27C8

27C8 - P0140

Information saved in
DME

Fault code
27C8 - P0140

Fault text
Electrical diagnosis of Bank 1 post-catalyst oxygen sensor

Fault description


Condition for fault identification
Test condition:
* Sensor heater must be active since at least
K_LSHNK_AKTIV_T * Exhaust-gas temperature >
K_LANK_DIAG_TKat * LA controller active since
K_LANK_DIAG_VK_REG_T
* Sensor temperature > K_LANK_DIAG_SONDTEMP *
Catalyst temperature > K_LANK_TKat_SCHW
Terminal condition: Engine running
Voltage condition:
ub > K_ED_PlusMin

Condition for fault memory entry
Sensor voltage
lank_us_b1 > K_LANK_USM and
lank_us_b1 < K_LANK_USF
for at least K_LANK_DIAG_OL_T

Action in service
1. Check plug and wiring harness to post-catalyst oxygen
sensor behind Bank 1 catalyst
2. If OK, replace oxygen sensor

Fault effect and breakdown warning
MIL lamp lights up after two driving cycles

Driver information
Warning light:
No

Service instruction
none