Code 51 & 52 - Faulty ECM Ram/ROM

NOTE: See appropriate wiring diagram in WIRING DIAGRAMS article for terminal and connector identification.

NOTE: Test number refers to number on diagnostic chart.

1. Before replacing ECM, check circuit connections:
   • Disconnect ECM harness connectors. Inspect all terminals and repair as necessary.
   • Reconnect ECM harness connectors, and road test vehicle.
   • Check for codes. If condition persists or code reappears, replace ECM.

Fig 1: Code 51, 52 - Diagnostic Flowchart

Courtesy of ISUZU MOTOR CO.