Reading and Clearing Diagnostic Trouble Codes
How to Troubleshoot the Climate Control System
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 to 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 climate control unit. If it doesn't, troubleshoot the DLC circuit DLC Circuit Troubleshooting (PGM-FI System).
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 the indicated DTC troubleshooting. 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 HVAC control unit. If there is a communicate problem with the HDS, go to B-CAN system diagnosis test mode A Troubleshooting - B-CAN System Diagnosis Test Mode A.
1. Make sure the ignition switch to 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 climate control unit. If it doesn't, troubleshoot the DLC circuit DLC Circuit Troubleshooting (PGM-FI System).
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 Self-Diagnostic Function without the HDS
The climate control unit has a self-diagnostic function. To run the self-diagnostic function, do the following:
1. Turn the ignition switch to LOCK (0) and then back to ON (II).
2. Press and hold the OFF button. While pressing the REAR WINDOW DEFOGGER/MIRROR HEATER button five times within 10 seconds, then release the OFF button and the self-diagnostic will begin.
NOTE:
- The blower motor will run at various speeds regardless of what the panel is displaying.
- If there is a problem with the system, it will flash 88, or 88 AUTO or 88 A/C, and one or more of the 14 indicator segments (A through P). Refer to checking for DTCs.
- If there are no problems detected, the segments will not illuminate, and the system will appear to be turned off.
Canceling the Self-Diagnostic Function
- Turn the ignition switch to LOCK (0) to cancel the self-diagnostic function. After completing repair work, run the self-diagnostic function again to make sure that there are no other DTCs.
Trouble Code Memory Function
The trouble code that the climate control unit memorizes can be displayed. To run the trouble code memory function, do the following:
1. Turn the ignition switch to LOCK (0) and then back to ON (II).
2. Press and hold the AUTO button, then press and hold the OFF button.
3. The trouble code memorized in the climate control unit is displayed.
Checking for DTCs
The temperature display indicates single or multiple DTCs. If no DTCs are present, the indicator remains blank.
NOTE: If indicator segments A, C, D, E, G, J, and the AUTO indicator or the A/C indicator are on at the same time, there may be an open in the climate control unit ground circuit.
Displaying Sensor Inputs at the Climate Control Unit
The climate control unit receives sensor inputs and has a mode that displays them. This mode shows you what the climate control unit is receiving from each of the sensors, one at a time, and it can help you determine if a sensor is faulty.
Checks Before Using the Sensor Input Display Mode
1. Turn the ignition switch to ON (II), and check the recirculation door function; press the recirculation button to switch from FRESH to RECIRC. The air volume and sound should change slightly.
2. Set the temperature control knob to the desired test temperature. When selecting the test temperature, note these items:
- "Lo" temperature setting will default to MAX COOL, VENT, and RECIRC (A/C ON) or FRESH (A/C OFF).
- "Hi" temperature setting will default to MAX HOT, HEAT or HEAT/DEF (switches between HEAT, HEAT/DEF according to the outside temperature sensor reading), and FRESH.
- 58 through 86 °F ( or 16 through 28°C) settings will use the automatic climate control logic.
3. Turn the ignition switch to LOCK (0).
Run the Sensor Input Display Mode
1. Turn the ignition switch to LOCK (0).
2. Press and hold both the AUTO and RECIRCULATION buttons, then start the engine.
3. After the engine starts, release both buttons. The display panel control unit will flash the sensor number and then the value for that sensor. Record the value displayed.
4. To advance to the next sensor, press the REAR WINDOW DEFOGGER/MIRROR HEATER button.
NOTE:
- The mode positioning will be displayed by BIT. Check the mode motor positioning by using the mode motor code information.
- The sensor values will be displayed in degrees Celsius (°C) or an alphanumeric code. Use the chart to convert the value to degrees Fahrenheit (°F).
- If the sensor value displays "Er", this indicates there is an open or short in the circuit or sensor. Check for DTCs using the HDS, or refer to checking DTCs by DTC indication to check for DTCs.
- If necessary, compare the sensor input display to a like, known-good vehicle under the same test conditions.
- If the sensor displayed value is out of the normal range, refer to the sensor test or substitute a known-good sensor, and recheck.
- Target vent temperature air out (TAO) is the value calculated by the climate control unit. It is determined by the conditions of the TEMP DIAL position, the outside air temperature, the in-car temperature, and the solar radiation.
Celsius to Fahrenheit Conversion Table
Alphanumeric Conversion Table
Mode Motor Code Information
Code information on the mode motor is displayed by combining regulated segments.
- To cancel the sensor input display mode, press the AUTO button or turn the ignition switch to LOCK (0).