Pinpoint Test M: The Defrost System Will Not Shut Off Automatically - Fusion, Milan

Glass, Frames and Mechanisms

Pinpoint Tests

Pinpoint Test M: The Defrost System Will Not Shut Off Automatically - Fusion, Milan

Refer to Wiring Diagram Set 56, Heated Window for schematic and connector information. Diagrams By Number

Normal Operation

The rear window defrost relay (integral to the Smart Junction Box (SJB)), receives power from circuit SBB06 (BN/RD). When the rear window defrost switch (integral to the HVAC module) is pressed, a signal is sent to the SJB through circuit CH122 (WH/OG). Once the SJB receives the signal to turn on the rear window defrost, the SJB grounds the rear window defrost relay coil, which sends power to the rear window defrost grid through circuit CLS38 (VT/WH).

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- SJB



PINPOINT TEST M: THE DEFROST SYSTEM WILL NOT SHUT OFF AUTOMATICALLY - FUSION, MILAN

-------------------------------------------------
M1 CHECK CIRCUIT CLS38 (VT/WH) FOR SHORT TO VOLTAGE


- Disconnect: SJB C2280E.
- Disconnect: Rear Window Defrost Grid Power C402A.
- Ignition ON.
- Measure the voltage between rear window defrost grid power C402A-1, circuit CLS38 (VT/WH), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
REPAIR the circuit. TEST the system for normal operation.

No
INSTALL a new SJB. REFER to Body Control Systems for the removal and installation procedure. TEST the system for normal operation.

-------------------------------------------------