DTC 06

Circuit Description:

The in-vehicle temperature sensor is a thermistor used to control the signal voltage to the heater and A/C programmer.

The programmer supplies a voltage (about 5 volts/reference) on CKT 734 to the sensor. When the inside air temperature is cold, the sensor (thermistor) resistance is high, therefore, the programmer will see a high signal voltage. If the inside air temperature is high, the sensor (thermistor) resistance is low, therefore, the heater and A/C programmer will see a low voltage.

Test Description:

Number(s) below refer to circled number(s) on the diagnostic chart.

1. This test will determine if the sensor is open or shorted internally. If the temperature/resistance relationship is not within the specified range, the sensor should be replaced.
2. This test will determine if there is an open or short in the entire circuit. If no open or short is present and the temperature/resistance relationship is within the specified range, the HVAC programmer should be replaced.

Diagnostic Aids:

If resistance readings are within range at the sensor but out of range at the HVAC programmer, check all harness connections between the sensor and the HVAC programmer.

If no problem is found after performing Steps 1 and 2, check for an intermittent open or short while moving the wire harness and monitoring sensor resistance at the HVAC programmer harness terminals "C16" and "D15".