P0171

P0171 00

Long Term Fuel Trim Multiplicative. Max Value, Air/Fuel too Lean.







Fault symptom
- Check Engine (OBDII, EOBD).
- The engine may stop after starting, run unevenly and misfire.

On-board diagnosis

Type of diagnosis:
- Continuous

Enable criteria:
- The engine has started and lambda control is active.
- A multiplicative adaptation is carried out.

- NONE of the following DTCs must be detected:
- P0444, P0445

Fault criteria:
- Multiplicative adaptation has bottomed at +25%.

Dependent:
P0101, P0102, P0103
P0131, P0132, P0134
P0117, P0118

System reaction to a fault:
- None

OK report:
- Provided that the fault criteria are not fulfilled during the operating cycle, there is an OK report upon ignition shut-off before the engine stops. Two types of OK reports are possible:
Type 1: If there is already a DTC stored for the diagnosis and operating conditions were the same (coolant temperature over or under 71 degree C, engine speed 375 rpm and load 10%).
Type 2: If there is no DTC stored for the diagnosis or if operating conditions were not the same.

Fault handling:
Type II
(See section Fault handling II, "Emission-related misfiring or fault in fuel system" for more information.)

Diagnostic help

Diagnosis regards:
Checking air/fuel ratio. With this DTC, the engine will be getting too much air or too little fuel.

Functions in the diagnostic tool related to the fault:

Test value:
- O2S 1
- Multiplicative Adaptation
- Short Term Fuel Trim
- Purge Adaptation
- Airmass Deviation from Calculated
(See also description of readings/activations in diagnostic tool)