Check for a loose wire or poor connection at climate control unit connector A (40P). If the connection is good, substitute a known-good climate
control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit See: Heating and Air
Conditioning/Control Assembly/Service and Repair/Climate Control Unit Removal/Installation.?
20. While measuring the voltage as described in step 19, reconnect these items individually and note the voltage reading each time:
- Driver's air mix control motor
- Passenger's air mix control motor
- Rear air mix control motor
- Humidity/in-car temperature sensor
- A/C pressure sensor
Does the voltage remain at about 5 V?
YES -
Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit See:
Heating and Air Conditioning/Control Assembly/Service and Repair/Climate Control Unit Removal/Installation.?
NO -
Replace the component that caused the voltage drop.?
B1235
DTC Troubleshooting: B1235 (L and AUTO)
DTC B1235 or DTC indicator L and AUTO:
A Problem in the Driver's Air Mix Control Linkage, Door, or Motor Circuit
1. Clear the DTCs with the HDS.
2. Turn the ignition switch to LOCK (0) and then back to ON (II).
3. Do the self-diagnostic function with the HDS or the climate control unit.
4. Check for DTCs.
Is DTC B1235 or L and AUTO indicated?
YES -
Go to step 5.
NO -
Intermittent failure, check for loose wires or poor connections in the driver's air mix control motor circuit.?
5. Turn the ignition switch to LOCK (0).
6. Test the driver's air mix control motor See: Heating and Air Conditioning/Testing and Inspection/Component Tests and General
Diagnostics/Driver's Air Mix Control Motor Test.
Is the driver's air mix control motor OK?
