Circuit Description
The instrument panel integration module (IPM) commands recirculation actuator movement with one of three voltage signals applied to the recirculation door control circuit. A low voltage of 0 volts moves the recirculation door toward the recirculation position. 2.5 volts stops the actuator. 5 volts moves the recirculation door toward the ambient air position. The IPM determines the current position of the actuator by monitoring the feedback voltage of the recirculation door position signal circuit. The feedback potentiometer position is a function of the actuator position. The IPM controls the recirculation 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. The IPM will perform a travel range comparison of the calculated minimum and maximum extremes of the actuator to the calibrated minimum and maximum range extremes within the IPM. If the calculated range does not equal the calibrated expected range, the actuator will be considered not calibrated and the DTC will set. The IPM will also perform a continuous test on the current feedback value. If the feedback value does not equal or fall within the calibrated range the DTC will set.
Conditions for Running the DTC
| • | The ignition is turned ON. |
| • | The IPMs keep alive memory (KAM) battery power must be interrupted to run the range check. This can be accomplished with the scan tool by commanding HVAC Recalibration in Heating and Air Conditioning Special Functions. |
Conditions for Setting the DTC
| • | The IPM detects the signal circuit is less than 0.25 V (13 counts) or greater than 4.80 V (245 counts). |
| • | The recirculation actuators total travel range (max-min) is less than or greater than the calibrated limits. |
Action Taken When the DTC Sets
| • | A default value of will be substituted for the recirculation door position data by the IPM. |
| • | Each time the ignition switch is turned ON the IPM will recheck the actuator travel range. |
| • | The IPM will continue to make use of whatever travel range is still available. |
Conditions for Clearing the DTC
| • | The DTC will become history if the IPM 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
| • | The range fault can only be detected following a check of the actuator travel range. The actuator travel range check can only be initiated by disrupting power to the IPM. |
| • | The calibration limit is 165-195 counts. An actual range below this limit suggests an obstruction or something stuck in the door limiting travel. An actual range above this limit suggests an over travel condition such as damaged or missing foam seals. |
| • | A damaged or broken air temperature door and or actuator can cause this DTC to set by allowing the actuator shaft to rotate unrestricted to its internal stop. The internal stops are outside of the feedback potentiometer's working range of 0-250. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Tests for the proper operation of the circuit in the high voltage range.
-
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.
-
Tests for a short to ground in the 5 volt reference circuit.
Step | Action | Values | Yes | No | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: HVAC Schematics | ||||||||||||||||
1 | Did you perform the HVAC Diagnostic System Check? | -- | Go to Step 2 | |||||||||||||
2 |
Does the scan tool indicate that the Air Inlet Dr. Actual parameter is within the specified range? | 0.25-4.75 V | Go to Step 3 | Go to Step 4 | ||||||||||||
3 |
Does the result of the calculation indicate that the actual travel of the recirculation actuator is within the specified range? | 165-195 counts | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 14 | ||||||||||||
4 |
Does the scan tool indicate that the Air Inlet Dr. Actual parameter changes when the recirculation actuator is commanded from Recirc. to Outside? | -- | Go to Step 5 | Go to Step 6 | ||||||||||||
5 | Inspect the recirculation door for a condition allowing excessive travel of the actuator. Did you find and correct the condition? | -- | Go to Step 23 | Go to Diagnostic Aids | ||||||||||||
Does the scan tool indicate that the Air Inlet Dr. Actual parameter is greater than the specified value? | 4.75 V | Go to Step 7 | Go to Step 11 | |||||||||||||
Does the scan tool indicate that the Air Inlet Dr. Actual parameter is less than the specified value? | 0.25 V | Go to Step 8 | Go to Step 12 | |||||||||||||
Does the scan tool indicate that the Air Inlet Dr. Actual parameter is greater than the specified value? | 4.75 V | Go to Step 10 | Go to Step 9 | |||||||||||||
9 | Test the 5 volt reference circuit of the recirculation actuator 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 23 | Go to Step 12 | ||||||||||||
10 | Test the 5 volt reference circuit of the recirculation actuator 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 23 | Go to Step 11 | ||||||||||||
11 | Test the recirculation door position signal circuit of the recirculation actuator 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 23 | Go to Step 12 | ||||||||||||
12 | Test the a recirculation door position signal circuit of the recirculation actuator 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 23 | Go to Step 13 | ||||||||||||
13 | Test the low reference circuit of the recirculation 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 23 | Go to Step 20 | ||||||||||||
14 | Test the ignition 3 voltage circuit of the recirculation actuator for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 23 | Go to Step 15 | ||||||||||||
15 | Test the recirculation door control circuit of the recirculation actuator for an open, high resistance, short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 23 | Go to Step 16 | ||||||||||||
16 |
Important: Ensure that the recirculation actuator connector and the instrument panel integration module connector are connected during this step in order to avoid misdiagnosis.
Does the recirculation actuator drive shaft rotate and do the counts change? | -- | Go to Step 17 | Go to Step 19 | ||||||||||||
17 |
Does the voltage measure near the specified value for each commanded state? | 0 V recirc. 5 V outside 2.5 V stationary | Go to Step 18 | Go to Step 20 | ||||||||||||
18 | Inspect the recirculation door and the recirculation actuator for the following conditions:
Did you find and correct the condition? | -- | Go to Step 23 | Go to Diagnostic Aids | ||||||||||||
19 | Inspect for poor connections at the harness connector of the recirculation 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 23 | Go to Step 21 | ||||||||||||
20 | Inspect for poor connections at the harness connector of the instrument panel integration 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 23 | Go to Step 22 | ||||||||||||
21 |
Important: : Perform the recalibration procedure for the recirculation actuator. Replace the recirculation actuator. Refer to Recirculation Actuator Replacement . Did you complete the replacement? | -- | Go to Step 23 | -- | ||||||||||||
22 |
Important: : Perform the recalibration procedure for the instrument panel integration module. Replace the instrument panel integration module. Refer to Instrument Panel Module Replacement in Body Control System. Did you complete the replacement? | -- | Go to Step 23 | -- | ||||||||||||
23 |
Does the DTC reset? | -- | Go to Step 2 | System OK | ||||||||||||
