Circuit Description
The instrument panel integration module (IPM) monitors the outside air temperature via a temperature sensor. 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 displays the outside air temperature on the heater A/C control head.
Conditions for Running the DTC
The ignition is turned ON.
Conditions for Setting the DTC
The IPM 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 2.50 V (128 counts) will be used for the sensor data by the IPM. The temperature displayed on the scan tool, 16°C (60°F) in the HVAC Sensors data list, will be the default value. The actual sensor reading will be displayed on the scan tool in the Open/Short data list. |
| • | The heater A/C control head will display " - -" for outside air temperature when OFF. |
| • | The heater A/C control head will display the set temperature when ON. |
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 number(s) below refer to the step number(s) 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.
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 Outside Air Temp parameter is within the specified range? | 0.09-4.90 V | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
Does the scan tool indicate that the Outside 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 Outside Air Temp parameter is less than the specified value? | 0.09 V | Go to Step 8 | Go to Step 6 | |
5 | Test the signal circuit of the ambient air temp 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 signal circuit of the ambient air temp 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 ground circuit of the ambient air temp 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 ambient air temp 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 ambient air temp sensor. Refer to Ambient Temperature Sensor Replacement . Did you complete the replacement? | -- | Go to Step 12 | -- |
11 | Replace the IPM. 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 |
