12B501 - P3026 (DME)

12B501 - P3026

Information saved in
DME

Fault code
12B501 - P3026

Fault text
Oxygen sensor heating before catalytic converter, function:
Normal operating temperature not reached

Fault description
The diagnostic function monitors the upper and lower
temperature limits of the pre-catalyst oxygen sensor.

Condition for fault identification
Test condition:
The fault is recognized when the temperature is less than
655 °C or greater than 1000 °C and the OC diagnosis is
unable to detect an error.
Potential problem source(s):
- Defect in wiring harness to pre-catalyst oxygen sensor
- Oxygen sensor before catalytic converter defective
- Defective DME
Terminal condition: none
Voltage condition:
- None
Temperature condition:
- None
Time condition:
- Roughly 40 sec.after engine start; after approximately 15
sec. in operation
Other conditions:
- Engine on

Condition for fault memory entry
The fault is logged in the fault memory if it remains
continuously present for longer than 5 sec.

Action in service
- Defect in wiring harness to pre-catalyst oxygen sensor
- Replace pre-catalyst oxygen sensor
- Replace DME

Fault effect and breakdown warning
Breakdown notice:
- none
Possible apparent symptoms:
- none

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

Service instruction
- none