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
Ignition "OFF"
Disconnect IAC valve connector
Ignition "ON" & Engine "OFF"
Measure voltage between terminal 2 of the valve harness connector(C15) and chassis ground
Specification : Approx. B+
Is voltage near the specified value?
YES
Go to "Signal Circuit Inspection" procedure.
NO
Check for an open or short to ground in the power supply circuit between the IAC valve and fuel pump relay. Repair as necessary and go to "Verification of Vehicle Repair" procedure
Ignition "ON" & Engine "OFF"
Measure voltage between terminal 1 of the valve harness connector(C15) and chassis ground
Specification : Approx. 0.5~0.6V
Is voltage near the specified value?
YES
Thoroughly check connectors for loose or poor connections, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure
NO
Check for short to power in signal harness
1) Ignition "OFF"
2) Disconnect ECM connectors
3) Ignition "ON"
4) Measure voltage between terminal 1 of valve harness connector(C15) and chassis ground
■ Specification : Approx. 0V
Is voltage near the specified value?
■YES
- Thoroughly check connectors for loose or poor connections, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure
■NO
- Repair short in harness and go to "Verification of Vehicle Repair" procedure.
