Fault Code 31
Fault Code 31LH Fresh/Recirc. Potentiometer
Test the 5 volt supply to potentiometer between pin 1 and pin 2 (ground) of the blower harness.
If there is no 5 V supply, inspect the harness for open circuit or short circuit to ground. If no harness faults are apparent, renew the Air Conditioning Control Module (A/CCM).
NOTE: The A/CCM provides a common 5V output and ground to all servos, i.e. all servo potentiometers are fed by a 5 V rail. If all servos are inoperable check the A/CCM outputs and harness, renew the A/CCM.
Check resistance between potentiometer connector pins 1 and 2 at blower harness connector, value should be 6 K Ohms ± 10% at 20 °C.
Measure the resistance from the potentiometer wiper (pin 6) to pins 1 and 2 respectively. Resistances should read:
Resistence Table:
If the resistance measured falls outside the said limits, renew the servo unit.