12B701

12B701 - P0141

Information saved in
DME

Fault code
12B701 - P0141

Fault text
Oxygen-sensor heater after catalytic converter, function:
internal resistance too high

Fault description
The diagnostic function monitors the difference between the
expected and the actual internal resistance in the heater for
the oxygen sensor behind the catalytic converter.

Condition for fault identification
Test condition:
The fault is recognized when the actual internal resistance of
the heater for the oxygen sensor behind the catalytic
converter remains higher than expected for a specified
period of time.
Potential problem source(s):
- Defective wiring harness
- Oxygen sensor behind catalytic converter defective
Terminal condition: none
Voltage condition:
- Onboard electrical system voltage between 9 V and 16 V
Temperature condition:
- None
Time condition:
- Engine off for longer than 13 min.
Other conditions:
- Engine ON

Condition for fault memory entry
The diagnostic fault code is logged when the fault remains
present for longer than 1 min.

Action in service
- Check wiring harness between oxygen sensor behind
catalytic converter and DME (contact resistance)
- Replace oxygen sensor behind catalytic converter

Fault effect and breakdown warning
Breakdown notice:
None
Possible apparent symptoms:
None

Driver information
Warning light:
- ECE emissions warning lamp: on
- ECE electronic engine power reduction: on
- CC message: on
- US emissions warning lamp: off
- US electronic engine power reduction: off
- CC message: none

Service instruction
Because diagnosis relies on assessment of the post-catalyst
oxygen sensor,
following logging of a diagnostic fault code the exhaust
system must be inspected for leaks
and sealed if any leakage is found (without additional repair)