MG ZS (Gen2) Push Button Start Not Working

A Push Button Start Not Working fault indicates that the keyless starting system is unable to authorize or initiate engine starting. The system relies on the Smart Key, Body Control Module (BCM), immobilizer, Engine Control Module (ECM), brake pedal switch, start/stop button, and key detection antennas to verify driver authorization before activating the starter circuit. If a fault occurs in any of these components or their communication network, the engine may fail to crank or start, and one or more Diagnostic Trouble Codes (DTCs) may be stored. This fault applies to the MG ZS Gen2 (ZS11 platform), introduced from 2024 onwards.

Symptoms

  • Push button start does not respond
  • Engine will not crank
  • Engine will not start
  • Smart Key Not Detected message displayed
  • Keyless entry may not function
  • Immobilizer warning light illuminated
  • Start/Stop button warning message displayed
  • Multiple warning lights illuminated
  • Intermittent starting problems
  • Starting system-related Diagnostic Trouble Codes (DTCs) stored

Possible Causes

  • Flat smart key battery
  • Faulty smart key fob
  • Faulty Start/Stop button
  • Brake pedal switch fault
  • Faulty Smart Key antenna
  • Body Control Module (BCM) fault
  • Immobilizer system fault
  • Starter relay fault
  • Low vehicle battery voltage
  • Damaged wiring harness
  • Loose or corroded electrical connectors
  • CAN Bus communication fault
  • Engine Control Module (ECM) fault

Diagnosis

Diagnosis begins by retrieving all stored Diagnostic Trouble Codes (DTCs) from the BCM, ECM, immobilizer, Smart Key system, and other related control modules using a compatible diagnostic scan tool. Live data should be reviewed to verify key authentication, brake pedal switch status, start button input, and starter authorization.

The technician should inspect the smart key battery, Start/Stop button, antenna units, starter relay, wiring harnesses, connectors, battery condition, power supplies, and ground circuits for damage, corrosion, loose terminals, or low voltage. Electrical circuit testing, immobilizer verification, and CAN Bus communication checks should be completed before replacing any components.

For vehicles operating in New Zealand, confirming key authentication and battery condition before replacing electronic modules can help avoid unnecessary repair costs.

Accurately diagnosing this fault often requires manufacturer testing procedures, wiring diagrams, connector pinouts, Smart Key system schematics, immobilizer specifications, starter circuit diagrams, CAN Bus network diagrams, live data reference values, software calibration files, 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.