2010 Acura Truck MDX V6-3.7L Page 95

3. Do the self-diagnostic function with the HDS or the climate control unit.

4. Check for DTCs.

Is DTC B1228 or D and AUTO indicated?

YES -

Go to step 5.

NO -

Intermittent failure.?

5. Turn the ignition switch to LOCK (0).

6. Remove the outside air temperature sensor See: Heating and Air Conditioning/Ambient Temperature Sensor / Switch HVAC/Service and

Repair, and test it See: Heating and Air Conditioning/Testing and Inspection/Component Tests and General Diagnostics/Outside Air

Temperature Sensor Test.

Is the outside air temperature sensor OK?

YES -

With the outside air temperature sensor disconnected, go to step 7.

NO -

Replace the outside air temperature sensor See: Heating and Air Conditioning/Ambient Temperature Sensor / Switch HVAC/Service and Repair.?

7. Disconnect climate control unit connector A (40P).

8. Check for continuity between climate control unit connector A (40P) terminal No. 28 and body ground.

Is there continuity?

YES -

Repair a short to body ground in the wire between the climate control unit and the outside air temperature sensor.?

NO -

Go to step 9.

9. Check for continuity between climate control unit connector A (40P) terminals No. 8 and No. 28.

2010 Acura Truck MDX V6-3.7L Page 71

3. Do the self-diagnostic function with the HDS or the climate control unit.

4. Check for DTCs.

Is DTC B1223 or M and MODE indicated?

YES -

Go to step 5.

NO -

Intermittent failure, check for loose wires or poor connections in the rear blower motor circuit.?

5. Turn the ignition switch to LOCK (0).

6. Check the No. 2 (RR BLOWER) (30 A) fuse in the main under-hood fuse box, and the No. 30 (10 A) fuse in the under-dash fuse/relay

box.

Are the fuses OK?

YES -

Go to step 7.

NO -

Replace the fuse(s), and recheck. If fuse(s) blow again, check for a short in the No. 2 (RR BLOWER) (30 A) and No. 30 (10 A) fuse(s) circuit.?

7. Connect rear blower motor 2P connector terminal No. 2 to body ground with a jumper wire.

8. Turn the ignition switch to ON (II).

Does the rear blower motor run at high speed?

YES -

Go to step 9.

NO -

Go to step 24.

9. Turn the ignition switch to LOCK (0).

10. Disconnect the jumper wire.

11. Disconnect the rear power transistor 4P connector.

12. Check for continuity between rear power transistor 4P connector terminal No. 2 and body ground.

2010 Acura Truck MDX V6-3.7L Page 53

3. Do the self-diagnostic function with the HDS or the climate control unit.

4. Check for DTCs.

Is DTC B1231 or G and AUTO indicated?

YES -

Go to step 5.

NO -

Intermittent failure, check for loose wires or poor connections in the front evaporator temperature sensor circuit.?

5. Turn the ignition switch to LOCK (0).

6. Remove the front evaporator temperature sensor See: Heating and Air Conditioning/Evaporator Temperature Sensor / Switch/Service and

Repair/Front Evaporator Temperature Sensor Replacement, and test it See: Heating and Air Conditioning/Evaporator Temperature Sensor /

Switch/Testing and Inspection.

Is the front evaporator temperature sensor OK?

YES -

With the front evaporator temperature sensor disconnected, go to step 7.

NO -

Replace the front evaporator temperature sensor See: Heating and Air Conditioning/Evaporator Temperature Sensor / Switch/Service and

Repair/Front Evaporator Temperature Sensor Replacement.?

7. Disconnect climate control unit connector A (40P).

8. Check for continuity between climate control unit connector A (40P) terminal No. 24 and front evaporator temperature sensor 2P connector

terminal No. 2.

Is there continuity?

YES -

Go to step 9.

NO -

Repair an open in the wire between the climate control unit and the front evaporator temperature sensor.?

9. Check for continuity between climate control unit connector A (40P) terminal No. 8 and front evaporator temperature sensor 2P connector

2010 Acura Truck MDX V6-3.7L Page 76

3. Do the self-diagnostic function with the HDS or the climate control unit.

4. Check for DTCs.

Is DTC B1236 or M and AUTO indicated?

YES -

Go to step 5.

NO -

Intermittent failure, check for loose wires or poor connections in the passenger's air mix control motor circuit.?

5. Turn the ignition switch to LOCK (0).

6. Test the passenger's air mix control motor See: Heating and Air Conditioning/Testing and Inspection/Component Tests and General

Diagnostics/Passenger's Air Mix Control Motor Test.

Is the passenger's air mix control motor OK?

YES -

Go to step 7.

NO -

Replace the passenger's air mix control motor See: Heating and Air Conditioning/Air Door/Air Door Actuator / Motor/Service and

Repair/Passenger's Air Mix Control Motor Replacement.?

7. Disconnect the passenger's air mix control motor 7P connector.

8. Disconnect climate control unit connector A (40P).

9. Check for continuity between the following terminals of climate control unit connector A (40P) and the passenger's air mix control motor 7P

connector.

Is there continuity?

YES -

Check for loose wires or poor connections at climate control unit connector A (40P) and at the passenger's air mix control motor 7P connector. If

the connections are 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.?

NO -

Repair an open in the wire(s) between the climate control unit and the passenger's air mix control motor.?