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HOMESERVICE MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 89 (ENGINE CONTROL SYSTEM SELF-DIAGNOSTICS - 3.1L ENGINE)DIAGNOSTIC TESTSDTC P0401: EGR SYSTEMCONDITIONS FOR RUNNING DTC
2003 Chevrolet TrailBlazer 4.2 S, 4WD

Conditions For Running DTC

2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Conditions For Running DTC
WARNING: This page is about a different car, the 2002 Pontiac Grand Prix, 2002 Chevrolet Malibu, and 2002 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
  • DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0201-P0206, P0300, P0336, P0403, P0404, P0405, P0502, P0503, P0506, P0507, P1106, P1107, P1111, P1112, P1114, P1115, P1121, P1122, P1374, or P1404 are not set.
  • The system voltage is 10-18 volts.
  • The AC status does not change.
  • The transaxle range does not change.
  • The Throttle Position (TP) angle is less than 1 percent, deceleration.
  • The Intake Air Temperature (IAT) is more than 176°F (80°C).
  • The Engine Coolant Temperature (ECT) is more than 167°F (75°C).
  • The engine speed is 1050-1300 RPM.
  • The Idle Air Control (IAC) position is steady.
  • The MAP is steady at 15-70 kPa.
  • The vehicle speed is more than 35 MPH during deceleration.
  • The Barometric Pressure (BARO) sensor less than 70 kPa.
  • The vehicle will need to be driven at greater than 50 MPH, and then allowed to decelerate. When the vehicle is decelerating while meeting all of the criteria listed above, the PCM will enable the test to run. When the test is running, you will see the desired EGR parameter and the EGR position sensor on the scan tool change from 0 to a calibrated value greater than 0.
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