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Home >> Pontiac >> 2002 >> Aztek AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics >> Diagnostic Tests >> DTC P0719: Brake Switch Circuit - Low Input >> Diagnostic Procedure
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Diagnostic Procedure

  1. Did you perform the Diagnostic System Check-Engine Controls? If yes, go to next step. If no, see DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
    2. NOTE: Before clearing the DTC, use the scan tool in order to record the Failure Records. Using the Clear Info function erases the Failure Records from the PCM.
  2. Install a scan tool. Turn ON the ignition, with the engine OFF. Record the Failure Records. Clear the DTCs. With the scan tool, observe the TCC Brake Switch parameter. Does the scan tool display Closed? If yes, see INTERMITTENT CONDITIONS  under SELF-DIAGNOSTIC SYSTEM. If no, go to next step.
    3. NOTE: The condition that affects this circuit may exist in other connecting branches of the circuit.
  3. Remove the fuse from the ignition 1 voltage circuit of the TCC brake switch. Inspect the fuse for an open. Replace the fuse if necessary. Was the fuse open? If yes, go to next step. If no, go to step  5.
    4. NOTE: The condition that affects this circuit may exist in other connecting branches of the circuit.
  4. Test the ignition 1 voltage circuit (CKT 1239) of the TCC brake switch for a short to ground between the fuse block and the brake switch. Test the signal circuit (CKT 420) of the TCC brake switch for a short to ground between the PCM and the TCC brake switch. Repair as necessary. After repairs, go to step  10.
    5. CAUTION: When you are performing service on or near the SIR components or the SIR wiring, you must disable the SIR system. See appropriate AIR BAG RESTRAINT SYSTEMS article in ACCESSORIES & EQUIPMENT. Failure to follow the correct procedure could cause air bag deployment, personal injury, or unnecessary SIR system repairs.
  5. Disconnect TCC brake switch 4-way connector. Connect a fused jumper wire from terminal C to terminal D of the TCC brake switch connector. Turn ON the ignition with the engine OFF. With a scan tool, observe the TCC Brake Switch status. Does the scan tool display change to Closed? If yes, go to step  8. If no, go to next step.
  6. Test the ignition 1 voltage circuit (CKT 1239) of the TCC brake switch for an open between the fuse block and the brake switch. Did you find and correct the condition? If yes, go to step  10. If no, go to next step.
  7. Test the signal circuit (CKT 420) of the TCC brake switch for an open between the PCM and the brake switch. Did you find and correct the condition? If yes, go to step  10. If no, go to step  9.
  8. Replace the TCC brake switch. After repairs, go to step  10.
  9. Replace the PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Reprogram PCM. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After repairs, go to next step.
  10. Perform the following procedure in order to verify the repair:
    • Select DTC.
    • Select Clear Info.
    • Turn ON the ignition with the engine OFF. The TCC brake switch must be Closed, pedal released, for more than 2 seconds.
    • Select Specific DTC.
    • Enter DTC P0719.

    Has the test run and passed? If yes, system is okay. If no, go to step  1.

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