Heating & A/C System: 34

34-EBL MODE SWITCH STUCK (MTC)

For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

Theory of Operation

The switch input changes when the switch is pushed down. A stored DTC 34 indicates that the EBL mode switch was stuck in a pushed position for more than 10 minutes, but has since returned to its normal state. An active DTC 34 indicates that the EBL mode switch is stuck in a pushed position. An active DTC 34 will prevent the control from performing certain diagnostic functions and it will prevent proper EBL mode switch and status indicator function.

- When Monitored:
With the ignition on.

- Set Condition:
If the EBL mode switch stays in a pushed position for more than 10 minutes.





1. INSPECT THE A/C HEATER CONTROL FOR DAMAGE
1. Inspect the A/C Heater Control for damage.

Is the A/C Heater Control damaged?

Yes

- Replace the A/C Heater Control.
- Perform the BODY VERIFICATION TEST Body Verification Test.

No

- Go To 2

2. INSPECT FOR OBJECT OR SUBSTANCE CAUSING THE EBL MODE SWITCH TO STAY OR STICK IN A PUSHED POSITION
1. Inspect the A/C Heater Control for anything that would cause the EBL mode switch to stay or stick in a pushed position.

Is anything present that would cause the EBL mode switch to stay or stick in a pushed position?

Yes

- Repair as necessary.
- Perform the BODY VERIFICATION TEST Body Verification Test.

No

- Go To 3

3. CHECK FOR NORMAL EBL MODE SWITCH AND STATUS INDICATOR FUNCTION
1. Turn the ignition on.
2. Press the EBL mode switch on and off several times while observing the EBL status indicator.

Does the EBL status indicator turn on and off with respect to the switch position?

Yes

- Go To 4

No

- Replace the A/C Heater Control.
- Perform the BODY VERIFICATION TEST Body Verification Test.

4. CHECK A/C HEATER CONTROL OPERATION BY ATTEMPTING TO RUN THE ACTUATOR CIRCUIT TEST/ DOOR CALIBRATION FUNCTION
1. If illuminated, turn off the A/C status indicator and the EBL status indicator.
2. Actuate the Actuator Circuit Test / Door Calibration Function by performing the following:
- Turn the blower control off.
- Press and hold the EBL mode switch down and then turn the blower control on. Continue to hold the EBL mode switch down until the EBL status indicator begins flashing. Then, release the EBL mode switch.

3. While the test / function is running, the EBL status indicator will flash once per second. If the test / function passes, the EBL status indicator will stop flashing. If the test / function fails, the A/C and EBL status indicators will flash alternately.

Did the A/C Heater Control run the test / function?

Yes

- Perform the BODY VERIFICATION TEST Body Verification Test.

No

- Replace the A/C Heater Control.
- Perform the BODY VERIFICATION TEST Body Verification Test.