Conditions for Running the DTC

• DTCs P0106, P0107, P0108, P0112, P0113, P0115, P0117, P0118, P0122, P0123, P0125, P0128, P0201, P0202, P0203, P0204, P0217, P0351, P0352, P0402, P0404, P0405, P0406, P0441, P0488, P0502, P0506, and P0507 are not set.
• The EGR flow test is performed once per ignition cycle.
• DTC P0401 runs multiple times on the first ignition cycle after the DTC is cleared from the ECM memory.
• The EGR flow test is ran in decel fuel cut-off (DFCO) mode with the following conditions present before deceleration occurs:
  • The A/C compressor clutch does not change state during deceleration.
  • The ambient air temperature is more than 3°C (37°F).
  • The engine speed is between 1,550-2,900 RPM for automatic transmission or 1400-2,900 RPM for manual transmission before deceleration.
  • The manifold absolute pressure (MAP) is between 10.3-37 kPa.
  • The barometric pressure (BARO) is more than 72 kPa.
  • The vehicle speed is more than 18 km/h (11 mph) before deceleration.
• The EGR flow test is ran when the following conditions are met during DFCO mode:
  • The throttle position is less than 1 percent.
  • The EGR position is less than 1 percent.
  • The MAP does not vary more than 1 kPa.
• DTC P0401 runs continuously once the above conditions are met.

The vehicle speed needs to be more than 18 km/h (11 mph), and then allowed to decelerate. When the vehicle is decelerating, while meeting all of the criteria listed above, the ECM will enable the EGR flow test. As the EGR flow test is running, you will see the desired EGR Position parameter and the EGR Position Sensor parameter on the scan tool momentarily change from 0 to a calibrated value above 0. The EGR flow test will be disabled if one of the following conditions occur:

• The vehicle speed drops more than 4 km/h (3 mph).
• The engine speed increases more than 50 RPM during a decel.
• The actual EGR position is less than 90 percent of the commanded state.