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
- INSPECT ECM (+B VOLTAGE)
- Turn the ignition switch ON.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
TESTER CONNECTIONS SPECIFIED CONDITIONS CHARTTester Connections Specified Conditions +B (E47-1) - E1 (B3-1) 11 to 14 V
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
NG: Go to next step
- CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)
- Disconnect the B3 ECM connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for open)
TESTER CONNECTIONS SPECIFIED CONDITIONS CHARTTester Connections Specified Conditions E1 (B3-1) - Body ground Below 1 Ω. - Reconnect the ECM connector.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to Next Step
- INSPECT ECM (IGSW VOLTAGE)
- Turn the ignition switch ON.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
TESTER CONNECTIONS SPECIFIED CONDITIONS CHARTTester Connections Specified Conditions IGSW (E47-9) - E1 (B3-1) 11 to 14 V
OK: Go to step 6
NG: Go to next step
- CHECK FUSE (IGN FUSE)
- Remove the IGN fuse from the driver side junction block.
- Check the IGN fuse resistance.
Standard Resistance:
Below 1 Ω
- Reinstall the IGN fuse.
NG: CHECK FOR SHORT IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE
OK: Go to Next Step
- INSPECT IGNITION SWITCH ASSEMBLY
- Disconnect the A1 ignition switch connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
STANDARD RESISTANCETester Connection Switch Condition Specified Condition All Terminals LOCK 10 kΩ or higher 2 - 3 ACC Below 1 Ω 2 - 3 - 4, 6 - 7 ON Below 1 Ω 1 - 2 - 4, 6 - 7 - 8 START Below 1 Ω - Reconnect the ignition switch connector.
NG: REPLACE IGNITION SWITCH ASSEMBLY (See REMOVAL )
OK: CHECK AND REPLACE HARNESS AND CONNECTOR (BATTERY - IGNITION SWITCH, IGNITION SWITCH - ECM)
- INSPECT ECM (MREL VOLTAGE)
- Turn the ignition switch ON.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
TESTER CONNECTIONS SPECIFIED CONDITIONS CHARTTester Connections Specified Conditions MREL (E47-8) - E1 (B3-1) 11 to 14 V
NG: REPLACE ECM (See REMOVAL )
OK: Go to Next Step
- CHECK FUSE (EFI FUSE)
- Remove the EFI fuse from the engine room relay block.
- Check the EFI fuse resistance.
Standard Resistance: Below 1 Ω.
- Reinstall the EFI fuse.
NG: CHECK FOR SHORT IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE
OK: Go to Next Step
- INSPECT EFI RELAY
- Remove the EFI relay from the engine room relay block.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
TESTER CONNECTIONS SPECIFIED CONDITIONS CHARTTester Connections Specified Conditions 3 - 5 10 kΩ or higher Below 1 Ω
(when battery voltage applied to terminals 1 and 2) - Reinstall the EFI relay.
NG: REPLACE EFI RELAY
OK: Go to Next Step
- CHECK HARNESS AND CONNECTOR (EFI RELAY- ECM, EFI RELAY - BODY GROUND)
- Check the harness and connector between the EFI relay and ECM.
- Remove the EFI relay from the engine room relay block.
- Disconnect the E47 ECM connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for open)
TESTER CONNECTIONS SPECIFIED CONDITIONS CHARTTester Connections Specified Conditions EFI relay (1) - MREL (E47-8) Below 1 Ω Standard Resistance (Check for short)
TESTER CONNECTIONS SPECIFIED CONDITIONS CHARTTester Connections Specified Conditions EFI relay (1) or MREL (E47-8) - Body ground 10 kΩ or higher - Reinstall the EFI relay.
- Reconnect the ECM connector.
- Check the harness and connector between the EFI relay and body ground.
- Remove the EFI relay from the engine room relay block.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for open)
TESTER CONNECTIONS SPECIFIED CONDITIONS CHARTTester Connections Specified Conditions EFI relay (2) - Body ground Below 1 Ω - Reinstall the EFI relay.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: CHECK AND REPAIR HARNESS AND CONNECTOR (TERMINAL +B OF ECM - BATTERY POSITIVE TERMINAL)
- Check the harness and connector between the EFI relay and ECM.
NO RELATED
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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.