Fault Code 33
Fault Code 33Cool Air Bypass Potentiometer
- Disconnect the FOOT servo yellow, 5-way connector.
- Test the 5 V supply to the potentiometer at the Air Conditioning Control Module (A/CCM), pin 9 (positive) and pin 2 (ground).
If there is no 5 volt supply, inspect the harness for open circuit or short circuit to ground. If no harness faults are apparent, renew the A/CCM.
NOTE: The A/CCM provides a common 5 V 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 9 and 2 at main unit connector, value should be 6 K Ohms ± 10% at 20 °C.
Measure the resistance from the potentiometer wiper (pin 3) to pins 9 and 2 respectively. Resistances should read:
Resistence Table:
If the resistance measured falls outside the said limits, renew the potentiometer.