Circuit Description
The left A/C temperature sensor is a thermistor that controls signal voltage to the heater and A/C programmer. The heater and A/C programmer supplies voltage on CKT 516. When the sensor is cold, the resistance is high and the heater and A/C programmer senses a high signal voltage at terminal B6, connector C2. When the sensor warms, resistance is reduced and the signal voltage is pulled low through CKT 61. Signal voltage varies from 5 V (open circuit) to 0 V (short circuit).
Conditions for Setting the DTC
| • | The ignition is on. |
| • | The circuit is opened or shorted. |
Action Taken When the DTC Sets
| • | A default value of 128 counts and 24 degrees C (75 degrees F) will be used by the heater and A/C programmer. |
| • | The default valve allows the system to operate. |
| • | If air delivery is on A/C or bi-level, the air mix one door will cycle between full cold and full hot. |
Conditions for Clearing the DTC
| • | Use a Scan Tool . |
| • | A history DTC will clear after 50 consecutive ignition cycles have occurred without a malfunction. |
| • | Battery voltage to the body control module is interrupted. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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Perform the Body Control Module (BCM) Diagnostic System Check before continuing with the diagnosis of this DTC.
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This step ensures that the DTC was not set in error.
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This step determines whether the cause of the malfunction is the sensor or an open or short in a circuit.
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The Scan Tool tests for proper sensor operation. Clear all of the DTCs after the repair procedure is complete.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Did you perform the BCM Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check in Body Control System | |
2 |
Is the specified voltage measured? | 4.5-5.5 V | Go to Step 3 | Go to Step 4 |
Did the DTC reset? | -- | Go to Step 4 | ||
Did the left A/C temperature sensor voltage decrease? | -- | Go to Step 5 | Go to Step 6 | |
5 | Replace the sensor. Refer to Air Conditioning (A/C) Temperature Sensor Replacement . Is the repair complete? | -- | Go to Step 9 | -- |
6 | Inspect CKT 61 (YEL) for an open or a short . Was an open or a short located? | -- | Go to Step 7 | Go to Step 8 |
7 |
Is the replacement complete? | -- | Go to Step 9 | -- |
8 | Repair the open or the short in CKT 61 (YEL). Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 9 | -- |
Is the A/C system operating properly? | -- | Go to Cooling Insufficient - Air Conditioning (A/C) Inoperative | -- |
