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Home >> Saturn >> 2000 >> SC2 Automatic, MP6 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0418: Secondary Air Injection System Relay Circuit >> Diagnostic Procedures
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Diagnostic Procedures

  1. Turn ignition on, with engine off. Using scan tool, monitor AIR PUMP REL. - LOW VOLT or AIR PUMP REL. - OPEN test. If scan tool does not indicate TEST FAIL, see DIAGNOSTIC AIDS  . If scan tool indicates TEST FAIL, go to next step.
  2. Remove air pump relay from underhood fuse/relay block. Install a known-good air pump relay. Using scan tool, monitor AIR PUMP REL. - LOW VOLT or AIR PUMP REL. - OPEN test. If scan tool indicates TEST PASS, repair terminal tightness at relay connector. If scan tool does not indicate TEST PASS, go to next step.
  3. Verify if air pump relay clicks. If relay clicks, repair Brown wire between relay and PCM for short to ground or PCM. If relay does not click, check for open in Brown wire between relay and PCM or for terminal tightness. Repair as necessary. If circuit or terminal connector is okay, replace PCM.
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