B1314

CIRCUIT DESCRIPTION

The evaporator inlet temperature sensor is a thermistor that controls signal voltage to the heater and A/C programmer. The heater and A/C programmer applies voltage on CKT 731. When sensor is cold, its resistance is high, and the heater and A/C programmer will receive a high signal voltage at pin D15. When sensor warms, the resistance becomes less and the signal voltage is pulled low through CKT 407. This signal voltage varies between 5V (open circuit) and 0V (short circuit).

TEST CONDITION(S)

1. Ignition ON.

ACTION TAKEN

1. A/C compressor clutch is not allowed to engage.
2. IPC displays SERVICE A/C SYSTEM - A/C COMPRESSOR OFF.
3. A default temperature reading of 6°C (43°F) will be implemented.

TEST DESCRIPTION

1. Scan tool displays low side temperature. Jumping the hamess connector determines if the wiring or sensor is the cause.

NOTES ON INTERMITTENCE

If an intermittent DTC B1314 is being set connect scan tool, and select 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, and an obstructed or defective sensor.