Signal Missing. Permanent Fault

Signal missing. Permanent fault

Checking the heated oxygen sensor (HO2S)








- Ignition off
- Disconnect the connectors for the front (ECM-18) and rear (ECM-1C) heated oxygen sensor (HO2S).
Check the connectors for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault.
Remedy as necessary.





Was a fault detected?

Yes - Verification

No - Checking the power cable

-------------------------------------------------

Checking the power cable




- Ignition off.
Connect a voltmeter between connector terminal 1 on the heated oxygen sensor (HO2S) (engine control module (ECM) side) and ground.
Ignition on.









The voltmeter should read battery voltage for 2 seconds immediately the ignition is switched on.

OK - Checking the signal cable

Not OK - Checking the power cable

-------------------------------------------------

Checking the signal cable




- Ignition on.
Connect a voltmeter between connector terminal 2 on the heated oxygen sensor (HO2S) (engine control module (ECM) side) and ground.









The voltmeter should read 3-5 V.

OK - Defective heated oxygen sensor (HO2S)

Not OK - Checking the signal cable

-------------------------------------------------

Defective heated oxygen sensor (HO2S)
Try a new heated oxygen sensor (HO2S) according to Replace the front heated oxygen sensor (HO2S) Replace The Front Heated Oxygen Sensor (HO2S).

Select Continue.

Continue - Verification

-------------------------------------------------

Checking the power cable




- Ignition off.
Check the cable between heated oxygen sensor (HO2S) connector terminal 1 (control module side) and system relay 2/14 base # 3 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault.
Remedy as necessary.













Select Continue.

Continue - Verification

-------------------------------------------------

Checking the signal cable




- Ignition off.
Check the cable between heated oxygen sensor (HO2S) connector terminal 2 (control module side) and engine control module (ECM) connector terminal 63 (ECM-18) or terminal 65 (ECM-1C) for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault.
Remedy as necessary.













Select Continue.

Continue - Verification

-------------------------------------------------

Verification








- Reconnect the connectors, reinstall components etc.
- Connect VCT 2000
- Start the engine.
Check whether diagnostic trouble code (DTC) ECM-18 or ECM-1C has changed status to intermittent.





Is diagnostic trouble code (DTC) ECM-18 or ECM-1C intermittent?

Yes - FAULT FOUND

No - No Fault FoundFault-tracing information

-------------------------------------------------

Fault-tracing information




Information

Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Do you want to exit fault-tracing?

Yes - FAULT-TRACING FAILED

No - Attempt New Test

------------------------

FAULT-TRACING FAILED - No Fault Found

Attempt New Test - Checking the heated oxygen sensor (HO2S)

-------------------------------------------------