LEMON Manuals: Even more car manuals for everyone
Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 512 (Engine Controls/Fuel - 5.3L, 6.0L, 6.2L - DTC P0010 To DTC P0358) >> Diagnostic Information and Procedures >> DTC P0102 or P0103 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:

You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B75B mass air flow /intake air temperature sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 2 Ω between the ground circuit terminal B and ground.
    • If 2 Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • If less than 2 Ω 
  3. Ignition ON, verify a test lamp illuminates between the ignition voltage circuit terminal C and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF.
    2. Test for less than 2 Ω in the ignition voltage circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Ignition OFF.
    2. Test for infinite resistance between the ignition voltage circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for greater than 2 Ω between the ignition voltage circuit terminal C and ground.
      • If less than 2 Ω, repair the short to ground on the circuit.
      • If greater than 2 Ω, test all the components connected to the circuit and repair or replace as necessary.
    • If the test lamp illuminates 
  4. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal A and ground.
    • If less than 4.8 V 
    1. Ignition OFF, disconnect the X2 harness connector at the K20 engine control module.
    2. Test for infinite resistance between the signal circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K20 engine control module.
    • If greater than 5.2 V 
    1. Ignition OFF, disconnect the X2 harness connector at the K20 engine control module, ignition ON.
    2. Test for less than 1 V between the signal circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K20 engine control module.
    • If between 4.8-5.2 V 
  5. Ignition OFF, connect the red lead of the J 38522  Variable Speed Generator to the signal circuit terminal A at the harness connector. Connect the battery voltage supply to B+, and the black lead to ground.
  6. Set the J 38522  Variable Speed Generator to the following specifications.
    • Signal switch to 5 V
    • Frequency switch to 5 KHz
    • Duty Cycle switch to Normal
  7. Engine idling, observe the scan tool MAF Sensor parameter. The scan tool MAF Sensor parameter should be between 4, 950-5, 050 Hz.
    • If not between 4, 950-5, 050 Hz. 

      If not between 4, 950-5, 050 Hz., replace the K20 engine control module.

    • If between 4, 950-5, 050 Hz. 
  8. Test or replace the B75B mass air flow /intake air temperature sensor.
scientia non olet · About LEMON Manuals