaft position sensor wiring harness
  • Poor electrical connections or connector corrosion
  • Open circuit or short circuit in the crankshaft sensor circuit
  • Damaged reluctor wheel or trigger wheel
  • Excessive air gap between sensor and reluctor wheel
  • Engine timing component wear affecting signal accuracy
  • Low voltage or grounding issues affecting sensor operation
  • Engine control module software or calibration faults

Diagnosis

Diagnosis typically begins by confirming the P0335 fault and checking for related engine speed, camshaft position, synchronization, and communication codes. Basic inspections should focus on the crankshaft 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, reluctor wheel issues, grounding faults, or engine timing-related problems that cannot be confirmed with a basic scan tool alone. Accurate fault isolation usually requires factory wiring diagrams, connector pinouts, circuit specifications, waveform analysis procedures, 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.