Emissions - Converter Rattle/MIL/DTC P0420/P0422
26 11 01March 25, 2011
2023049 Supersedes T.B. V261003 dated April 20, 2010 to include the 2006 Golf 2.0L (BEV).
Vehicle Information
Condition
MIL is ON and/or Catalytic Converter is Raffling
MIL is ON, DTC P0420 and/or DTC P0422 is stored and/or catalytic converter rattling.
The expansion mat in the original part can erode prematurely, causing the converter to rattle and/or MIL ON. An improved part is available.
Repair identified after production was completed.
The above condition MAY be covered by the Catalytic Converter Limited Extended Warranty, see Warranty Policies and Procedure Manual.
Prior to replacing a catalytic converter under the Catalytic Converter Limited Extended Warranty, perform the following procedure:
^ Check the engine oil level.
Oil level MUST be correct.
If overfilled,
^ Oil level should be adjusted to proper level prior to continuing.
Adjusting oil level is NOT covered by Warranty.
^ Inspect the catalytic converter for a broken or deteriorated monolith (honeycombed interior element).
Is Catalytic Converter Rattling?
^ No: Go to interrogating DTC memory.
^ Yes: Visually inspect vehicle underbody to ensure that converter was not damaged from outside influence such as dented converter housing, etc.
Are signs of external damage to catalytic converter present?
^ Yes: The cost of replacement catalytic converter is NOT covered by warranty, proceed to interrogating DTC memory.
^ No: Proceed to interrogating DTC memory.
Interrogating DTC Memory
^ Interrogate Diagnostic Trouble Code (DTC) memory (DO NOT erase DTCs).
Required Documentation
For Analysis and Warranty purposes, obtain complete GFF logs and retain records.
Tip
Address 01 Measuring Value Block (MVB) 46
^ Check if DTC P0420 (Catalyst System Efficiency Below Threshold, Bank 1) and/or DTC P0422 (Main Catalyst Efficiency Below Threshold, Bank 1) is stored.
^ Check if DTCs from Table are stored.
Is DTC P0420 (Catalyst System Efficiency Below Threshold, Bank 1) and/or DTC P0422 (Main Catalyst
Efficiency Below Threshold, Bank 1) Stored?
If the answer is No: Are any other codes from the table stored?
^ Yes: Proceed to "DTCs in table are stored" (see below).
^ No: Are signs of external damage to catalytic converter present?
^ Yes: NOT covered by warranty. Return vehicle to the customer without replacing catalytic converter.
^ No: Proceed to Replace catalytic converter" (see below).
If the answer is Yes: Are any other codes from the table stored?
^ Yes: Proceed to "DTCs in table are stored" (see below).
^ No: Proceed to Replace catalytic converter" (see below).
DTCs in Table are Stored:
NOTE
Once the cause of the DTC(s) stored in the Table are corrected, proceed to "All other DTCs Stored Are Corrected".
All Other DTCs Stored Are Corrected:
Is catalytic converter rattling?
^ Yes: Proceed to "Replace catalytic converter" (see below).
^ No: Erase all DTCs and attempt set readiness code
Will Readiness Code Set?
^ Yes: Return vehicle to the customer without replacing catalytic converter.
^ No: Proceed to "Replace Catalytic Converter" (see below).
If vehicle was returned to the Customer (without converter replacement) and Customer returns with DTC P0420 and/or DTC P0422 stored again:
^ Replace catalytic converter
Erase all DTC(s) and set readiness code.
Warranty
Required Parts and Tools
When replacing any catalyst, the VIN may be required to ensure the correct part is ordered (check with your Parts Dept.).
Parts submission:
If catalytic converter is on parts submission:
^ Attach copies of all supporting documentation (including print-outs) required when sending parts to Warranty Parts Return Center.
Tip
Additional Information
All part and service references provided in this Technical Bulletin are subject to change and/or removal. Always check with your Parts Dept. and Repair Manuals for the latest information.