B1002–A/C SWITCH REQUEST INPUT CIRCUIT HIGH (CCN)For a complete wiring diagram Refer to Section 8W.When Monitored:With the ignition on.Set Condition:If the Instrument Cluster (CCN) detects voltage above 4.5 volts for 10 seconds on the (C105) HVAC MUX Control circuit.
Possible Causes(C105) HVAC MUX CONTROL CIRCUIT SHORTED TO VOLTAGE(C105) HVAC MUX CONTROL CIRCUIT OPEN(C955) HVAC MUX RETURN CIRCUIT OPENA/C HEATER CONTROLINSTRUMENT CLUSTER (CCN)
Diagnostic Test1.VERIFY DTC B1002–A/C SWITCH REQUEST INPUT CIRCUIT HIGH IS ACTIVETurn the ignition on.With the scan tool, erase DTCs.Turn the ignition off, wait 10 seconds, and turn the ignition on.With the scan tool, read DTCs.Does the scan tool display this DTC as active?YesGo To 2NoCheck for an intermittent condition by inspecting the related wiring harness for chafed, pierced, pinched, and partially broken wires. Also, inspect the related
connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals. Repair as necessary.Perform the BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).2.CHECK THE (C105) HVAC MUX CONTROL CIRCUIT FOR A SHORT TO VOLTAGETurn the ignition off.Disconnect the Instrument Cluster C2 harness connector.Disconnect the HVAC Control Head C1 harness connector.Turn the ignition on.Measure the voltage of the (C105) HVAC MUX Control circuit.Is there any voltage present?YesRepair the (C105) HVAC MUX Control circuit for a short to voltage.Perform the BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).NoGo To33.CHECK THE (C105) HVAC MUX CONTROL CIRCUIT FOR AN OPENTurn the ignition off.Measure the resistance of the (C105) HVAC MUX Control circuit between the A/C Heater Control C1 harness connector and the Instrument Cluster C2 harness connector.Does the ohm meter read open circuit?YesRepair the (C105) HVAC MUX Control circuit for an open.Perform the BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).NoGo To54.CHECK THE (C955) HVAC MUX RETURN CIRCUIT FOR AN OPENMeasure the resistance of the (C955) HVAC MUX Return circuit between the A/C Heater Control C1 harness connector and the Instrument Cluster C2 harness connector.Does the ohm meter read open circuit?YesRepair the (C955) HVAC MUX Return circuit for an open.Perform the BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).NoGo To55.CHECK THE OPERATION OF THE INSTRUMENT CLUSTER (CCN)Reconnect the Instrument Cluster (CCN) harness connector.Turn the ignition on.With the scan tool, read DTCs.Does the scan tool display this DTC as active?YesReplace the Instrument Cluster (CCN) in accordance with the service information.Perform the BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).NoReplace the HVAC control head in accordance with the service information.Perform the BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).