Without CONSULT

^ The three-way catalyst function has one trip detection logic.

OVERALL FUNCTION CHECK
This procedure can be used for checking the overall function of the three way catalyst. During this check, a Diagnostic Trouble Code (DTC) might not be confirmed.
1) Start engine and warm it up sufficiently.




2) Set voltmeter probes between Engine Control Module (ECM) terminals "46" (front heated oxygen sensor signal) and "43" (engine ground), and ECM terminals "52" (rear heated oxygen sensor signal) and "43" (engine ground).
3) Keep engine speed at 2,000 rpm constant under no load.
4) Make sure that the voltage switching frequency (high & low) between ECM terminals "52" and "43" is much less than that of ECM terminals "46" and "43".

Switching frequency ratio =

Rear heated oxygen sensor voltage switching frequency
Front heated oxygen sensor voltage switching frequency

This ratio should be less than 0.40 for A/T models and 0.37 for M/T models.
If the ratio is greater than the above value, it means three way catalyst does not operate properly.

NOTE: If the voltage at terminal "46" does not switch periodically more than 5 times within 10 seconds at step 3, perform TROUBLE DIAGNOSIS FOR DTC 33 (Front heated oxygen sensor) first.