P0430
DTC P0430
GENERAL DESCRIPTION
The catalyst`s efficiency is demonstrated by its ability to oxidize CO and hydrocarbon emissions. The Powertrain Control Module (PCM) compares the output signals of the front and rear oxygen sensors to determine whether the output of the rear sensor is beginning to match the output of the front oxygen sensor. Air/fuel mixture compensation keeps the frequency of the front oxygen sensor high due to the changes from rich-to-lean composition. The catalyst causes the rear oxygen sensor to have a lower frequency. As the catalyst wears, the rear oxygen sensor`s signal trace begins to match the front oxygen sensor`s signal trace. That is because the catalyst becomes saturated with oxygen and cannot use the oxygen to convert hydrocarbon and CO into HO and CO with the same efficiency as when it was new. A completely worn catalyst shows a 100% match between the frequency of the front and rear sensors.
DTC DESCRIPTION
If the oxygen storage time for Bank 2 is lower than threshold , the PCM determines that a fault exists and a DTC is stored. MIL(Malfunction Indication Lamp) turns on.
DTC Detecting Condition:
DTC DETECTING CONDITION
MONITOR SCANTOOL DATA
1. Ignition "OFF"
2. Connect Scantool and Ignition "ON".
3. Monitor the HO2S parameters and signal waveform on Scantool.
4. Are the signal of rear HO2S and waveform the same as that of the front HO2S?
YES - Go to "System Inspection" procedure.
NO - Fault is intermittent caused by poor contact in the sensor`s and/or PCM`s connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection,bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification vehicle Repair" procedure.
SYSTEM INSPECTION
1. Check Exhaust system.
a. Visually/physically inspect the following conditions:
- Exhaust system between HO2S and Three way catalyst for air leakage
- Damage, and for loose or missing hardware:
b. Has a problem been found in any of the above areas?
YES - Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO - Go to "Component Inspection" procedure.
COMPONENT INSPECTION
1. Check Rear HO2S.
a. Visually/physically inspect the rear HO2S for the following conditions:
- Ensure that the HO2S is securely installed.(Pigtail and wiring harness not making contact with the exhaust pipe)
- Check for corrosion on terminals.
- Check for terminal tension (at the HO2S and at the PCM).
- Any road damage.
b. Has a problem been found in any of the above areas?
YES - Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO - Go to "Check TWC" as below.
2. Check TWC
a. Visually/physically inspect the three-way catalyst(TWC) converter for the following damage:
- Severe discoloration caused by excessive temperature
- Dents and holes
- Internal rattle caused by a damaged catalyst
b. Also, ensure that the TWC is a proper original equipment manufacturer part.
c. Has a problem been found?
YES - Substitute with a known - good TWC and check for proper operation. If the problem is corrected, replace TWC and go to "Verification of Vehicle Repair" procedure.
NO - Substitute with a known - good PCM and check for proper operation. If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.
NOTE: There is a memory reset function on Scantool that can erase optional parts automatically detected and memorized by PCM. After testing PCM on the vehicle, use this function to reuse the PCM on the others
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions
4. Monitor that all readiness test have been verified as "Complete".
5. Are any DTCs present?
YES - Go to the applicable troubleshooting procedure.
NO - System is performing to specification at this time.