P0036

12B304 - P0036

Information saved in
DME

Fault code
12B304 - P0036

Fault text
Oxygen-sensor heater after catalytic converter, activation:
open circuit

Fault description
The diagnostic function monitors activation of the heater for
the oxygen sensor behind the catalytic converter.

Condition for fault identification
Test condition:
The fault is recognized when an activation signal is
transmitted to the heater for the oxygen sensor behind the
catalytic converter and an electrical defect is present.
Potential problem source(s):
- Defective wiring harness
- Oxygen sensor behind catalytic converter defective
- Defective DME
Terminal condition: none
Voltage condition:
- Onboard electrical system voltage between 9 V and 16 V
Temperature condition:
- None
Time condition:
- 10 sec. after engine start
Other conditions:
- Engine ON

Condition for fault memory entry
This fault is logged in the control module's fault memory
immediately.

Action in service
- Inspect wiring harness between oxygen sensor behind
catalytic converter and DME
- Replace oxygen sensor behind catalytic converter
- Replace DME

Fault effect and breakdown warning
Breakdown notice:
Continued driving is possible, but because the oxygen
sensor is not ready for closed-loop control, conversion of
exhaust gases in the catalytic converter will be seriously
impaired.
Possible apparent symptoms:
- MIL lamp lights up after 2nd driving cycle

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
None