B1316

CIRCUIT DESCRIPTION
The in-vehicle temperature sensor is a thermistor that controls signal voltage to the Air Conditioning Programmer (ACM). The ACM applies voltage on CKT 734. When the sensor is cold resistance is high, therefore the ACM will see high signal voltage at pin "D9." As the sensor warms, the resistance becomes less and signal voltage is pulled low through the sensor ground, CKT 407. This signal voltage varies between 5V (open circuit) and 0V (short circuit).

TEST CONDITION(S)
1. Ignition "ON."
2. Outside air temperature reads above -20°F.
3. DTC B1310 or B1311 not set.

ACTION TAKEN
1. A substitute temperature reading of 24°C (75°F) is used to allow continued operation.

TEST DESCRIPTION
1. Scan tool displays in-vehicle temperature. jumpering the harness connector determines if the wiring or sensor is the cause.

NOTES ON INTERMITTENT
If an intermittent DTC B1316 is being set, connect Scan tool, select ACM Data list, Open/Shorts Data and note reading.

Manipulate the wiring while observing scan tool If failure is induced, the reading will jump. Check for poor terminal contact, obstructed, or defective sensor.