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.
ECM Power Source Circuit [06/2016 - 03/2017]: Procedure
- INSPECT ECM (POWER SOURCE VOLTAGE)
- Turn the ignition switch to ON.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition A34-6 (+B) - A36-4 (E01) Ignition switch ON 12 to 14 V A33-1 (+B2) - A36-4 (E01) Ignition switch ON 12 to 14 V TEXT IN ILLUSTRATION*a Component with harness connected
(ECM)
Result:
NG
See step 4
Result:
OK
See step 2
- CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)
- Disconnect the ECM connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A36-4 (E01) - Body ground Always Below 1 Ω
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 3
- INSPECT ECM (IGSW TERMINAL VOLTAGE)
- Turn the ignition switch to ON.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition A33-27 (IGSW) - A36-4 (E01) Ignition switch ON 10 to 13 V TEXT IN ILLUSTRATION*a Component without harness connected
(ECM)
Result:
OK
REPLACE ECM
(Refer to REMOVAL [06/2016 - ] )
Result:
NG
See step 8
- INSPECT ECM (SSHUT TERMINAL VOLTAGE)
- Turn the ignition switch to ON.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition A35-13 (SSHUT) - A36-4 (E01) Ignition switch ON approximately 0 V TEXT IN ILLUSTRATION*a Component without harness connected
(ECM)
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 5
- INSPECT RELAY (EFI MAIN1)
- Inspect the EFI MAIN1 relay (Refer to PROCEDURE - Step 1 ).
Result:
NG
REPLACE RELAY (EFI MAIN1)
Result:
OK
See step 6
- CHECK HARNESS AND CONNECTOR (EFI MAIN1 RELAY - ECM)
- Remove the EFI MAIN1 relay from the engine room relay block assembly.
- Disconnect the ECM connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for open)
Tester Connection Condition Specified Condition EFI MAIN1 relay terminal 1 - A35-13 (SSHUT) Always Below 1 Ω EFI MAIN1 relay terminal 3 - A34-6 (+B) Always Below 1 Ω EFI MAIN1 relay terminal 3 - A33-1 (+B2) Always Below 1 Ω Standard Resistance (Check for short)
Tester Connection Condition Specified Condition EFI MAIN1 relay terminal 1 or A35-13 (SSHUT) - Body ground Always 10 kΩ or higher EFI MAIN1 relay terminal 3, A34-6 (+B) or A33-1 (+B2) - Body ground Always 10 kΩ or higher
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 7
- INSPECT TERMINAL VOLTAGE (EFI MAIN1 RELAY)
- Remove the EFI MAIN1 relay from the engine room relay block assembly.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition EFI MAIN1 relay terminal 2 - Body ground Always 11 to 14 V EFI MAIN1 relay terminal 5 - Body ground Always 11 to 14 V TEXT IN ILLUSTRATION*1 Engine Room Relay Block Assembly *2 EFI MAIN1 Relay Terminal
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 8
- Remove the EFI MAIN1 relay from the engine room relay block assembly.
- CHECK HARNESS AND CONNECTOR (IG2 RELAY - ECM)
- Remove the IG2 relay from the engine room relay block assembly.
- Disconnect the ECM connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for open)
Tester Connection Condition Specified Condition IG2 relay terminal 3 - A33-27 (IGSW) Always Below 1 Ω IG2 relay terminal 1 - Body ground Always Below 1 Ω Standard Resistance (Check for short)
Tester Connection Condition Specified Condition IG2 relay terminal 3 or A33-27 (IGSW) - Body ground Always 10 kΩ or higher
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 9
- INSPECT RELAY (IG2)
- Inspect the IG2 relay (Refer to PROCEDURE - Step 4 ).
Result:
NG
REPLACE RELAY (IG2)
Result:
OK
See step 10
- INSPECT TERMINAL VOLTAGE (IG2 RELAY)
- Remove the IG2 relay from the engine room relay block assembly.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition IG2 relay terminal 5 - Body ground Always 11 to 14 V TEXT IN ILLUSTRATION*1 Engine Room Relay Block Assembly *2 IG2 Relay Terminal
Result:
OK
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
NG
See step 11
- Remove the IG2 relay from the engine room relay block assembly.
- CHECK HARNESS AND CONNECTOR (IG2 RELAY - IGNITION OR STARTER SWITCH ASSEMBLY)
- Remove the IG2 relay from the engine room relay block assembly.
- Disconnect the ignition or starter switch assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for open)
Tester Connection Condition Specified Condition IG2 relay terminal 2 - D55-6 (IG2) Always Below 1 Ω Standard Resistance (Check for short)
Tester Connection Condition Specified Condition IG2 relay terminal 2 or D55-6 (IG2) - Body ground Always 10 kΩ or higher
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 12
- INSPECT IGNITION OR STARTER SWITCH ASSEMBLY
- Inspect the ignition or starter switch assembly (Refer to INSPECTION [06/2016 - ] ).
Result:
OK
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
NG
REPLACE IGNITION OR STARTER SWITCH ASSEMBLY
(Refer to REMOVAL [06/2016 - 03/2017] )
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.