Many malfunctions in the electrical system are caused by poor harness(s) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Check the following conditions:
Check for damaged harness and terminals: contact resistance, oxidation, bent or broken terminals.
Check for poor connection between ECM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection
Use a suitable male pin to ensure that contact in sockets is good. The pin should remain in position when pulled gently.
Has a problem been found?
YES
Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO
Go to "Power Circuit Inspection" procedure.
IG KEY : ON , Engine : OFF
Disconnect ISCA connector.
Measure voltage between terminal 2 of the ISCA harness connectorC14 and chassis ground.
[Specification] Approx.B+
Is the voltage near the specified value?
YES
Go to "Control Circuit Inspection" procedure.
NO
Repair open or short to ground in harness between main relay and ISCA.
Then go to "Verification of Vehicle Repair" procedure.
IG KEY : OFF , Engine : OFF
Disconnect ISCA connector and ECM connector.
Measure resistance between terminal 1 of the ISCA harness connector and 17 of the ECM harness connectorC22-1.
Measure resistance between terminal 3 of the ISCA harness connector and 4 of the ECM harness connectorC22-1.
[Specification] Approx.0Ω
Is the resistance near the specified value?
YES
Go to "Check for Short to Ground" procedure.
NO
Repair open in harness, Go to "Verification of Vehicle Repair" procedure.
IG KEY : OFF , Engine : OFF
Disconnect ISCA connector.
Measure resistance between terminal 1 of the ISCA harness connector and chassis ground
Measure resistance between terminal 3 of the ISCA harness connector and chassis ground
[Specification] infinite(∞Ω)
Does the resistance indicate open?
YES
Go to "Check for Short to Battery" procedure.
NO
Repair short to chassis ground in harness, Go to "Verification of Vehicle Repair" procedure.
IG KEY : ON , Engine : OFF
Disconnect ISCA connector.
Measure voltage between terminal 1 of the ISCA harness connector and chassis ground
Measure voltage between terminal 3 of the ISCA harness connector and chassis ground
[Specification] Approx.0V
Is the voltage near the specified value?
YES
Go to "Component Inspection" procedure.
NO
Repair short to battery in harness, Go to "Verification of Vehicle Repair" procedure.
