Circuit Description
WARNING: This page is about a different car, the 2002 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
Fuel trim refers to feedback compensation value compared against basic injection time. Fuel trim includes short-term and long-term fuel trim.
DTC P0174 is set when fuel trim is driven rich beyond a certain value with engine at normal operating temperature and the actual air/fuel ratio is lean. Possible causes are:
- Air induction system malfunction.
- Fuel injector restricted.
- Defective Mass Airflow (MAF) meter.
- Defective Engine Coolant Temperature (ECT) sensor.
- Ignition system malfunction.
- Improper fuel pressure.
- Exhaust system leak.
- Heated oxygen sensor (bank No. 2 sensor No. 1) circuit is open or shorted.
- Defective heated oxygen sensor (bank No. 2 sensor No. 1).
- Defective ECM.
- Vehicle ran out of fuel.
- Defective Positive Crankcase Ventilation (PCV) valve piping.
DTC P0175 is set when fuel trim is driven lean beyond a certain value with engine at normal operating temperature and the actual air/fuel ratio is rich. Possible causes are:
- Air induction system malfunction.
- Fuel injector restricted or leaking.
- Defective Mass Airflow (MAF) meter.
- Defective Engine Coolant Temperature (ECT) sensor.
- Ignition system malfunction.
- Improper fuel pressure.
- Exhaust system leak.
- Heated oxygen sensor (bank No. 2 sensor No. 1) circuit is open or shorted.
- Defective heated oxygen sensor (bank No. 2 sensor No. 1).
- Defective ECM.
- Vehicle ran out of fuel.
- Defective Positive Crankcase Ventilation (PCV) valve piping.