Pinpoint Test F: The Defrost System Does Not Shut Off Automatically

Refer to HEATED WINDOW for schematic and connector information.

Normal Operation and Fault Conditions

REFER to: Glass, Frames and Mechanisms - Vehicles With: SYNC 3/SYNC 3 Lite, Vehicles Without: SYNC - System Operation and Component Description .

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
HVAC B1C83:14	Rear Defog Relay: Circuit Short To Ground Or Open	This DTC sets when the HVAC module detects a short to ground or an open in the rear window heater relay control circuit.

Possible Sources

Wiring, terminals or connectors
BJB
HVAC module

F1 CHECK THE HVAC (HEATING, VENTILATION AND AIR CONDITIONING) MODULE OPERATION

Ignition OFF.

Disconnect: HVAC Module C2357A.

Disconnect: Heater Rear Window Element C4425B (LH).

Start the engine.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C4425B-1	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes

GO to F2

GO to F4

F2 CHECK THE REAR WINDOW DEFROST RELAY CONTROL CIRCUIT FOR A SHORT TO GROUND

Ignition OFF.

Disconnect: BJB C1035B.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1035B-38	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes

GO to F3

No	REPAIR the circuit.

F3 CHECK THE REAR WINDOW DEFROST RELAY OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C4425B-1	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the circuit.

GO to F5

F4 CHECK FOR CORRECT HVAC (HEATING, VENTILATION AND AIR CONDITIONING) MODULE OPERATION

Ignition OFF.

Disconnect and inspect all the HVAC module connectors.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins as necessary
- pushed-out pins - install new pins as necessary

Reconnect the HVAC module connectors and all previously disconnected rear window defrost system connectors. Make sure they seat and latch correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes

CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new HVAC module. REFER to: Heating, Ventilation and Air Conditioning (HVAC) Control Module - Vehicles With: Electronic Automatic Temperature Control (EATC) .

No	The system is operating correctly at this time. The concern may have been caused by poor connections. ADDRESS the root cause of any connector or pin issues.

F5 CHECK FOR CORRECT BJB (BATTERY JUNCTION BOX) OPERATION

Inspect the BJB connectors.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins as necessary
- pushed-out-pins - install new pins as necessary

Reconnect the BJB connectors and all other previously disconnected defrost system connectors. Make sure they seat and latch correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new BJB.

No	The system is operating correctly at this time. The concern may have been caused by poor connections. ADDRESS the root cause of any connector or pin issues.