Hi CarLover,
Circuit Description
Fuel trim refers to feedback compensation value compared against basic injection time. Fuel trim includes short-term and long-term fuel trim.
DTC P0171 is set when fuel trim is driven rich beyond a certain value.
Possible causes are: ï¬
Air induction system malfunction. ï¬
Fuel injector restricted. ï¬
Defective Mass Airflow (MAF) meter. ï¬
Defective Engine Coolant Temperature (ECT) sensor.
Improper fuel pressure. ï¬
Exhaust system leak. ï¬
Air/Fuel (A/F) sensor circuit is open or shorted. ï¬
Defective Air/Fuel (A/F) sensor. ï¬
Vehicle is ran out of fuel. ï¬
Defective ECM.
© 2007 Mitchell Repair Information Co., LLC.
SELF-DIAGNOSTICS -2000 Toyota Corolla LE 9/28/2008
http://www.ondemand5.com/mric/common/asp/printart.aspx
Sep 27, 2008 at 12:06 PM