Conditions for Running the DTC

P0401

• 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 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 intake air temperature (IAT) sensor is between -3 and +120°C (+27 and +248°F).
  • The barometric pressure (BARO) is greater than 82 kPa.
  • The vehicle speed is greater than 30 km/h (19 mph) before deceleration.
  • The throttle position is less than 1.5 percent.
• The EGR flow test is ran when the following conditions are met during DFCO mode:
  • The EGR position is less than 1 percent.
  • The MAP is between 11-55 kPa.
  • The engine speed is between 1,600-3,200 RPM.
  • The MAP does not vary greater than 3 kPa.
• The EGR flow test is performed once per ignition cycle.
• The DTC runs multiple times on the first ignition cycle after the DTC is cleared from the ECM memory.

P0402

• The engine is cranking.
• The ignition voltage is between 10-16 volts.
• The DTC runs continuously when the above conditions are met.