How To Troubleshoot The Heating And A/C Systems
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), then go to B-CAN system diagnosis test mode A Troubleshooting - B-CAN System Diagnosis Test Mode A.
- The second method is to run the self-diagnostic function built into the HVAC control unit.
- The third method is to use the B-CAN system diagnostic test mode 1 and mode 2 without the HDS Troubleshooting - B-CAN System Diagnosis Test Mode 1 And Test Mode 2 (Without The HDS).
1. Make sure the ignition switch is in LOCK (0).
2. Connect the HDS to the data link connector (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 MICU. If it doesn't, troubleshoot the DLC circuit Testing and Inspection.
5. Select HVAC/CLIMATE CONTROL in the BODY ELECTRICAL menu.
6. Select DTCs in the HVAC/CLIMATE CONTROL menu.
7. Check for DTCs. If any DTCs are indicated, write down the DTCs, then go to troubleshooting B-CAN system diagnosis test mode A Troubleshooting - B-CAN System Diagnosis Test Mode A. If no DTCs are indicated, refer to symptom 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 Self-Diagnostic Function with the HDS
NOTE: This method is only available if the HDS can communication with the MICU. If there is a communication problem with the HDS, go to B-CAN system diagnostic 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 data link connector (DLC).
3. Turn the ignition switch to ON (II).
4. Make sure the HDS communicates with the vehicle and the MICU. If it doesn't, troubleshoot the DLC circuit 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 OFF with FAN ON/OFF button, the TEMPERATURE CONTROL dial on Max Cool, and select the VENT mode.
3. Turn the ignition switch to LOCK (0) and then back to ON (II).
4. Press and hold the RECIRCULATION CONTROL button, then within 10 seconds press and release the REAR WINDOW DEFOGGER/MIRROR DEFOGGER button five times. Release the RECIRCULATION CONTROL button; the recirculation indicator blinks two times, then the self-diagnostic 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 9. 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.