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Home >> Toyota >> 2004 >> Matrix Base, FWD, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 139 (Engine Controls - System & Component Testing - 4-Cylinder) >> Computerized Engine Controls >> Engine Control Module Power Source Circuit >> Notes
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Engine Control Module Power Source Circuit: Notes

WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2003 Toyota Tacoma, 2003 Toyota RAV4, 2003 Toyota Prius, 2003 Toyota Matrix, and 2003 Toyota MR2. However, it is still accessible from the selected car via links, so may be relevant.
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.
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