Pinpoint Test J : The Defrost System Is Inoperative - EMTC (Electronic Manual Temperature Control)

J1 CHECK THE BCM (BODY CONTROL MODULE) REAR DEFROST SWITCH (R_DEFRST_SW) PID (PARAMETER IDENTIFICATION) OPERATION
- Ignition ON.
- Using a diagnostic scan tool, view BCM Parameter Identifications (PIDs).
- Monitor the BCM PID R_DEFRST_SW while pressing and releasing the rear window defrost switch.
Does the PID agree with the rear window defrost switch status?

Yes GO to J5

No If DTC B1013:23 is present, GO to J3If DTC B1013:23 is not present, GO to J2

J2 CHECK THE HVAC (HEATING, VENTILATION AND AIR CONDITIONING) MODULE (REAR WINDOW DEFROST SWITCH) GROUND CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect: HVAC Module C2357A .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2357A-13	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance less than 3 ohms?

Yes

GO to J3

No	REPAIR the circuit.

J3 CHECK THE BCM (BODY CONTROL MODULE) REAR DEFROST SWITCH (R_DEFRST_SW) PID (PARAMETER IDENTIFICATION) OPERATION

Ignition OFF.

Disconnect: HVAC Module C2357A .

Connect a fused jumper wire between:

Positive Lead	Measurement / Action	Negative Lead
C2357A-13	Courtesy of FORD MOTOR COMPANY	C2357A-16

Ignition ON.

Using a diagnostic scan tool, view BCM Parameter Identifications (PIDs).

Observe the BCM PID R_DEFRST_SW status.

Remove the fused jumper wire.

Observe the BCM PID R_DEFRST_SW status.

Did the PID state change when the fused jumper wire was removed?

Yes	INSTALL a new HVAC module. Refer to: Heating, Ventilation and Air Conditioning (HVAC) Control Module .

GO to J4

J4 CHECK THE REAR WINDOW DEFROST SWITCH CIRCUIT FOR AN OPEN OR SHORT TO GROUND

Ignition OFF.

Disconnect: BCM C2280E .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2280E-16	Courtesy of FORD MOTOR COMPANY	C2357A-16

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2280E-16	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance less than 3 ohms between the BCM and the HVAC module and greater than 10, 000 ohms between the BCM and ground?

Yes

GO to J9

No	REPAIR the circuit.

J5 CHECK FOR VOLTAGE TO THE REAR WINDOW DEFROST GRID

Ignition OFF.

Disconnect: Rear Window Defrost Grid C402A .

Start the engine.

Activate the rear window defrost switch.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C402A-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes	If the rear window defrost switch LED is illuminated, GO to J8If the rear window defrost switch LED is not illuminated, GO to Pinpoint Test L

GO to J6

J6 CHECK THE BCM (BODY CONTROL MODULE) VOLTAGE FEED FOR AN OPEN

Ignition OFF.

Disconnect: BCM C2280A .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2280A-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes

GO to J7

No	VERIFY BJB fuse 34 (20A) is OK, If OK, REPAIR the circuit. If not OK, REFER to the OEM Electrical Wiring Diagram Introduction to identify the possible causes of the circuit short.

J7 CHECK THE REAR WINDOW DEFROST GRID VOLTAGE CIRCUIT FOR AN OPEN OR SHORT TO GROUND

Ignition OFF.

Disconnect: BCM C2280C .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2280C-9	Courtesy of FORD MOTOR COMPANY	C402A-1

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2280C-9	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance less than 3 ohms between the BCM and the rear window defrost grid and greater than 10, 000 ohms between the BCM and ground?

Yes

GO to J9

No	REPAIR the circuit.

J8 CHECK THE REAR WINDOW DEFROST GRID GROUND CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect: Rear Window Defrost Grid C402B .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C402B-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance less than 3 ohms?

Yes	CARRY OUT the Grid Wire Test . REPAIR the rear window defrost grid or INSTALL a new rear window glass as necessary.

No	REPAIR the circuit.

J9 CHECK FOR CORRECT BCM (BODY CONTROL MODULE) OPERATION

Ignition OFF.

Inspect the BCM 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 BCM 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 Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new BCM. Refer to: Body Control Module (BCM) .

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