LEMON Manuals: Even more car manuals for everyone
Home >> Cadillac >> 2002 >> Escalade EXT >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Fuel System (Diesel) >> Ignition (Glow Plug) Relay (6.6L) >> Diagnostic Procedure

Diagnostic Procedure

  1. Perform Diagnostic System Check - Engine Controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 6.6L SIERRA & SILVERADO article. After performing Diagnostic System Check - Engine Controls, go to next step.
  2. Turn OFF the ignition. Remove underhood electrical center cover. Remove IGN 1 relay with Relay Puller Pliers (J 43244). Probe IGN 1 relay 12-volt Switch Supply circuit at underhood electrical center terminal with test light connected to ground. Does test light illuminate? If yes, go to next step. If no, go to step  8.
  3. Turn ON the ignition, with the engine OFF. Probe IGN 1 relay 12-volt Coil Supply circuit at underhood electrical center with test light connected to ground. Does test light illuminate? If yes, go to next step. If no, go to step  9.
  4. Probe Ignition 1 Relay Control circuit at underhood electrical center with test light connected to battery voltage. Does test light illuminate? If yes, go to next step. If no, go to step  10.
  5. Turn OFF the ignition. Jumper IGN 1 Relay Switch Supply circuit and IGN 1 Relay Load circuit together using fused jumper wire. Probe ECMRPV and INJR B fuses with test light connected to ground. Does test light illuminate for both fuses? If yes, go to next step. If no, go to step  13.
  6. Inspect for poor terminal contact at IGN relay underhood electrical center connector. Did you find and correct condition? If yes, go to step  14. If no, go to next step.
  7. Replace IGN 1 relay. After repairs, go to step  14.
  8. Repair open or short to ground in 12-volt switch supply to IGN 1 relay. After repairs, go to step  14.
  9. Repair open or short to ground in 12-volt Coil Supply circuit to IGN 1 relay. After repairs, go to step  14.
  10. Test IGN 1 Relay Control circuit for an open and repair as necessary. Did you find and correct the condition? If yes, go to step  14. If no, go to next step.
  11. Test for poor or intermittent connections at ECM and repair as necessary. Did you find and correct the condition? If yes, go to step  14. If no, go to next step.
  12. Replace ECM. Perform ECM relearn procedures. See PROGRAMMING in SELF-DIAGNOSTICS - 6.6L SIERRA & SILVERADO article. After repairs, go to step  14.
  13. Replace underhood electrical center. After repairs, go to next step.
  14. Remove all test equipment except scan tool. Reconnect any disconnected components, fuses, etc. Turn ignition OFF for 30 seconds. Start engine and operate vehicle. Observe MIL, vehicle performance and driveability. Does vehicle operate normally, with no MIL illumination and no stored DTCs? If yes, system is okay. If no, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 6.6L SIERRA & SILVERADO article.
scientia non olet · About LEMON Manuals