MG ZS (Gen2) P0507 Idle Speed Higher Than Expected

The P0507 Idle Speed Higher Than Expected fault indicates that the engine control module (ECM) has detected an idle engine speed that is consistently higher than the manufacturer’s specified target. The ECM continuously monitors engine RPM, throttle position, intake airflow, and engine operating conditions. If the actual idle speed remains above the commanded value for a specified period, the ECM stores DTC P0507. This fault applies to the MG ZS Gen2 (ZS11 platform), introduced from 2024 onwards.

Symptoms

  • Check Engine Light illuminated
  • High engine idle speed
  • Engine revs remain elevated after starting
  • Idle speed fluctuates
  • Harsh engagement when shifting into gear
  • Increased fuel consumption
  • Hesitation during deceleration
  • Additional throttle body or intake-related fault codes may be present

Possible Causes

  • Vacuum leak in the intake system
  • Dirty or sticking electronic throttle body
  • Faulty electronic throttle actuator
  • Air leak after the mass airflow (MAF) sensor (if equipped)
  • PCV valve stuck open
  • Intake manifold gasket leak
  • Faulty throttle position sensor
  • Faulty accelerator pedal position sensor
  • Damaged wiring or electrical connectors
  • Engine control module (ECM) software or hardware fault (rare)

Diagnosis

Diagnosis begins by confirming the stored fault code and reviewing freeze-frame and live data using a compatible diagnostic scan tool. The intake system should be inspected for vacuum leaks, while the electronic throttle body should be checked for carbon deposits, sticking, or improper operation. Live data from the throttle position sensor, accelerator pedal position sensor, manifold absolute pressure (MAP) sensor, and engine idle control parameters should be analysed to verify correct operation. Manufacturer diagnostic procedures may also include smoke testing the intake system, electronic throttle actuator testing, throttle body relearn procedures, and inspection of the PCV system.

For vehicles operating in New Zealand, following OEM diagnostic procedures helps distinguish between vacuum leaks, throttle body faults, and sensor-related issues, reducing unnecessary replacement of electronic throttle components.

Accurately diagnosing this fault often requires manufacturer testing procedures, wiring diagrams, connector pinouts, electronic throttle control specifications, intake system schematics, throttle relearn procedures, and system calibration information. Access to the factory service manual significantly reduces diagnostic time and helps prevent unnecessary parts replacement.

Applicable 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.