Fuel Trim Monitor
This monitor applies to DTCs P0171, P0172, P0174 and P0175. Following conditions must be met during test:
- Engine coolant temperature is 176-203°F (80-95°C).
- Ambient temperature is 14°F (-10°C) or more.
- Selector lever is in "D" range.
This one trip monitor, takes about 35 minutes to complete. Remove all test equipment from vehicle and install all components and connectors that were removed or disconnected during testing. To run monitor, use illustration and perform following steps. See Fig 1. Step numbers in procedure will correspond to step numbers in illustration.
- After engine coolant temperature is at 176-203°F (80-95°C), turn off ignition.
- Start engine and quickly accelerate to 55-60 MPH.
- Drive at 55-60 MPH for 30 seconds or more. Carry out gradual deceleration and acceleration within the previously stated vehicle speed for another 2 minutes. You are allowed to brake during this period but avoid sudden acceleration or deceleration.
- Stop vehicle and turn ignition off.