P114C

277D - P114C

Information saved in
DME

Fault code
277D - P114C

Fault text
Oxygen sensor trim control diagnosis, Bank 2

Fault description


Condition for fault identification
Test condition:
Active trim control (steady-state operation between 2000
and 3000 rpm in part-load range....min. 120 sec.) and active
P-component
Terminal condition: Engine running
Voltage condition:
none

Condition for fault memory entry
Suspicion of lean mixture based on P-component
(K_LA_TRIM_P_ANZ_Max +
K_LA_TRIM_DIAG_P_SCHW P jumps) leads to targeted
rich/lean control intervention;
if the pre-cat and post-catalyst oxygen sensors respond as
expected, then a trimming error is recognized.

Action in service
1) Check induction system and exhaust system for leaks;
incl. operation of the HFM/ ...if no defect is present. 2.)
Carry out oxygen sensor test routine. 3.) If the system test
fails to produce a result and the trim control error is still
present -> Replace the pre-catalyst oxygen sensor.

Fault effect and breakdown warning
MIL on after engine runs 2x / no effects on drivability

Driver information
Warning light:
No

Service instruction
none