Upstream catalyst temperature in the EEC system
Disconnect the sensor and measure the resistance. If the temperature is between 10 and 30 degC, the measured resistance should be 207 - 222 ohm. If the value differs, replace the sensor.See if there is any visible fault on the upstream catalyst temperature sensor, wiring or connectors.For engines with NOx-control software, confirmation of repair requires:- Turn the ignition off, wait at least 90 s- Turn the ignition on If the fault is remedied, the DTC should now be passive.
What you'll see
No driver-visible symptom recorded.
System reaction
The EEC system will not inject any urea, which leads to higher emissions. If the voltage is outside permitted range, the control unit for the EEC system uses a pre-programmed value of 0 degC (parameter ACTU_T_RVAL_CW).For engines with NOx-control software, this DTC is classed as a type D failure.
Diagnostic depth
The voltage has been below 0.40 V (below -50 degC), i.e. the upstream catalyst temperature was above its upper limit.(Refer BOSCH SW-specification Y281S01334-VC0 for more details. Error path: ep00_s_def_ouw.8, actu_s_def_ouc.1.)
Short circuit in the upstream catalyst temperature sensor circuit.