Sunday, January 23, 2022

2010 Cadillac Truck SRX FWD V6-3.0L Page 1489

2010 Cadillac Truck SRX FWD 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)