Display Group 038
DISPLAY GROUP 038Conditions For Three Way Catalytic Converter (TWC) Diagnostic, Banks 1 and 2
NOTES:
^ If the value of the Three Way Catalytic Converter (TWC) diagnostic is not set to "0" in display field 1 of display group 023 during the resetting of the "Readiness code" and/or a malfunction is stored in the DTC memory that relates to the TWC, diagnostic conditions (display fields 3 and 4) can be selectively checked and the diagnostic result can be read (display fields 1 and 2) using display group 038.
^ If the diagnostic conditions are met, the ECM checks the effect of the TWC (conversion) after each engine start-up by way of the front and rear heated oxygen sensors. The effect of the TWC will be displayed when display groups 029 and 030 are called up.
^ The diagnostic conditions are only met (diagnosis active) during a drive of approx. 1-1/2 to 5 min. at 50-62 mph (80-100 km/h) in 4th or 5th gear. However the diagnostic conditions are not displayed until 3 minutes after engine start-up because diagnostic is blocked until then.
^ If a malfunction (DTC) is stored in the DTC memory that relates to diagnostic conditions 1 and 2 (display fields 3 and 4), then the diagnostic conditions are not displayed. In this case, first repair malfunction, see DTC memory, checking/erasing. If a malfunction (DTC) is stored that relates to the front and rear heated oxygen sensors, the diagnostic conditions can be fulfilled, but the diagnostic result will not be OK.
^ If the effect of the TWC is recognized as OK during the first diagnostic test, the diagnosis will end. If the effect (conversion) is recognized as not OK, TWC diagnostic will continue. If the same diagnostic test is to be immediately repeated after an OK diagnosis, switch engine off then restart.
DISPLAY OVERVIEW
VAG 1551 Display Overview, Display Group 038:
NOTES ON DISPLAY FIELDS 1 & 2 :
Diagnostic Status and/or Result:
Interpreting The 2-Digit "Diagnostic Status and/or Result"
^ If the diagnostic is ended and the effect of the TWC is recognized as OK, the value "1" will be displayed for both banks in display field 2 for the corresponding TWC; the value "0" remains in display field 1.
^ if the diagnostic is ended and the effect of the TWC is recognized as not OK, the value "1" will be displayed for both banks in display field 1 for the corresponding TWC; the value "0" remains in display field 2. In this case, also read display groups 029 and 030.
NOTES ON DISPLAY FIELDS 3 & 4 :
TWC Diagnostic Conditions 1:
Interpreting The 8-Digit "TWC Diagnostic Conditions 1" Display
Value "0" = Diagnostic condition not met.
Value "1" = Diagnostic condition met.
TWC Diagnostic Conditions 2:
Interpreting The 8-Digit "TWC Diagnostic Conditions 2" Display
Value "0" = Diagnostic condition not met.
Value "1" = Diagnostic condition met.
For conditions 1 and 5: With a new TWC (less than 1250 miles/2000 km), it may take up to 1 minute longer to reach conditions 1 and 5 after all other conditions are met. If conditions 1 and 5 are not met after 1 minute (with greater than 1250 miles/2000 km), check the exhaust system for leaks between the engine and the TWC.
For condition 6: If the Evaporative Emissions (EVAP) system contains a large amount of fuel vapor, perform diagnostic using "Basic Setting" function 04 (EVAP system is switched OFF automatically during function 04).