Circuit Description
The instrument panel integration module (IPM) monitors the inside air temperature through the inside air temperature sensor. The inside air temperature sensor is a variable resistor. The IPM supplies 5 volts to the inside air temperature sensor signal circuit and provides a low reference circuit. When the air is cold, the sensor resistance and signal voltage are high. When the air is warm, the sensor resistance and signal voltage are low. The IPM requests A/C compressor clutch engagement and controls the left and right air temperature door positions in order to maintain the selected air temperature on the HVAC control module.
Conditions for Running the DTC
The ignition is turned ON.
Conditions for Setting the DTC
The IPM detects the inside air temperature sensor signal circuit is less than 0.09 volt (5 counts) or greater than 4.90 volts (250 counts).
Action Taken When the DTC Sets
A default value of 2.50 volts (128 counts) will be substituted for the inside air temperature sensor data by the IPM. The Inside Air Temp displayed on the scan tool, 24°C (76°F) in the HVAC Sensors data list, will be the default value. The Inside Air Temp displayed on the scan tool in the Open/Short Data list will be the actual value.
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. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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The operating range of the sensor is between 0.09-4.90 volts. If the scan tool displays a value between 0-.08 volt or 4.91-5.0 volts, then the sensor is performing outside of its designed limits.
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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.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: HVAC Schematics | ||||
1 | Did you perform the HVAC Diagnostic System Check? | -- | Go to Step 2 | |
Does the scan tool indicate that the Inside Air Temp parameter is within the specified range? | 0.09-4.90 V | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 | |
Does the scan tool indicate that the Inside Air Temp parameter is greater than the specified value? | 4.90 V | Go to Step 4 | Go to Step 5 | |
Does the scan tool indicate that the Inside Air Temp parameter is less than the specified value? | 0.09 V | Go to Step 8 | Go to Step 6 | |
5 | Test the inside air temperature sensor signal circuit of the inside air temperature 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 12 | Go to Step 9 |
6 | Test the inside air temperature sensor signal circuit of the inside air temperature 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 12 | Go to Step 7 |
7 | Test the low reference circuit of the inside air temperature sensor 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 12 | Go to Step 9 |
8 | Inspect for poor connections at the harness connector of the inside air temperature sensor. 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 12 | Go to Step 10 |
9 | Inspect for poor connections at the harness connector of the IPM. 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 12 | Go to Step 11 |
10 | Replace the inside air temperature sensor. Refer to Inside Air Temperature Sensor Replacement . Did you complete the replacement? | -- | Go to Step 12 | -- |
11 |
Important: : Perform the recalibration procedure for the replacement 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 12 | -- |
12 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
