LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 1998 >> Envoy >> Repair and Diagnosis >> Body & Frame >> Door Locks >> Anti-Theft System >> System Tests >> System Test

System Test

  1. Ensure system check has been performed. See SYSTEM CHECK  . After performing system check, go to next step.
  2. Connect scan tool. Turn ignition on. Using scan tool, check Ignition 1 input. Ignition 1 should be ACTIVE. Check passlock state. Passlock state should be Normal Decision. Check battery, fuses and power to TBC module (Ignition 1 and power). Repair as necessary. If repair was needed, go to step 14). If no repair was needed, go to next step.
  3. Using scan tool, check battery voltage. If voltage reading is more than 8 volts, go to next step. If voltage reading is 8 volts or less, repair power supply as necessary.
  4. Turn ignition switch to START position. If engine cranks fast enough to start, go to step 6). If engine does not crank fast enough to start, go to next step.
  5. Check starting system. See STARTER article in ELECTRICAL.
  6. Check resistance between ground and TBC module connector C1 terminals A1 and B1. If resistance is more than 25 ohms, go to next step. If resistance is 25 ohms or less, go to step 8).
  7. Repair ground circuits. After repairs, go to step 13).
  8. Using scan tool, check for communication to TBC. If communication does not exist, go to next step. If communication exists, go to step 10).
  9. Repair Class 2 serial data line communications. See WIRING DIAGRAMS  . Go to step 13).
  10. Check for current DTCs. If no DTCs exist, go to next step. If any DTCs exist, go to applicable test under DIAGNOSTIC TESTS  . 11) Using scan tool, verify PCM/VCM is receiving password from TBC. If PCM/VCM is receiving password, see appropriate TESTS W/CODES article in ENGINE PERFORMANCE section:

    If PCM/VCM is not receiving password, go to next step.

  11. Reprogram TBC. Perform learn procedure. See PROGRAMMING  . Verify PCM/VCM is receiving password from TBC. Turn ignition switch to START position. If engine starts, go to step 13). If engine does not start, go to next step.
  12. Replace TBC. Reprogram TBC. Perform learn procedure. See PROGRAMMING  . Go to next step.
  13. Clear DTCs. Perform system check. See SYSTEM CHECK  .
scientia non olet · About LEMON Manuals