Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Inspection Procedure
- Check voltage between terminals +B and E1 or ECM connectors.
PREPARATION:
- Turn the ignition switch to ON.
CHECK:
Measure the voltage between the terminals +B and E1 of the ECM connectors.
OK:
Voltage: 9 to 14 V
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- OK: Proceed to next circuit inspection shown in problem symptoms table (See PROBLEM SYMPTOMS TABLE ).
- NG: Go to next step.
- Check for open in harness and connectors between terminal E1 of ECM connector and body ground (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE
).
- NG: Repair or replace harness or connector.
- OK: Go to next step.
- Check voltage between terminal IGSW of ECM connector and body ground.
PREPARATION:
- Turn the ignition switch to ON.
CHECK:
Measure the voltage between the terminal IGSW of the ECM connector and body ground.
OK:
Voltage: 9 to 14 V
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- NG: Go to step 8 .
- OK: Go to next step.
- Inspect IG2 fuse.
PREPARATION:
Remove the IG2 fuse from the FL block and J/B No. 1.
CHECK:
Measure the resistance of the IG2 fuse.
OK:
Below 1 Ω
- NG: Check for short in all harness and components connected to IG2 fuse.
- OK: Go to next step.
- Check IG2 relay (See IGNITION RELAY (NO. 2)
).
- NG: Replace IG2 relay.
- OK: Go to next step.
- Inspect AM2 fuse.
PREPARATION:
Remove the AM2 fuse from the FL block and J/B No. 1.
CHECK:
Measure the resistance of the AM2 fuse.
OK:
Below 1 Ω
- NG: Check for short in all harness and components connected to AM2 fuse (See Figure )
- OK: Go to next step.
- Check ignition switch (See IGNITION SWITCH AND KEY UNLOCK WARNING SWITCH
).
- NG: Replace ignition switch.
- OK: Check and repair harness and connectors between battery and ignition switch, and ignition switch and ECM.
- Check voltage between terminal MREL of ECM connector and body ground.
PREPARATION:
- Turn the ignition switch to ON.
CHECK:
Measure the voltage between the terminal MREL of the ECM connector and body ground.
OK: Voltage: 9 to 14 V
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- NG: Replace ECM (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
- OK: Go to next step.
- Check EFI1 fuse (See step 1 in INSPECTION PROCEDURE).
- NG: Check for short in all harness and components connected to EFI1 fuse (See Figure )
- OK: Go to next step.
- Check EFI MAIN relay (Marking: EFI) (See INSPECTION
).
- NG: Replace EFI MAIN relay.
- OK: Go to next step.
- Check for open and short in harness and connectors between terminal MREL of ECM and body ground (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE
).
- NG: Repair or replace harness or connector.
- OK: Check and repair harness or connector between EFI1 fuse and battery.
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.