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Ecu Power Source Circuit

  1. Check condition of DOME and DOOR fuses. DOME fuse is located in engine compartment junction block, on left side of engine compartment. DOOR fuse is located in instrument panel junction block, under left side of instrument panel. If fuses are okay, go to next step. If fuse(s) are faulty, check for short in circuit between fuse(s) and anti-theft ECU. See WIRING DIAGRAMS . Repair short in harness or connectors as necessary. Replace appropriate fuse and retest system operation.
  2. Turn ignition off. Disconnect anti-theft ECU connectors T3 and T4. Turn ignition on. Using a voltmeter, measure voltage between ECU 22-pin connector T4 terminal No. 11 (Red/Yellow wire) and ECU 12-pin connector T3 terminal No. 7 (White/Black wire). See Figure. See WIRING DIAGRAMS . Also, measure voltage between ECU 12-pin connector T3 terminal No. 1 (Blue/White wire) and ECU connector T3 terminal No. 7 (White/Black wire). If voltages are not 10-14 volts, go to next step. If voltages are 10-14 volts, go to next test listed in SYMPTOM DIAGNOSIS  table under TROUBLE SHOOTING.
  3. Check circuits for faults between body ground and anti-theft ECU. See WIRING DIAGRAMS . Repair or replace as necessary. If circuits are okay, check and repair circuits between body control ECU and battery. Retest system operation.
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