2006 Ford F 250SD 5.8L engine. No turn signals, break lights, or flashers. "TBC Fault" when pressing the brake pedal and no trailer connected. All fuses under the dash and under the hood are OK. Wiring and trailer plugs do not seem to show any shorts. What's up Doc? Thanks.
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Re: 2006 Ford F 250SD 5.8L engine. No turn signals, break...
Thanks for using FixYa. Looks like you are having a relay problem. I suggest that you go ahead and try to replace the relays for the turn signal and break lights. If this doesn't help, you'd probably want to get a multimeter to check for any shorts. Try using a fuse with lower amperage for the turn signal and break lights. See if they blow up. If they do, you've just isolated that you have a short in the wiring system.
I hope this helps. Thanks and good day. HotRatchet
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check the brake lamp/turn signal bulbs. sometimes in a dual filament bulb the filament will break and lay over on to the other, so when the turn signal is on and the brakes are applied, it just powers the circuit by-passing the flasher
The STOP LP 25-amp fuse in the underhood fuse block supplies battery positive voltage to the normally open stop lamp switch. When the driver presses the brake pedal, the switch contacts close and battery positive voltage is supplied to both the STOP 15-amp fuse and the center high mounted stop lamp (CHMSL) 10-amp fuse in the instrument panel (I/P) fuse block, and to the turn signal/hazard module. The turn signal/hazard module then supplies voltage to both of the trailer rear turn/stop lamp supply voltage circuits. The voltage from the CHMSL 10-amp fuse is to the CHMSL and the trailer jumper harness. The voltage from the STOP 15-amp fuse is to the stop lamps, throttle actuator control (TAC) module, and the cruise control.
I think The turn signal/hazard module has something to do with the lights flashing .From looking at a wiring diagram B+ voltage from the STOP LP fuse 25amp in the under hood fuse box supply's the brake light switch , from there it feeds B+ to VEH STOP fuse 15amp and VEH CHMSL fuse 10amp an to stop lamp switch signal to the turn signal flasher module which is suppose to control the trailer stop lights . Do you have a connection for a trailer hook up ?
Remove both LT an RT TRLR fuse's both 10 amp from the I/P fuse block an see if the problem goes away .
Do you tow a trailer ? Check the trailer connector for corrosion !
Lighting control module ? ?????? Hazard / flasher module ! Now ( there''s not even an electrical signal where the fuse plugs into the interior fuse panel.) What FUSE ??????
The STOP LP 25 A fuse in the underhood fuse block supplies battery positive voltage to the normally open stop lamp switch. When the driver presses the brake pedal, the switch contacts close and battery positive voltage is supplied to both the STOP 15 A fuse and the CHMSL 10 A fuse in the I/P fuse block, and to the turn signal/hazard module. The turn signal/hazard module then supplies voltage to both of the trailer rear turn/stop lamp supply voltage circuits. The voltage from the CHMSL 10 A fuse is to the center high mounted stop lamp (CHMSL) and the trailer jumper harness. The voltage from the STOP 15 A fuse is to the stop lamps, throttle actuator control (TAC) module, and the cruise control.
The backup lamp request signal is sent from the powertrain control module (PCM) to the body control module (BCM) on the Class 2 message system. This signal is based on the park neutral position (PNP) switch signal. The BCM supplies voltage on the backup lamp supply voltage circuit to the backup lamps and to the automatic day/night mirror. Voltage for the courtesy lamp supply voltage circuit and backup lamp supply voltage circuit is from the TBC B fuse in the instrument panel fuse block directly through the BCM to these circuits. A short to ground on either of these circuits will open the fuse. The backup lamps are grounded at G401.
For trailer wiring, a separate backup lamp circuit is connected through the underhood fuse block from the TRLR B/U 10 A fuse to the trailer wiring harness.
Turn Signal/Hazard Lamps
The IGN E 10 A fuse in the underhood fuse block supplies battery positive voltage to the turn signal/hazard switch assembly. The FLASH 25 A fuse in the I/P fuse block supplies battery positive voltage to the turn signal/flasher module and ground is supplied at G200. When the turn signal switch is placed in either the left or right position, a voltage signal is completed from the turn signal switch to the turn sign/flasher module. When the hazard flasher switch is activated, a ground signal is completed from the turn signal/hazard switch to the turn sign/flasher module. The turn sign/flasher module then sends an on-off voltage signal through the LT TRLR, RT TRLR, LT TURN or RT TURN 10 A fuses in the I/P fuse block to the appropriate turn signal or to all 4 fuses for hazard operation. The instrument panel cluster (IPC) indicators receive voltage from the LT TURN and RT TURN fuses as well as the DDM/PDM for the mirror turn signals. The DDM/PDM has no function or control of the mirror turn signals other that a pass through connection for the circuits. The audio chime is also activated when the turn signals are on. When the hazard switch is pressed, all turn signal lamps will flash including both IPC turn indicators. The front turn signals are grounded at G100. The rear turn signals are grounded at G401. The Mirror turn signals are grounded by the DDM/PDM.
Do you know how to do automotive electrical circuit testing with a test light or volt meter ? How to read an use a wiring diagram to pin point testing points . ( connectors , fuse locations etc... ) How to use a power flow chart ? Here is a site for just such info .
TBC means Trailer Brake Controller fault.Check for moisture/water in the trailer plug connector at the back of your truck. Water/moisture will cause TBC error codes. Look for moisture at all connections to the plug and inside the plug.Trailer brake controller that is built into your dash. If you are hooked up to a trailer it could mean you are losing your connection or ground to the trailer. If you are not connected to a trailer it means there is a problem with your brake controller possibly a short in the wiring caising the fault code.-----It means either A) you have a bad ground on your trailer. Or B) your cable on your trailer is too short and causing it to pull out of the plug or C) you have a short in the factory trailer harness wiring or the plug is gunked up.---------get this possibilities checked.It will help.Thanks.Helpmech.
If the Brake light filaments in the globes are OK then you could have a bad connection some where in the brake light circuit from where the trailer connector cable is tapped into the vehicle wiring loom.
Start by disconnecting the trailer connector and checking on the vehicle socket for an indication that voltage is present by using a multimeter or test lamp while the brake pedal is pressed. If not OK, then the fault is either where the brake light wire is screwed into the socket or the connection in the vehicle wiring loom.
If OK then reconnect trailer plug and after removing cover, check the trailer plug where the brake light wire is screwed into it. If OK, then check where wire is connected at trailer lamps. If not OK, then there is a broken wire in the trailer cable.
That is your trailer brake controller that is built into your dash. If you are hooked up to a trailer it could mean you are losing your connection or ground to the trailer. If you are not connected to a trailer it means there is a problem with your brake controller possibly a short in the wiring caising the fault code.