MG ZS (Gen2) Smart Key Not Detected

A Smart Key Not Detected fault indicates that the vehicle is unable to detect or authenticate the proximity key required for keyless entry and push-button starting. The Smart Key system uses the Body Control Module (BCM), Smart Key Control Module, immobilizer, antenna units, and key fob to establish secure communication. If communication is interrupted due to a key, antenna, wiring, battery, or control module fault, the vehicle may prevent starting or display a warning message. This fault applies to the MG ZS Gen2 (ZS11 platform), introduced from 2024 onwards.

Symptoms

  • Smart Key Not Detected message displayed
  • Engine will not start using the start button
  • Keyless entry not functioning
  • Keyless locking or unlocking inoperative
  • Push-button start unavailable
  • Immobilizer warning light illuminated
  • Multiple warning messages displayed
  • Intermittent key detection
  • Vehicle starts only when the key is held near the backup detection area
  • Smart Key-related Diagnostic Trouble Codes (DTCs) stored

Possible Causes

  • Flat smart key battery
  • Faulty smart key fob
  • Smart key not programmed correctly
  • Faulty interior or exterior key antenna
  • Faulty Smart Key Control Module
  • Faulty Body Control Module (BCM)
  • Immobilizer system fault
  • Damaged wiring harness
  • Loose or corroded electrical connectors
  • CAN Bus communication fault
  • Low vehicle battery voltage
  • Software or programming fault

Diagnosis

Diagnosis begins by retrieving all stored Diagnostic Trouble Codes (DTCs) from the Smart Key system, Body Control Module (BCM), immobilizer, and other related control modules using a compatible diagnostic scan tool. Live data should be reviewed to verify key detection, antenna operation, authorization status, and communication between the affected modules.

The technician should inspect the smart key battery, antenna units, wiring harnesses, connectors, power supplies, and ground circuits for damage, corrosion, loose terminals, or water intrusion. Key programming, immobilizer authorization, electrical circuit testing, and CAN Bus communication checks should be completed before replacing any components.

For vehicles operating in New Zealand, verifying the condition of the key fob battery and confirming key programming 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 and immobilizer schematics, BCM communication diagrams, key programming procedures, 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.