SC300 & SC400
- Access ECM under front of carpet on passenger side of vehicle. Turn ignition on. Backprobing connector, connect DVOM negative lead to terminal No. 17 (White/Red wire) at ECM E16 connector and positive lead to terminal No. 16 (Black/Red wire) at ECM E19 connector. See Fig 1. If 9-14 volts is present, ECM power circuit is okay. Diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
If 9-14 volts is not present, go to next step.
- Check for an open circuit in White/Red wire between ground and terminal No. 17 at ECM E16 connector. See appropriate wiring diagram in
WIRING DIAGRAMS article. Repair as necessary. If wiring is okay, go to next step.
- Measure voltage between chassis ground and terminal No. 9 (Black/Orange wire) at ECM E19 connector. If 9-14 volts is present, go to step 5. If 9-14 volts is not present, check IGN fuse in junction box No. 1 behind left kick panel.
- If fuse is blown, repair cause of blown fuse. If fuse is okay, check ignition switch. See
STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. Replace ignition switch as necessary and retest. If ignition switch is okay, repair open circuit between battery and ignition switch, or between ignition switch and ECM.
- Turn ignition on. Measure voltage between chassis ground and terminal No. 10 (Black/Yellow wire) at ECM E19 connector. If 9-14 volts is not present, replace ECM. If 9-14 volts is present, check EFI fuse located in engine compartment fuse/relay box at left front of engine compartment. If fuse is okay, go to next step. If fuse is blown, repair cause of blown fuse.
- Check EFI main relay located in engine compartment fuse/relay box at left front of engine compartment. See RELAYS under MOTORS, RELAYS & SOLENOIDS. If EFI main relay is okay, check circuit between chassis ground and terminal No. 10 at ECM E19 connector. See appropriate wiring diagram in
WIRING DIAGRAMS article. Repair as necessary. If circuit is okay, repair circuit between battery and EFI fuse.
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