How to Troubleshoot the Heating and A/C Systems (Without Climate Control)

How to Troubleshoot the Heating and A/C Systems

How to Check for DTCs With the HDS

NOTE:

- There are three methods used to check for DTCs. The recommended method is to use the Honda Diagnostic System (HDS) with the appropriate software, plugged into the data link connector (DLC).
- The second method is to run the self-diagnostic function built into the HVAC control unit.
- The third method is to use B-CAN system diagnosis test mode A Troubleshooting - B-CAN System Diagnosis Test Mode A.

1. Make sure the ignition switch is in LOCK (0).

2. Connect the HDS to the DLC (A) located under the driver's side of the dashboard.

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

4. Make sure the HDS communicates with the vehicle and the HVAC control unit. If it does not, go to the DLC circuit troubleshooting Testing and Inspection.

5. Select HVAC/CLIMATE CONTROL in the BODY ELECTRICAL menu.

6. Select INSPECTION in the HVAC/CLIMATE CONTROL menu.

7. Select CLIMATE CONTROL SELF TEST in the INSPECTION menu.

8. Check for DTCs. If any DTCs are indicated, write down the DTCs, then go to the indicated DTC troubleshooting.

NOTE:

- After troubleshooting, clear the DTCs with the HDS.
- For specific operations, refer to the user's manual that came with the HDS.

How to Use the HVAC Control Unit Self-Diagnostic Function Without the HDS

The HVAC control unit has a self-diagnostic function for heating, ventilation, and air conditioning system. To run the self-diagnostic function, do the following:

1. Turn the ignition switch to LOCK (0), and then back to ON (II).

2. Set the FAN speed to ON with the ON/OFF button, and the FRONT TEMPERATURE CONTROL dial to Max Cool.

3. Set the FAN speed to OFF with the ON/OFF button, and the FRONT MODE CONTROL button to VENT.

4. Press and hold the RECIRCULATION button, then within 10 seconds press and release the REAR WINDOW DEFOGGER/MIRROR DEFOGGER button five times. Release the RECIRCULATION button; the recirculation indicator blinks two times, then the self-diagnosis begins.

NOTE:

- The self-diagnostic test could take up to two minutes to run.
- The blower motor should run at various speeds regardless of what the panel is displaying.
- If there is any problem in the system after the self-diagnostic function is finished, the recirculation indicator blinks Diagnostic Trouble Code (DTC) 1 through 8. In the case of multiple problems, the recirculation indicator blinks in order with the lowest number DTC repeatedly.
- If no DTCs are found, the indicator does not blink.

Canceling the Self-Diagnostic Function

- Turn the ignition switch to LOCK (0), to cancel the self-diagnostic function. After completing the repair work, run the self-diagnostic function again to make sure that there are no other DTCs.

Clear the DTCs

When the problem is repaired, DTCs will automatically clear.

Max Cool Position Function

When the MAX A/C button is pressed, the HVAC control unit will automatically select the recirculation mode and turn the A/C on.