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 "Signal Circuit Inspection" procedure.
IG KEY : OFF , Engine : OFF
Disconnect IAT sensor connector(C29).
IG KEY : ON , Engine : OFF
Measure voltage between terminal 3 of the IAT sensor harness connectorC29 and chassis ground.
Specfication: Approx. 5V
Is the voltage near the specified value?
YES
Go to "Ground Circuit Inspection" procedure.
NO
Possibility of IAT signal circuit malfunction.
Go to "Check for Open in Harness" procedure.
IG KEY : OFF , Engine : OFF
Disconnect IAT sensor connector(C29) and ECM connector.
Measure resistance between terminal 3 of the IAT sensor harness connectorC29 and 2 of the ECM harness connectorC22-4.
Specfication: Approx. 0Ω
Is resistance near the specified value?
YES
Go to next step "Check for Short to Battery in Harness" procedure.
NO
Repair as necerssary and go to "Verification of Vehicle Repair" procedure.
IG KEY : ON , Engine : OFF
Disconnect IAT sensor connector(C29) and ECM connector.
Measure voltage between terminal 3 of the IAT sensor harness connectorC29 and chassis ground.
Specfication: Approx. 0V
Is voltage near the specified value?
YES
Go to " Ground Circuit Inspection" procedure.
NO
Repair as necerssary and go to "Verification of Vehicle Repair" procedure.
IG KEY : ON , Engine : OFF
Disconnect IAT sensor connector(C29).
Connect jumper wire between terminals 3 and 4 of the IAT sensor harness connectorC29.
Check "IAT SENSOR" parameter on scantool.
Specification : Approx. 0V (119℃)
Is IAT sensor’s signal near the specified value?
YES
Go to " Component Inspection" procedure.
NO
Repair open in harness, Go to "Verification of Vehicle Repair" procedure.
