B0279

CIRCUIT DESCRIPTION
The instrument panel integration module (IPM) commands right air temperature actuator movement with one of three voltage signals applied to the right air temperature door control circuit. A low voltage of 0 volts moves the right air temperature door toward full hot. A voltage of 2.5 volts stops the actuator. A voltage of 5 volts moves the right air temperature door toward full cold. The IPM determines the current position of the actuator by monitoring the feedback voltage of the right air temperature door position signal circuit. The feedback potentiometer position is a function of the actuator position. A high voltage indicates a full cold right air temperature door position. A low voltage indicates a full hot right air temperature door position. The IPM controls the right air temperature door position in order to maintain the selected air temperature on the HVAC control module.

Whenever the IPMs keep alive memory battery power is interrupted, the IPM will perform a recalibration of the actuators. During recalibration, the IPM will drive the actuators to their minimum and maximum travel extremes. The IPM will then calculate a travel range from this data maximum range and compare it to a calibrated range within the IPM. If the actual travel range is not within the calibrated expected range, the actuator will be considered not calibrated and the DTC will set.

CONDITIONS FOR RUNNING THE DTC
^ The ignition is turned ON.
^ The IPM power must be interrupted.
^ Perform the Recalibrate all Motors command using the scan tool.

CONDITIONS FOR SETTING THE DTC
The right air temperature actuator actual total travel range (max-mm) is less than or greater than the calibrated limits.

ACTION TAKEN WHEN THE DTC SETS
^ The IPM will continue to make use of whatever right air temperature actuator travel range is still available.
^ Each time the ignition switch is turned ON, the instrument panel integration module (IPM) will perform a recalibration of the actuator.

CONDITIONS FOR CLEARING THE DTC
^ The right air temperature actuator travel range error must be corrected.
^ The history DTC will clear after 50 fault-free ignition cycles.

DIAGNOSTIC AIDS
^ If the condition is not present, refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.
^ The range fault code can only be detected following a test of the right air temperature actuator travel range. This test can only be initiated by disrupting power to the IPM, that is, by disconnecting the battery or with the scan tool.
^ The calibration limit is 147-220 counts (2.9-4.4 V). An actual range below this limit suggests an obstruction, something stuck in the door limiting travel. An actual range above this limit suggests an over travel condition, damaged or missing foam seals.

TEST

Steps 1-2:

Steps 3-8:

Steps 9-13: