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 cold. A voltage of 2.5 volts stops the actuator. A voltage of 5 volts moves the right air temperature door toward full hot. 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 hot right air temperature door position. A low voltage indicates a full cold 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 Conditions and Poor Connections in Wiring Systems. |
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: HVAC Schematics | ||||||||||
1 | Did you review the HVAC operation and perform the necessary inspections? | -- | Go to Step 2 | |||||||
2 |
Does the left air temperature actuator drive shaft rotate for each selected position? | -- | Go to Step 3 | Go to Step 4 | ||||||
3 | Inspect the right air temperature actuator for the following:
Did you find and correct the condition? | -- | Go to Step 15 | Go to Diagnostic Aids | ||||||
4 | Test the ignition 3 voltage circuit of the right air temperature actuator for an open or a high resistance. Refer to Circuit Testing or Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 5 | ||||||
5 | Test the ground circuit of the right air temperature actuator for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 6 | ||||||
6 | Test the 5 volt reference circuit of the right air temperature actuator for an open, a high resistance, short to ground, or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 7 | ||||||
7 | Test the right air temperature position signal circuit of the right air temperature actuator for an open, a high resistance, short to ground, or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 8 | ||||||
8 | Test the right air temperature control circuit of the right air temperature actuator for an open, a high resistance, short to ground, or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 9 | ||||||
9 |
Important: The right air temperature actuator connector and the HVAC controller connector must be connected to correctly perform the test.
Does the right air temperature actuator drive shaft rotate and does the voltage change? | -- | Go to Step 10 | Go to Step 11 | ||||||
10 |
Does the voltage measure near the specified value when airflow moves toward Full Cold decreasing , near the specified value when airflow moves toward Full Hot increasing, and near the specified value when stationary? | 0 V decreasing 5 V increasing 2.5 V stationary | Go to Step 11 | Go to Step 12 | ||||||
11 | Inspect for poor connections at the harness connector of the right air temperature actuator. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 13 | ||||||
12 | Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 14 | ||||||
13 | Replace the right air temperature actuator. Refer to Temperature Valve Actuator Replacement - Right Side . Did you complete the replacement? | -- | Go to Step 15 | -- | ||||||
14 | Replace the HVAC control module. Refer to HVAC Control Module Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- | ||||||
15 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 | ||||||
