The ambient temperature sensor is a thermistor that controls the signal voltage to the heater and A/C programmer. The heater and A/C programmer supplies the voltage on CKT 735. When the sensor is cold, the following conditions exist:
• | The resistance is high. |
• | The heater and A/C programmer reads a high signal voltage at pin C8. |
When the sensor warms, the following actions occur:
• | The resistance is reduced. |
• | The signal voltage is pulled low through CKT 407. |
The signal voltage varies between 5 V (open circuit) and 0 V (short circuit).
Turn the ignition to the ON position.
If the ambient temperature drops below approximately -38°C (-36°F), ignore this DTC.
• | Dashes are displayed on the IPC or CCP (with the analog IPC) temperature display. |
• | A default value of 15°C (60°F) is used in order to allow the operation of the A/C system. |
If an intermittent DTC B1310 is set, connect the Scan Tool and select the following options:
• | Data list |
• | Opens/shorts data |
• | Observe the reading |
Manipulate the wiring while observing the Scan Tool . If a failure is induced, the reading will jump. Inspect for a faulty terminal contact, and an obstructed or defective sensor.
The Scan Tool displays the ambient temperature. Jumping the harness connector determines whether the wiring or the sensor is the cause.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
Did you perform the Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check | |
Did the DTC change from B1310 and B1311? | -- | Go to Step 4 | Go to Step 3 | |
3 | Measure the voltage at terminal B. Is the measured voltage approximately equal to the specified value? | 5 V | Go to Step 6 | Go to Step 5 |
4 |
Did you complete the repair? | -- | Go to Diagnostic System Check | -- |
5 | Measure the voltage at terminal C8. Refer to Measuring Voltage in Wiring Systems. Is the measured voltage approximately equal to the specified value? | 5 V | Go to Step 8 | Go to Step 7 |
6 |
Did you complete the repair? | -- | Go to Diagnostic System Check | -- |
7 |
Did you complete the repair? | -- | Go to Diagnostic System Check | -- |
8 |
Did you complete the repair? | -- | Go to Diagnostic System Check | -- |