Display Group 035

DISPLAY GROUP 035
Voltage Signals Of Front And Rear Heated Oxygen Sensors (HO2S).

DISPLAY OVERVIEW

VAG 1551 Display Overview, Display Group 035:

NOTES ON DISPLAY FIELDS 3 & 4 :
^ Wait at least 50 seconds after the O2S heater is switched ON before evaluating the voltage signal for O2S 1 behind TWC (bank 1) and/or O2S 2 behind TWC (bank 2), see display group 034.
^ With engine cold and ignition ON, a voltage signal of 0.400 volts is displayed in all 4 display fields. With engine hot and ignition ON, a voltage signal of 0.000 volts is displayed in display fields 3 and 4 after approximately 5 minutes after engine is switched OFF. A deviation may be caused by residual gases in the exhaust system.
^ The voltage signal of the oxygen sensors behind TWC's must be between approx. 0.5-0.6 volts if the TWC is working adequately (conversion). During a deceleration fuel shut-off, the voltage signal must be constantly less than 0.1 volt. During Wide Open Throttle (WOT) operation with WOT enrichment, the voltage signal must be greater than 0.6 volts.
^ If a WOT condition exists (signal voltage greater than 0.6 volts) with a new TWC (less than 3100 mile, 5000 km mileage) after a prior deceleration fuel shut-off (voltage signal less than 0. 1 volt), the transition from lower to higher voltage may be delayed up to 10 seconds. If there is uniform acceleration in the partial load range after a prior deceleration fuel shut-off the transition from lower to higher voltage can be delayed up to 3 min.