Circuit Description
The air inlet door motor is an electronic actuator stepper motor with a feedback potentiometer. The heater and A/C programmer determines the position of the door motor based on the voltage from the potentiometer. When the airflow is being recirculated, the voltage is low. When outside air is being admitted, voltage is high. The heater and A/C programmer controls the air inlet door motor to position the air inlet door in either the recirc or the fresh air positions as selected by the vehicle occupants.
Conditions for Running the DTC
The ignition is turned ON.
Conditions for Setting the DTC
The heater and A/C programmer detects the signal circuit is less than 0.09 V (5 counts) or greater than 4.90 V (250 counts).
Action Taken When the DTC Sets
| • | A default value of 0.78 V (40 counts) will be used for the sensor data by the heater and A/C programmer. |
| • | The air inlet door will be set to the outside air position. |
Conditions for Clearing the DTC
| • | The DTC will become history if the heater and A/C programmer no longer detects a failure. |
| • | The history DTC will clear after 50 fault free ignition cycles. |
| • | The DTC can be cleared with a scan tool. |
Diagnostic Aids
| • | A disconnected or broken door may also set this DTC by allowing the actuator to travel to its internal stops (overtravel condition). |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
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Tests for the proper operation of the circuit in the high voltage range.
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Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.
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Tests for a short to ground in the 5 volt reference circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the HVAC Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check |
2 |
Does the scan tool indicate that the Air Inlet Dr Actual parameter is within the specified range? | 0.09-4.90 V | Go to Diagnostic Aids | Go to Step 3 |
3 |
Does the scan tool indicate that the Air Inlet Dr Actual parameter changes when the Air Inlet Door Position is commanded from Outside to Recirc? | -- | Go to Step 12 | Go to Step 4 |
Does the scan tool indicate that the Air Inlet Dr Actual parameter is greater than the specified value? | 4.90 V | Go to Step 5 | Go to Step 9 | |
Does the scan tool indicate that the Air Inlet Dr Actual parameter is less than the specified value? | 0.09 V | Go to Step 6 | Go to Step 10 | |
Does the scan tool indicate that the Air Inlet Dr Actual parameter is greater than the specified value? | 4.90 V | Go to Step 8 | Go to Step 7 | |
7 | Test the 5 volt reference circuit of the air inlet door position sensor for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 |
8 | Test the 5 volt reference circuit of the air inlet door position sensor for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 13 |
9 | Test the signal circuit of the air inlet door position sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 |
10 | Test the signal circuit of the air inlet door position sensor for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 11 |
11 | Test the motor ground circuit of the air inlet actuator for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 |
12 | Inspect the air inlet door for a condition allowing excessive travel of the actuator. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 13 |
13 | Inspect for poor connections at the harness connector of the air inlet 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 17 | Go to Step 15 |
14 | Inspect for poor connections at the harness connector of the heater and A/C programmer. 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 17 | Go to Step 16 |
15 | Replace the air inlet actuator. Refer to Air Inlet Actuator Replacement . Did you complete the replacement? | -- | Go to Step 17 | -- |
16 | Replace the heater and A/C programmer. Refer to Programmer Replacement . Did you complete the replacement? | -- | Go to Step 17 | -- |
17 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
