B1344

Schematic:

CIRCUIT DESCRIPTION
The rear junction block supplies ignition voltage through circuit 141 (BRN). The Instrument Panel Module (IPM) commands the actuator to move by supplying voltage on the command circuit 1318 (YEL). The command line voltage and motor actions are as follows:
^ 0 volts moves toward defrost.
^ 2.5 volts stops the motor.
^ 5 volts moves toward A/C.

The IPM determines the current position by monitoring the voltage on the feedback circuit 1814 (YEL/BLK). A feedback potentiometer supplies a regulated 5 volt signal by the IPM on circuit 705 (GRY), and a ground from the IPM circuit 1791 (YEL). The pot is gear driven inside the actuator. The feedback voltage is a function of the motor position with a high voltage of 4-5 volts indicating A/C door position. A low voltage of less then 1 volt indicates the defrost position. Operation of the air mix door actuator can be evaluated through Scan Tool data.

CONDITIONS FOR SETTING THE DTC
^ Ignition is ON.
^ Feedback circuit is open or shorted.

ACTION TAKEN WHEN THE DTC SETS
^ A default value of 128 counts will be used by the IPM.
^ This default value results in only two positions of the actuator A/C and Defrost being used by the system.

CONDITIONS FOR CLEARING THE MIL/DTC
^ Using a Scan Tool.
^ A current DTC will clear when the diagnostic runs and does not fail.
^ IPM battery voltage is interrupted.

TEST DESCRIPTION

Steps 1-12:

Steps 13-21:

The numbers below refer to the step numbers on the diagnostic table.
1. Perform the Body Control Module Diagnostic (BCM) Diagnostic System Check before continuing with the diagnosis of this DTC. Initial Inspection and Diagnostic Overview
2. This test allows the Scan Tool to recalibrate the actuator.
11. Determines if the Instrument Panel Integration Module (IPM) is malfunctioning.
14. Determines if the actuator is operational.