2010 Cadillac Truck SRX AWD V6-3.0L Page 1489

2010 Cadillac Truck SRX AWD V6-3.0L Page 1489

DTC P0420 and P0430 are Type A DTCs.

Conditions for Clearing the DTC

DTC P0420 and P0430 are Type A DTCs.

Diagnostic Aids

Inspect for the following conditions, which may cause a catalytic converter to degrade:

* An engine misfire

* High engine oil or high coolant consumption

* Retarded spark timing

* A weak or poor spark

* A lean fuel mixture

* A rich fuel mixture

* A damaged oxygen sensor or wiring harness

Reference Information

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code

(DTC) Type Definitions)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning)for scan tool information

Circuit/System Testing

1. Engine idling, observe the DTC information with a scan tool. Verify there are no HO2S or misfire DTCs set.

瀚慖f any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle) to diagnosis the applicable DTC, before proceeding with this diagnostic

procedure.

2. Verify the following conditions do not exist with the catalytic converter:

* Dents

* A severe discoloration caused by excessive temperatures

* Road damage

* An internal rattle caused by damaged catalyst substrate

* Restrictions

瀚慖f a condition is found, replace the catalytic converter.

3. Verify the following conditions do not exist with the exhaust system:

* Leaks

* Physical damage

* Loose or missing hardware

* Properly torqued HO2S

瀚慖f a condition is found, repair the exhaust system.

4. Verify the following conditions do not exist with the HO2S 2:

* A grounded wiring harness

* Damage

瀚慖f a condition is found, replace the HO2S 2.

5. If no physical condition is detected and the HO2S 2 is as active as the HO2S 1 after operating the engine at 1,500 RPM for 1 minute and then

returning to a stabilized idle, then replace the catalytic converter.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* Exhaust Leakage (See: Engine, Cooling and Exhaust/Exhaust System/Testing and Inspection/Exhaust Leakage)