How To Troubleshoot The Climate Control System

How to Troubleshoot the Climate Control System

How to Check for DTCs with the HDS

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 climate 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 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 without the HDS

The climate control unit has a self-diagnostic function. To run the self-diagnostic function, do the following:

NOTE: Before troubleshooting the climate control system, refer to B-CAN system diagnosis test mode A troubleshooting Troubleshooting - B-CAN System Diagnosis Test Mode A, and the communication circuit self-diagnostic function test.

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

2. Press and hold the ON/OFF button. While holding the ON/OFF button, press the recirculation button five times within 10 seconds. Release the ON/OFF button, then the self-diagnostic begins. Wait for about one minute for the self-diagnostic to complete.

NOTE: The blower motor will run at various speeds regardless of what the panel is displaying.






- If there is any problem in the system, the temperature indicator will light up the segment (A through S) corresponding to the error. The temperature indicator will then alternate every second between displaying "88" (all segments lit) and the error code segment (A through S). To determine the meaning of the DTC, 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 malfunctions.

Checking for DTCs

The temperature display indicates single or multiple DTCs. If indicator segments A, C, E, G, J, and M are on at the same time, there may be an open in the sensor common ground wire. If no DTCs are present, the indicator remains blank.










Displaying Sensor Inputs at the Climate Control Unit

The climate control unit has a mode that displays sensor inputs it receives. 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.

Check These Items 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.
- "Hi" temperature setting will default to MAX HOT, DEF, and FRESH.
- 58 through 86 °F settings will use the automatic climate control logic.

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

To Run the Sensor Input Display Mode, Follow These Steps

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 the 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 recirculation button.

NOTE:

- The sensor values will be displayed in degrees Celsius (°C) or an alphanumeric code. Use the charts to convert the temperature to degrees Fahrenheit (°F) or convert the alphanumeric code to a numerical value.
- 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 use the climate control self-diagnostic function.
- If necessary, compare the sensor input display to a known-good vehicle under the same test conditions.
- If the sensor is out of the normal range, refer to the sensor test or substitute a known-good sensor, and recheck.






Celsius to Fahrenheit Conversion Table









Alphanumeric Conversion Table





5. To cancel the sensor input display mode, press the AUTO button or turn the ignition switch to LOCK (0).