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Home >> Chevrolet >> 1997 >> Venture LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Tests W/Codes >> Diagnostic Trouble Codes >> DTC P1663 - Generator Light Control Circuit >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING article. After performing OBD system check, go to next step.
  2. Check instrument cluster system. After diagnosing instrument cluster, go to next step.
  3. Turn ignition off. Disconnect PCM harness connector. Using DVOM, check voltage between affected PCM output circuit at PCM harness connector and ground. If voltage reading is near battery voltage, go to next step. If not, go to step 7).
  4. Set DVOM to 10-amp scale. Check current between affected PCM output circuit and ground. Monitor reading for at least 2 minutes. If current reads between 0.05-1.50 amps, go to step 12). If not, go to next step.
  5. Disconnect instrument panel cluster connector. Using DVOM, check voltage between affected PCM output circuit and ground. If voltage reading is zero volts, go to step 15). If voltage reading is not zero volts, go to next step.
  6. Locate and repair short to voltage in affected PCM output circuit. After repairs, go to step 3).
  7. Remove and inspect fuse for generator light control circuit. If fuse is blown, go to next step. If fuse is okay, go to step 9).
  8. Locate and repair short to ground in ignition feed circuit for instrument cluster indicator lights. Replace fuse. After repairs, go to step 3).
  9. Disconnect instrument cluster connector. Turn ignition on. Check voltage between ground and ignition feed circuit terminal at instrument panel cluster connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 14).
  10. Check for an open or short to ground in generator light control circuit. Repair as necessary. After repairs, go to step 3). If circuit is okay, go to next step.
  11. Check generator light control circuit and ignition feed circuit for poor terminal connection at instrument panel cluster connector and at PCM connector. Repair as necessary. After repairs, go to step 3). If connections are okay, go to step 15).
  12. Turn ignition off. Reconnect PCM connector. Disconnect instrument panel cluster connector. Turn ignition on. Connect a test light between generator light control circuit and ignition feed circuit terminals at instrument cluster connector. Using scan tool, select OUTPUTS TEST function and cycle generator light on and off. If test light flashes, see DIAGNOSTIC AIDS. If test light does not flash, go to next step.
  13. Check generator light control circuit for poor terminal connection at PCM. Repair as necessary. After repairs, go to step 3). If connection is okay, go to step 16).
  14. Locate and repair open in ignition feed circuit to instrument cluster indicator lights. After repairs, go to step 3).
  15. Replace instrument cluster. After repair is completed, go to step 3).
  16. Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
  17. Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME data and note parameters. Start engine and operate vehicle within conditions required for setting this DTC, and as close to conditions recorded in FREEZE FRAME as possible. Monitor SPECIFIC DTC info for DTC P1655 until DTC P1655 test runs. If scan tool indicates FAILED THIS IGN, repeat step 2). If scan tool does not indicate FAILED THIS IGN, repair is complete.
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