P0430

ON BOARD DIAGNOSIS LOGIC
ECM monitors the switching frequency ratio of heated oxygen sensor 1 (front) and 2 (rear).

A three way catalyst with high oxygen storage capacity will indicate a low switching frequency of heated oxygen sensor 2 (rear). As oxygen storage capacity decreases, the heated oxygen sensor 2 (rear) switching frequency will increase.

When the frequency ratio of heated oxygen sensor 1 (front) 2 (rear) approaches a specified limit value, the three way catalyst malfunction is diagnosed.







DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE

CAUTION: Always drive vehicle at a safe speed.

NOTE: If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.

With Consult
1. Start engine and drive vehicle at a speed of more than 70 km/h (43 MPH) for 2 consecutive minutes.
2. Stop vehicle with engine running.
3. Set "MANU TRIG" and "HI SPEED", then select "HO2S1 (B1) (B2)", "HO2S1 (B1) (B2)", "HO2S1 MNTR (B1) (B2)", "HO2S1 MNTR (B1) (B2)" in "DATA MONITOR" mode with CONSULT-II.
4. Touch "RECORD" on CONSULT-II screen with engine speed held at 2,000 rpm constantly under no load.
5. Make sure that the switching frequency between "RICH" and "LEAN" of "HO2S1 MNTR (B1) (B2)" is much less than that of "HO2S1 MNTR (B1) (B2)" as shown.

Switching frequency ratio =
Heated oxygen sensor 2 (rear) switching frequency / Heated oxygen sensor 1 (front) switching frequency

This ratio should be less than 0.75.
If the ratio is greater than above, the three way catalyst is not operating properly.

If the "HO2S1 MNTR (B1) (B2)" does not indicate "RICH" and "LEAN" periodically more than 5 times within 10 seconds at step 4, perform TROUBLE DIAGNOSES FOR DTC P0133 first.

If the result is NG, go to "DIAGNOSTIC PROCEDURE".
If the result is OK, go to following step.

6. Select "AUTO TRIG" in "DATA MONITOR" mode with CONSULT-II.
7. Drive vehicle at a speed more than 84 to 96 km/h (52 to 60 MPH) with D position ("OD" ON) for at least 10 consecutive minutes.
(Drive the vehicle in an area where vehicle speed and accelerator pressure can be held steady and constant.) If the result is NG, go to "DIAGNOSTIC PROCEDURE".
8. Select "SRT STATUS" in "DTC CONFIRMATION" mode with CONSULT-II.
9. Verify that "CATALYST" is "CMPLT".
If not "CMPLT", repeat the test from step 3.
10. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

OR




OVERALL FUNCTION CHECK
Use this procedure to check the overall function of the three way catalyst.

During this check, a DTC might not be confirmed.

Without Consult
1. Start engine and drive vehicle at a speed of more than 70 km/h (43 MPH) for 2 consecutive minutes.
2. Stop vehicle with engine running.
3. Set voltmeters probes between ECM terminals (82) (B2), (83) (B1) (sensor signal front) and ground (89) (B2), (90) (B1)
(sensor signal rear) and ground.

4. Keep engine speed at 2,000 rpm constant under no load.
5. Make sure that the voltage switching frequency (high & low) between ECM terminals (89) and ground is much less than that of ECM terminals (82) and ground (right bank). Or (90) and ground is much less than that of the terminals (83) and ground (left bank).

Switching frequency ratio =
Heated oxygen sensor 2 (rear) voltage switching frequency / Heated oxygen sensor 1 (front) voltage switching frequency
This ratio should be less than 0.75.
If the ratio is greater than above, it means three way catalyst does not operate properly.

NOTE: If the voltage at terminal (82) or (83) does not switch periodically more than 5 times within 10 seconds at step 4, perform TROUBLE DIAGNOSIS FOR DTC P0130 or P0150 first.

6. If NG, go to "DIAGNOSTIC PROCEDURE".




DIAGNOSTIC PROCEDURES