Fault Conditions

P1181

Long Term Fuel Trim Additive. Max Value, Air/Fuel Too Lean.







Fault symptoms
- CHECK ENGINE.
- The engine may stop after starting, run unevenly and misfire, or idle speed too fast.

On-Board Diagnostics

Type of diagnosis:
- Continuous. But interrupted when fault criteria fulfilled and will not restart until next driving cycle.

Enable criteria:
- Engine running and closed loop active. One multiplicative and one additive adaptation performed.

Fault criteria:
- Additive adaptation exceeds 3.33 mg/c for more than 30s.

Dependents:
- P0115, P0116, P0117, P0118, P0119, P0131, P0132, P0134, P0444, P0445 and P1133.

System reaction to a fault:
- None.

OK report:
- On condition that the fault criteria are not fulfilled during the driving cycle the OK report occurs at ignition off before the engine stalls. Two types of OK reports can be given: Type 1: If a DTC is already stored for the diagnosis and similar operating conditions have occurred (coolant temperature above or below 71 degree C, engine speed 375 rpm and load 10%). Type 2: If there is no DTC stored for the diagnosis or similar operating conditions have not occurred

Fault Handling: (For more information refer to "Fault diagnosis, general". Fault Handling II, Emission-Related Misfiring or Fault In Fuel System)

- Type II.

Diagnostic help
When idling the need of fuel to the engine has been 3.33 mg/c greater than that which the control module had calculated with the information received from the mass air flow sensor

Fault diagnosis first determines whether the pressure sensors show about the same value with the ignition ON, as the mass air flow sensor is later compared with the intake air pressure. If the pressure sensors are OK but the mass air flow sensor is incorrect then check for air leaks after the throttle and thereafter, change the mass air flow sensor.

If the air quantity is OK, then the fuel supply is checked, i.e. pressure, response, pump flow and finally the injectors.

Functions in the diagnostic tool related to the fault:
- Diagnostic status for the diagnosis.
- O2S 1, unit V
- Additive adaptation, unit mg/c.
- Closed loop, unit %.
- Purge Adaptation, unit %.
- Air mass deviation from calculated, unit %.

For more information refer to description of test values under "Fault diagnosis, general". Menu Read Values