F 550 2WD Super Duty V10-6.8L (2009)
manual slider switch fully to the left with a gain of 10, there should be greater than 10-12 volts supplied to pin 3 of the 7-pin trailer tow connector along
circuit CAT19 (BU).
Every 4 seconds the TBC module sends a voltage pulse along circuit CAT19 (BU) to pin-3 of the 7-pin trailer tow connector to determine whether or not
a trailer is connected.
The factory 7-pin trailer tow connector is attached with a bracket to the rear bumper of the vehicle or to the trailer hitch (if equipped). The 7-pin trailer
tow connector acts as a jumper connection between C4099 (female) and the trailer electrical connector (female).
-
C2806 Trailer Brakes Wiring Circuit Short to Voltage - If battery voltage is greater than 16 volts for 200 ms or more, the TBC module shuts off
trailer brake output and then shuts down.
-
C2807 Trailer Brakes Wiring Circuit Short to Ground - If battery voltage is less than 9 volts for 200 ms or more, the TBC module shuts off trailer
brake output and then shuts down.
This pinpoint test is intended to diagnose the following:
-
Wiring, terminals or connectors
-
TBC module
-
Customer trailer
PINPOINT TEST F: THE MESSAGE CENTER DISPLAYS WIRING FAULT ON TRAILER
NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.
NOTE: Make sure the trailer brakes are electric-magnet actuated drum type brakes before proceeding with this pinpoint test.
-------------------------------------------------
F1 CHECK THE MESSAGE IN THE MESSAGE CENTER
-
Verify that a trailer is not connected to the trailer tow connector.
-
Ignition OFF.
-
Allow the TBC module time to wake up and prove out.
-
Observe the message center.
-
Does the message center display WIRING FAULT ON TRAILER?
Yes
GO to F2.
No
SEND the trailer to an authorized camper/trailer repair center.
-------------------------------------------------
F2 CHECK THE TRAILER TOW CONNECTOR
-
Ignition OFF.
-
Disconnect: C4099 from the 7-Pin Trailer Tow Connector.
-
Check the connector C4099 and the 7-pin trailer tow connector for:
-
water intrusion.
-
corrosion.
-
pushed-out pins.
-
spread terminals.
-
Are the connectors OK?
Yes
GO to F3.
No
REPAIR the affected connector(s).
-------------------------------------------------
F3 CHECK THE TBC MODULE ON-DEMAND DTCs
-
Connect the scan tool.
