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Home >> Chevrolet >> 1999 >> Metro Base, 2D Hatchback >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Basic Testing >> No Start Diagnosis >> No Start-Engine Cranks Okay (1.3L) >> Main Relay Circuit

Main Relay Circuit

  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article. After performing OBD system check, go to next step.
  2. Check for open IG-COIL fuse (15-amp) located in junction block, or open FI fuse (15-amp) located in fuse box. If either fuse is open, go to step  13. If fuses are okay, go to next step.
  3. Turn ignition on with engine off. Remove and reinstall main relay several times while listening for a "clicking" sound from relay. If a "clicking" sound is heard, go to DIAGNOSTIC AIDS . If relay does not click, go to next step.
  4. Turn ignition off. Remove main relay. Turn ignition on with engine off. Using a test light connected to ground, probe battery feed circuit (cavity No. 4) at main relay connector. See appropriate wiring diagram in WIRING DIAGRAMS article. If test light illuminates, go to next step. If test light does not illuminate, go to step  7.
  5. Using a test light connected to ground, probe battery feed circuit (cavity No. 1) at main relay connector. See appropriate wiring diagram in WIRING DIAGRAMS article. If test light illuminates, go to next step. If test light does not illuminate, go to step  7.
  6. Turn ignition off. Using a test light connected to battery positive, probe main relay control (cavity No. 2) at main relay connector. See appropriate wiring diagram in WIRING DIAGRAMS article. If test light illuminates, go to step  14. If test light does not illuminate, go to step  8.
  7. Repair open in battery positive feed circuit between FI fuse and main relay. After repairs, go to step  16.
  8. Check for an open in main relay control circuit between main relay and PCM. Repair as necessary. After repairs, go to step  16. If circuit is okay, go to next step.
  9. Using a test light connected to ground, backprobe ignition positive voltage circuit at PCM harness connector C3. See appropriate wiring diagram in WIRING DIAGRAMS article. If test light illuminates, go to step  11. If test light does not illuminate, go to next step.
  10. Repair open in ignition positive voltage circuit between IG-COIL fuse and PCM. After repairs, go to step  16.
  11. Disconnect PCM harness connector C1. Using a test light connected to battery positive, probe terminals No. 1, 13 and 26 (ground circuits). See appropriate wiring diagram in WIRING DIAGRAMS article. If test light illuminates at each terminal, go to step  15. If test light does not illuminate at each terminal, go to next step.
  12. Repair open in appropriate ground circuit. After repairs, go to step  16.
  13. Repair short to ground in IG-COIL fuse circuit or FI fuse circuit. After repairs, go to step  16.
  14. Replace main relay. After repairs, go to step  16.
  15. Replace PCM. After repairs, go to next step.
  16. Operate vehicle under conditions in which problem originally occurred. If problem no longer exists, and no DTCs are present, system is okay. If DTCs are present, go to appropriate DTC test. See appropriate SELF-DIAGNOSTICS article.
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