B0418

CIRCUIT DESCRIPTION
The HVAC control module 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 HVAC control module 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 HVAC control module controls the right air temperature door position in order to maintain the selected air temperature.

CONDITIONS FOR RUNNING THE DTC
^ The ignition is turned ON.
^ Ignition voltage is between 9 - 16 volts.

CONDITIONS FOR SETTING THE DTC
^ Right air temperature actuator position signal is less than 5 counts.
^ Right air temperature actuator position signal is greater than 194 counts.
^ The right air temperature actuator actual total range max-min is less than or greater than the range limits.

ACTION TAKEN WHEN THE DTC SETS
^ The HVAC control module will continue to make use of whatever right air temperature actuator travel range is still available.
^ The DTC is stored in DTC information.

CONDITIONS FOR CLEARING THE DTC
^ If the HVAC control no longer detects a failure, then the DTC will become history.
^ The history DTC will clear after 50 fault free ignition cycles.
^ The DTC can be cleared with a scan tool.

DIAGNOSTIC AIDS
^ A damaged or broken right air temperature actuator or mode door can cause this DTC to set.
^ The calibration limit is 5 - 194 counts. 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.
^ If the condition is not present, refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.

TEST

Steps 1-5:

Steps 6-15: