(DME) Condition For Fault ID - 2

277C - P114B

Information saved in
DME

Fault code
277C - P114B

Fault text
Oxygen sensor trim control diagnosis, bank 1

Fault description
Post Catalyst Fuel Trim Via Oxygen Sensor System Too
Lean (Bank 1)

Condition for fault identification
Test condition:
LEAN suspected under consideration of P-component ((6
(K_LA_TRIM_P_ANZ_MAX) + 3
(K_LA_TRIM_DIAG_P_SCHW P-spikes)) leads to
deliberate RICH/LEAN control activation;
if the pre-catalyst and post-catalyst oxygen sensors respond
accordingly a trim control error is recognized.
Terminal condition: Engine running
Voltage condition:
none

Condition for fault memory entry
none

Action in service
1) Check intake and exhaust systems for leaks; incl. HFM
operation/ ..if no fault is present.. 2.) Conduct oxygen sensor
test routine/ 3.) If the test does not produce any results and
the trim control error is still present ->Replace the sensor
before the catalytic converter

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

Driver information
Warning light:
MIL

Service instruction
none