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Home >> Saturn >> 1999 >> SL1 Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Basic Engine Testing >> Engine Controls Circuit Checks >> Power Relay Circuit (CATERA)
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Power Relay Circuit (CATERA)

  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. Inspect fuse V5 (80-amp), located in power distribution fuse block. If fuse is open, go to step  7 . If fuse is okay, go to next step.
  3. Turn ignition off. Remove engine controls power relay from ECM housing. Using a fused jumper wire, jumper battery feed circuit and switched B+ circuit together at engine controls power relay connector. See appropriate wiring diagram in WIRING DIAGRAMS article. Attempt to start engine. If engine starts, go to step  8 . If engine does not start, go to next step.
  4. Using a test light connected to ground, probe both battery feed circuits at engine controls power relay connector. See appropriate wiring diagram in WIRING DIAGRAMS article. If test light illuminates at both circuits, go to next step. If test light does not illuminate at both circuits, go to step  7 .
  5. Turn ignition off. Using a test light connected to battery positive, probe engine controls power relay control circuit and switched B+ circuit at engine controls power relay connector. See appropriate wiring diagram in WIRING DIAGRAMS article. Turn ignition on. If test light illuminates at both circuits, go to step  7 . If test light does not illuminate at both circuits, go to next step.
  6. Turn ignition off. Disconnect ECM harness connectors. Using DVOM, check for continuity in engine controls power relay control circuit between engine controls power relay connector and ECM harness connector. See appropriate wiring diagram in WIRING DIAGRAMS article. If continuity is present, go to step  12 . If continuity is not present, go to step  9 .
  7. Repair battery feed circuit.
  8. Replace engine controls power relay.
  9. Repair open or high resistance in engine controls power relay control circuit.
  10. Check for poor ECM harness connections. After repairs, go to step  12 . If connections are okay, go to next step.
  11. Replace ECM. Perform ECM relearn procedures. After repairs, go to next step.
  12. Using scan tool, clear Diagnostic Trouble Codes (DTCs). Attempt to start engine. If engine starts and continues to run, go to next step. If engine does not start, or starts and then stalls, go to step  2 .
  13. Allow engine to idle until normal operating temperature is reached. Using scan tool, check for DTCs. If any DTCs are present, perform appropriate DTC test. See appropriate SELF-DIAGNOSTICS article. If no DTCs are present, go to next step.
  14. If any additional DTCs were noted during On-Board Diagnostic (OBD) system check that have not been diagnosed, perform appropriate DTC test. See appropriate SELF-DIAGNOSTICS article. If no additional DTCs were noted, system is okay.
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