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Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 248 (Engine Control System & Fuel - Hybrid (Hp2) 6.0L (LFA) - DTC P0010 To DTC P0230) >> DTC P0102 or P0103 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2008 GMC Yukon and 2008 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT: All electrical components and accessories must be turned OFF and allowed to power down.
  1. Ignition OFF, open the hood to disable the Auto-Stop function. Refer to Hybrid Modes of Operation Description .
  2. Ignition ON, verify the scan tool hood position parameter displays Open.
  3. Ignition OFF, disconnect the MAF/IAT harness connector at the MAF/IAT sensor.
  4. Ignition OFF for 90 seconds or until the ECM powers down, test for less than 5 ohms between the ground circuit terminal C and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  5. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal B and ground.
    • If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
  6. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal A and ground.
    • If less than the specified range, test the signal circuit terminal A for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  7. Ignition OFF, connect the red lead of the J 38522  to the signal circuit terminal A at the MAF/IAT sensor harness connector. Connect the battery voltage supply to B+, and ground the black lead.
  8. Set the J 38522  signal to 5 volts, the Frequency to 5K, and the Duty Cycle to Normal.
  9. Engine idling, observe the scan tool MAF Sensor parameter. The scan tool MAF Sensor parameter should be between 4,950-5,025 Hz.
    • If the MAF Sensor parameter is not within the specified range, replace the ECM.
  10. If all other circuits test normal, replace the MAF sensor.