Fuel Trim Monitor
This monitor applies to DTCs P0171, P0172, P0174 and P0175. Following conditions must be met during the test:
- Engine coolant temperature is 176-207°F (80-97°C).
- Atmospheric temperature is 14-140°F (-10-60°C).
- Selector lever is in "D" range.
Monitor takes about 35 minutes to complete. This cycle must be completed 2 times. Run monitor as shown. See Fig 1 . Remove all test equipment from vehicle and install all components and connectors that were removed or disconnected during testing. Perform steps as follows:
- Start engine and accelerate to 55-60 MPH.
- Drive at 55-60 MPH for 30 minutes or more. During this period DO NOT drive at constant speed for more than 120 seconds. Carry out gradual deceleration and acceleration within every 120 second time frame.
- Return vehicle to shop and Turn the ignition switch to LOCK position. Recheck for DTCs. If DTC P0171, P0172, P0174 or P0175 resets, return to appropriate repair procedure under DIAGNOSTIC TESTS .