Fault Code 15
Fault Code 15Heater Matrix Temperature Sensor
- Sensor, harness or Air Conditioning Control Module (A/CCM) open circuit.
- Sensor, harness or A/CCM short circuit to ground.
This sensor measures the temperature of the heater matrix.
If the signal on pin 28 (12-way connector) remains at less than 1 volt, suspect either a short circuit to ground on the signal wire or an open circuit on the 5 volt supply to the sensor. If the signal on pin 28 rises to approximately 5 volts then suspect an open circuit on the sensor ground.
Check the voltage, against the graph below (Fig 1), measured between pin 28 (12-way connector) and pin 19 (22-way connector) A/CCM.
Characteristics Of Motorized In-Car Aspirator, Fig.1:
If the voltage is within the set limits, the system is operating correctly.
A resistance check can be carried out on the sensor and should conform with the figures below, measured between pin 28 (12-way connector) and pin 19 (22-way connector) A/CCM.
0 °C 4.6 - 5.1 K Ohm
15 °C 2.1 - 2.6 K Ohm
If the resistance is outside the set limits, renew the sensor.
NOTE: The resistance should continue to decrease as the temperature increases and vice versa.
Inspect sensor harness for open circuit or short circuit to ground. repair as necessary.
If the voltage is outside the set limits, renew the A/CCM.