Engine Control Module Power Source Circuit: Notes

CAUTION: If Engine Control Module (ECM) replacement is instructed in the following testing, always ensure ECM wiring harness electrical connector and ground circuit are okay. If either are defective, repair and repeat testing to confirm ECM malfunction.

NOTE: When performing test for Engine Control Module (ECM) power source circuit, it may be necessary to check wiring harness and components connected to a specified fuse, or check wiring harness and electrical connectors between EFI main relay and battery. For additional wiring information for fuse and power supply circuit, see POWER DISTRIBUTION article in WIRING DIAGRAMS.