E 450 V8-5.4L (2009)
REPAIR circuit CBP44 (VT) for a short to voltage. TEST the system for normal operation.
No
GO to X12.
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X12 CHECK FOR CORRECT SJB OPERATION
-
Disconnect all the SJB connectors.
-
Check for:
-
corrosion
-
damaged pins
-
pushed-out pins
-
Connect all the SJB connectors and make sure they seat correctly.
-
Operate the system and verify the concern is still present.
-
Is the concern still present?
Yes
INSTALL a new SJB. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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Pinpoint Test Y: The Trailer Electric Brakes Are Inoperative/Always Applied
Trailer Lamps
Pinpoint Tests
Pinpoint Test Y: The Trailer Electric Brakes Are Inoperative/Always Applied
Refer to Wiring Diagram Set 95, Trailer/Camper Adapter for schematic and connector information. See: Diagrams/Electrical Diagrams/Diagrams By
Number
Normal Operation
The trailer electric brake controller is provided voltage at all times by the Battery Junction Box (BJB) fuse 18 (30A) through circuit SBB18 (YE/RD).
Ground for the trailer electric brake controller is provided through circuit GD116 (BK/VT). The trailer electric brake controller receives voltage from
the stoplamp switch through circuit CCB08 (VT/WH) when the brake pedal is applied. When a brake application is detected from the stoplamp switch,
the trailer electric brake controller sends voltage to the trailer tow connector through circuit CAT19 (BU).
This pinpoint test is intended to diagnose the following:
-
Fuse
-
Wiring, terminals or connectors
-
Trailer tow connector
-
Trailer electric brake controller
-
Trailer
PINPOINT TEST Y: THE TRAILER ELECTRIC BRAKES ARE INOPERATIVE/ALWAYS APPLIED
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the
connector.
NOTE: Before beginning diagnostics, visually inspect the trailer tow connector for signs of corrosion or damage. Repair or install a new trailer tow
connector as required.
