The inside air temperature sensor is a thermistor that controls the signal voltage to the heater and A/C programmer. The heater and A/C programmer supplies voltage on CKT 734. 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 D9. |
As the sensor warms, the following actions occur:
• | The resistance decreases. |
• | The signal voltage is pulled low through the sensor ground, CKT 407. |
The signal voltage varies between 5 V (open circuit) and 0 V (short circuit).
• | Turn the ignition to the ON position. |
• | The ambient air temperature reads above -29°C (-20°F). |
• | DTCs B1310 or B1311 are not set. |
A substitute temperature reading of 24°C (75°F) is used in order to continue the operation. As a result, the internal temperature may be overly warm or overly cold.
If an intermittent DTC B1316 is set, use a Scan Tool in order to select the following settings:
• | Data list |
• | Open/shorts data |
• | Observe the reading |
Manipulate the wiring while observing the Scan Tool . If a failure is induced, the reading will jump. Inspect for the following conditions:
• | Faulty terminal contact |
• | An obstructed or defective sensor |
The Scan Tool displays the inside air temperature. Jumping the harness connector determines if 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 | |
2 |
Did the DTC change from B1316 to B1317? | -- | Go to Step 4 | Go to Step 3 |
3 | Measure the voltage at terminal B. Refer to Measuring Voltage in Wiring Systems. 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? | -- | System OK | -- |
5 | Measure the voltage at terminal D9 of the heater and A/C programmer. 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 | Measure the voltage at cavity C of C205. Refer to Measuring Voltage in Wiring Systems. Is the measured voltage approximately equal to the specified value? | 5 V | Go to Step 10 | Go to Step 9 |
9 |
Did you complete the repair? | -- | Go to Diagnostic System Check | -- |
10 |
Did you complete the repair? | -- | Go to Diagnostic System Check | -- |