T8 / P0140 00
Read the instructions below then
start the fault diagnostic procedure.
Symptom: Fault indicator lamp (for further information see WIS Fault diagnosis, general)
O2S Circuit. No Activity Detected. Sensor 2.
Fault symptom
Fault indicator lamp (for further information see WIS Fault diagnosis, general)
On-board diagnosis
Type of diagnosis:
Enable criteria:
| Battery voltage must be between 11 - 16 V. |
| Engine running (with at least 7700 combustions). |
| Preheating active for more than 4 s. |
| Lambda control active for more then 5 s. |
| Fuel shut-off for more than 7 s. |
Fault criteria:
| When voltage across sensor has not been below 400mV after a 7 second fuel shut-off. |
Dependent:
System reaction to a fault:
| Preheating is switched off. |
| Adaption of rear oxygen sensor is blocked and reset. |
OK report:
| Diagnosis completed without fault report. |
Fault handling:
| (See section Fault handling III, "Other emission-related components and functions" for more information.) |
Checking the wiring harness
Move the wiring harness at several spots and in several directions to reveal intermittent breaks and short-circuits. Check switches, connectors and crimp connections for oxidation, retracted pins and pin clamping force.
Diagnostic help
Diagnosis regards:
| Electrical fault in connecting leads or component. |
| The voltage across a defective sensor is 0.40V - 0.50V. OK if it exceeds 0.55V. |
Functions in the diagnostic tool related to the fault:
| (See also description of readings/activations in diagnostic tool) |
