MG ZS (Gen2) Fuel Pump Circuit Fault

A Fuel Pump Circuit Fault indicates that the Engine Control Module (ECM) has detected an electrical problem within the fuel pump control circuit. Rather than indicating a mechanical failure of the fuel pump itself, this fault points to an issue affecting the electrical supply, control, or communication between the ECM and the fuel pump assembly. The fault may involve the fuel pump relay, fuse, wiring harness, connectors, grounds, or the fuel pump control circuit. If the ECM cannot properly operate or monitor the fuel pump, fuel delivery may be interrupted, resulting in poor engine performance or a no-start condition. This fault applies to the MG ZS Gen2 (ZS11 platform), introduced from 2024 onwards.

Symptoms

  • Check Engine Light illuminated
  • Engine cranks but fails to start
  • Extended cranking before starting
  • Engine stalls unexpectedly
  • Poor acceleration
  • Loss of engine power
  • Intermittent engine operation
  • Reduced fuel pressure
  • Fuel pump does not prime when the ignition is switched on
  • Fuel pump-related DTCs stored

Possible Causes

  • Faulty fuel pump relay
  • Blown fuel pump fuse
  • Open circuit in the fuel pump wiring
  • Short circuit to ground or battery voltage
  • High resistance in the fuel pump circuit
  • Loose, damaged, or corroded electrical connectors
  • Poor fuel pump ground connection
  • Damaged wiring harness
  • Faulty fuel pump control module (where equipped)
  • Internal fuel pump electrical failure
  • Low battery or charging system voltage
  • Faulty Engine Control Module (ECM) (rare)

Diagnosis

Diagnosis begins by confirming any stored Diagnostic Trouble Codes (DTCs) and reviewing freeze-frame and live data using a compatible diagnostic scan tool. The technician should verify whether the ECM is commanding fuel pump operation and inspect the fuel pump fuse, relay, and associated power distribution circuits. Battery voltage should be confirmed before testing the fuel pump power supply, ground circuits, and control signals using a multimeter or oscilloscope. Wiring harnesses and connectors should be inspected for corrosion, loose terminals, damaged insulation, or evidence of overheating. Circuit continuity, voltage drop, and resistance tests should be performed to identify opens, shorts, or excessive resistance. If the electrical circuit passes inspection, the fuel pump should be tested under load to verify proper current draw and operation. Manufacturer diagnostic procedures may also include actuator tests, fuel pump command tests, ECM output verification, and fuel pressure testing to determine whether the fault is electrical or mechanical.

For vehicles operating in New Zealand, following OEM diagnostic procedures helps accurately distinguish between a wiring fault, relay failure, poor electrical connection, fuel pump electrical failure, control circuit problem, or ECM fault before replacing expensive fuel system components.

Accurately diagnosing this fault often requires manufacturer testing procedures, wiring diagrams, fuel pump circuit schematics, connector pinouts, relay and fuse layouts, fuel pressure specifications, electrical load testing procedures, voltage drop specifications, ECM control strategies, 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.