FixVault
Home › Oldsmobile › 1992 › Cutlass Supreme Base › Repair and Diagnosis › Heating, Ventilation & A/C (HVAC) › HVAC Control Systems › A/C-Heater System - Automatic › Self-Diagnostics › Code 09, Serial Data Line Test

Code 09, Serial Data Line Test

  1. With ignition switch in OFF position, disconnect A/C-heater control unit connector C3 (Black connector). Turn ignition switch to RUN position. Using a voltmeter, check if approximately 5 volts exist between terminal No. 9 (Orange wire) and ground at A/C-heater control unit connector C3.
  2. If voltmeter does not indicate 5 volts, check Orange wire for an open. If voltmeter indicates 5 volts, proceed to A/C-HEATER CONTROL UNIT VOLTAGE TEST under TESTING.
About FixVault