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 ECT sensor connector(C03).
IG KEY : ON , Engine : OFF
Measure voltage between terminal 1 of the ECT sensor harness connectorC03 and chassis ground.
Specification : Approx. 5V
Is the voltage near the specified value?
YES
Go to "Ground Circuit Inspection" procedure.
NO
Possibility of ECTS signal circuit malfunction.
Go to "Check for Open in Harness" procedure.
IG KEY : OFF , Engine : OFF
Disconnect ECT sensor connector(C03) and ECM connector.
Measure resistance between terminal 1 of the ECT sensor harness connectorC03 and 4 of the ECM harness connectorC21-2.
Specification : Approx. 0Ω
Is resistance near the specified value?
YES
Go to"Check for Short to Ground in Harness" procedure.
NO
Repair as a necessary and go to "Verification of Vehicle Repaire" procedure.
IG KEY : OFF , Engine : OFF
Disconnect ECT sensor connector(C03).
Measure resistance between terminal 1 of theECT sensor harness connectorC03 and chassis ground.
Specification : infinite( ∞ Ω)
Is the resistance near the specified value?
YES
Go to "Check for Short to Battery in Harness" procedure.
NO
Repair as necessary and go to "Verification of Vehicle Repair".
IG KEY : ON , Engine : OFF
Disconnect ECT sensor connector(C03).
Measure voltage between terminal 1 of the ECT sensor harness connectorC03 and chassis ground.
Specification : Approx. 0V
Is voltage near the specified value?
YES
Go to "Ground Circuit Inspection" procedure.
NO
Repair as a necessary and go to "Verification of Vehicle Repair" procedure.
IG KEY : ON , Engine : OFF
Disconnect ECT sensor connector(C03).
Connect jumper wire between terminals 1 and 3 of the ECT sensor harness connectorC03.
Check "ECT SENSOR" parameter on scantool.
Specification : Approx. 0V (120℃)
Is ECT 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.
