2007 Grand Cherokee WK Factory Service Manual 24 - HEATING & AIR CONDITIONING

77-EBL OUTPUT SHORTED HIGH





For a complete wiring diagram Refer to Section 8W.



Possible Causes
 
EBL RELAY SHORTED TO BATTERY
 
(C115) DEFOGGER RELAY CONTROL CIRCUIT SHORTED TO BATTERY
 
JUNCTION BLOCK
 
A/C HEATER CONTROL
 


NOTE: This DTC must be active for the results of this test to be valid. Do not perform this test if this DTC is stored. Refer to HVAC System Test (MTC) for stored DTC test procedures.



Diagnostic Test

1. CHECK THE EBL RELAY FOR A SHORT TO BATTERY



Turn the ignition off.
Install a known good relay in place of the EBL relay.
Turn the ignition on.
Actuate the Clear DTC function by performing the following:
Press the EBL mode switch on.
Actuate the Display DTC function by performing the following:

NOTE: The A/C status indicator displays active DTCs when the EBL status indicator is not illuminated and stored DTCs when the EBL status indicator is illuminated.


Read DTCs from the A/C status indicator.

Does the A/C status indicator display DTC 77?

Yes


No

2. CHECK FOR A SHORTED A/C HEATER CONTROL



Turn the ignition off.
Remove the replacement EBL relay.
Disconnect the A/C Heater Control C1 harness connector.
Turn the ignition on.
Measure the voltage of the (C115) Defogger Relay Control circuit.

Is the voltage above 0.2 volts?

Yes


No

3. CHECK THE (C115) DEFOGGER RELAY CONTROL CIRCUIT FOR A SHORT TO BATTERY



Turn the ignition off.
Disconnect the Junction Block C2 harness connector.
Turn the ignition on.
Measure the voltage of the (C115) Defogger Relay Control circuit.

Is the voltage above 0.2 volts?

Yes


No