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.
Diagnostic Procedure
- INSPECTION START
Start engine.
Is engine running?
Yes or No
Yes: GO TO 8.
No: GO TO 2.
- CHECK ECM POWER SUPPLY CIRCUIT-I
- Turn ignition switch OFF and then ON.
- Check voltage between ECM terminal 93 and ground with CONSULT-III or tester.
Voltage: Battery voltage
OK or NG
OK: GO TO 4.
NG: GO TO 3.
- DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors M6, E19
- Harness for open or short between ECM and ignition switch
: Repair open circuit or short to ground or short to power in harness or connectors.
- CHECK GROUND CONNECTIONS
- Turn ignition switch OFF.
- Loosen and retighten ground screws on the body.
Refer to "GROUND INSPECTION ".
OK or NG
OK: GO TO 5.
NG: Repair or replace ground connections.
- CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-I
- Disconnect ECM harness connector.
- Check harness continuity between ECM terminals 12, 16, 107, 108, 111, 112 and ground.
Refer to WIRING DIAGRAM .
Continuity should exist.
- Also check harness for short to power.
OK or NG
OK: GO TO 7.
NG: GO TO 6.
- DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors F10, E17
- Harness for open or short between ECM and ground
: Repair open circuit or short to power in harness or connectors.
- CHECK ECM POWER SUPPLY CIRCUIT-II
- Reconnect ECM harness connector.
- Turn ignition switch ON.
- Check voltage between IPDM E/R terminal 3 and ground with CONSULT-III or tester.
Voltage: Battery voltage
OK or NG
OK: Go to "IGNITION SIGNAL ".
NG: GO TO 8.
- CHECK ECM POWER SUPPLY CIRCUIT-III
- Turn ignition switch OFF and wait at least 10 seconds.
- Turn ignition switch ON and then OFF.
- Check voltage between ECM terminal 105 and ground with CONSULT-III or tester.
Voltage: After turning ignition switch OFF, battery voltage will exist for a few seconds, then drop approximately 0V.
OK or NG
OK: GO TO 14.
NG (Battery voltage does not exist.): GO TO 9.
NG (Battery voltage exists for more than a few seconds.): GO TO 11.
- CHECK ECM POWER SUPPLY CIRCUIT-IV
- Turn ignition switch OFF and wait at least 10 seconds.
- Check voltage between ECM terminal 24 and ground with CONSULT-III or tester.
Voltage: Battery voltage
OK or NG
OK: GO TO 10.
NG: GO TO 11.
- CHECK ECM POWER SUPPLY CIRCUIT-V
- Disconnect ECM harness connector.
- Disconnect IPDM E/R harness connector E43.
- Check harness continuity between ECM terminal 105 and IPDM E/R terminal 4.
Refer to WIRING DIAGRAM .
Continuity should exist.
- Also check harness for short to ground and short to power.
OK or NG
OK: GO TO 17.
NG: Repair open circuit or short to ground or short to power in harness or connectors.
- CHECK ECM POWER SUPPLY CIRCUIT-VI
- Disconnect ECM harness connector.
- Disconnect IPDM E/R harness connector E43.
- Check harness continuity between ECM terminal 24 and IPDM E/R terminal 7.
Refer to WIRING DIAGRAM .
Continuity should exist.
- Also check harness for short to ground and short to power.
OK or NG
OK: GO TO 13.
NG: GO TO 12.
- DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E3, F2
- Harness for open or short between ECM and IPDM E/R
: Repair open circuit or short to ground or short to power in harness or connectors.
- CHECK 20A FUSE
- Disconnect 20A fuse from IPDM E/R.
- Check 20A fuse.
OK or NG
OK: GO TO 17.
NG: Replace 20A fuse.
- CHECK GROUND CONNECTIONS
Loosen and retighten ground screws on the body.
Refer to "GROUND INSPECTION ".
OK or NG
OK: GO TO 15.
NG: Repair or replace ground connections.
- CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-II
- Disconnect ECM harness connector.
- Check harness continuity between ECM terminals 12, 16, 107, 108, 111, 112 and ground.
Refer to WIRING DIAGRAM .
Continuity should exist.
- Also check harness for short to power.
OK or NG
OK: GO TO 17.
NG: GO TO 16.
- DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors F10, E17
- Harness for open or short between ECM and ground
: Repair open circuit or short to power in harness or connectors.
- CHECK INTERMITTENT INCIDENT
Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".
OK or NG
OK: Replace IPDM E/R. Refer to "IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM) ".
NG: Repair open circuit or short to power in harness or connectors.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.
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