2007 Commander XK Factory Service Manual 24 - HEATING & AIR CONDITIONING

34-EBL MODE SWITCH STUCK (MTC)

For a complete wiring diagram Refer to Section 8W.

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. For additional information about the A/C Heater Control's on-board diagnostics, refer to 24 - HEATING & AIR CONDITIONING - DIAGNOSIS AND TESTING.



Possible Causes
 
A/C HEATER CONTROL DAMAGED
 
OBJECT HOLDING EBL MODE SWITCH IN A PUSHED POSITION
 
SUBSTANCE CAUSING EBL MODE SWITCH TO GET STUCK IN A PUSHED POSITION
 
A/C HEATER CONTROL
 




Diagnostic Test

1. INSPECT THE A/C HEATER CONTROL FOR DAMAGE

Inspect the A/C Heater Control for damage.

Is the A/C Heater Control damaged?

Yes


No

2. INSPECT FOR OBJECT OR SUBSTANCE CAUSING THE EBL MODE SWITCH TO STAY OR STICK IN A PUSHED POSITION

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


No

3. CHECK FOR NORMAL EBL MODE SWITCH & STATUS INDICATOR FUNCTION

Turn the ignition on.
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


No

4. CHECK A/C HEATER CONTROL OPERATION BY ATTEMPTING TO RUN THE ACTUATOR CIRCUIT TEST/ DOOR CALIBRATION FUNCTION

If illuminated, turn off the A/C status indicator and the EBL status indicator.
Actuate the Actuator Circuit Test / Door Calibration Function by performing the following:
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


No