118401 - P0171 (DME)

118401 - P0171

Information saved in
DME

Fault code
118401 - P0171

Fault text
Mixture control: mixture too lean; large deviation

Fault description
The diagnostic function monitors the lambda closed-loop
mixture control.

Condition for fault identification
Test condition:
The fault is recognized when the mixture for Bank 1 is too
lean and the adaptation limit (30 %) is exceeded for 50 sec.
Potential problem source(s):
Defective intake-manifold pressure sensor before and behind
throttle valve
- Leak in exhaust system
- Catalytic converter clogged
- Fuel injector defective
Terminal condition: none
Voltage condition:
- Electrical system voltage > 10 V
Temperature condition:
- Ambient temperature > -10 °C
Time condition:
- None
Other conditions:
- Engine on

Condition for fault memory entry
The diagnostic fault code is logged when specified
conditions are satisfied, but a reaction period cannot be
provided.

Action in service
- Visual inspection of affected components
- Locate and repair leaks
- Replace pressure sensors in induction tract
- Check plugs and electrical wires to pressure sensors in
induction tract
- Melted catalyst on one bank (visual inspection through
sensor fittings)

Fault effect and breakdown warning
Breakdown notice:
- none
Possible apparent symptoms:
- Engine running
- Bad (miss,
- poor idle quality)

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