Fulltext TSBs

Technical Service Bulletins

TSB
09-7-10
  • DIAGNOSTIC PROCEDURE FOR TRAILER TOW LIGHTS – SERVICE TIP
Publication Date: April 3, 2009

FORD:
2003-2006 F-Super Duty

This article supersedes TSB 06-6-1 to update the Service Procedures.

ISSUE:

Some 2003-2006 F-Super Duty vehicles used for towing may exhibit trailer lamps being inoperative or not working properly. This may be due to an open trailer tow fuse, a concern in the vehicle's wiring, a concern in the trailer's wiring, or the trailer not being wired properly for the vehicle.

ACTION:

Follow the Service Procedure steps to correct the condition.

SERVICE PROCEDURE

If the vehicle exhibits an open trailer tow fuse, refer to the following to determine if the open trailer tow fuse concern is caused by the vehicle or the trailer wiring. If the vehicle does not exhibit an open trailer tow fuse, follow normal diagnostics.

NOTE:FAULTS OR REPAIRS CAUSED BY TRAILER WIRING ARE NOT WARRANTABLE.

NOTE:VEHICLE WIRING MAY DIFFER FROM MODEL-TO-MODEL OR YEAR-TO-YEAR. ENSURE THE TRAILER IS WIRED CORRECTLY FOR THE VEHICLE.

NOTE:ELECTRIC POWER TO EACH TRAILER CIRCUIT IS SUPPLIED THROUGH A RELAY AND DEDICATED FUSE. (FIGURE 1)




Figure 1 – Article 09-7-10

4-PIN CONNECTOR 2003-2004 VEHICLES

  1. Check Fuses F2.6 and F2.38 in the central junction fuse box, located under the dash panel, left hand side.
    1. If the fuses are okay, do not continue with this procedure. Follow normal diagnostics to determine if the issue is in the vehicle or in thetrailer wiring.
    2. If a fuse is found open, proceed to Step 2.
  2. With the ignition key off, use a non-powered test light from battery positive terminal and test Pins 2, 3, and 4 for a short to ground. Pins 2, 3, or 4 must not have continuity to ground (no light). Pin 1 must have good continuity to ground (bright light – same as battery). (Figure 2)


    Figure 2 – Article 09-7-10

    1. If Pins 2, 3, and 4 pass the continuity test (no light), the concern is with the trailer wiring.
    2. If Pins 2, 3, and 4 fail the continuity test (light), locate and repair the concern in the vehicle's wiring.

7-PIN CONNECTOR 2003-2004 VEHICLES

  1. Check Fuses F2.6, F2.38, F2.39, and F2.115 in the central junction fuse box, located under the dash panel, left hand side.
    1. If the fuses are okay, do not continue with this procedure. Follow normal diagnostics to determine if the issue is in the vehicle or trailer wiring.
    2. If a fuse is found open, proceed to Step 2.
  2. With the ignition key off, use a non-powered test light from battery positive terminal and test Pins 1, 4, 5, 6, and 7 for a short to ground. Pins 1, 4, 5, 6, and 7 must not have continuity to ground (no light). Pin 2 must have good continuity to ground (bright light – same as battery). (Figure 3)


    Figure 3 – Article 09-7-10

    1. If Pins 1, 4, 5, 6, and 7 pass the continuity test (no light), the concern is with the trailer wiring.
    2. If Pins 1, 4, 5, 6, and 7 fail the continuity test (light), locate and repair the concern in the vehicle's wiring.

4-PIN CONNECTOR 2005-2006 VEHICLES

  1. Check Fuse F1.9 in the battery junction fuse box, located in the engine compartment, right rear side and Fuse F2.38 in the central junction fuse box, located under the dash panel, left hand side.
    1. If the fuses are okay, do not continue with this procedure. Follow normal diagnostics to determine if the issue is in the vehicle or in the trailer wiring.
    2. If a fuse is found open, proceed to Step 2.
  2. With the ignition key off, use a non-powered test light from battery positive terminal and test Pins 1, 2, and 3 for a short to ground. Pins 1, 2, and 3 must not have good continuity to ground (no light). Pin 4 must have good continuity to ground (bright light – same as battery). (Figure 4)


    Figure 4 – Article 09-7-10

    1. If Pins 1, 2, and 3 pass the continuity test (no light), the concern is with the trailer wiring.
    2. If Pins 1, 2, and 3 fail the continuity test (light), locate and repair the concern in the vehicle's wiring.

7-PIN CONNECTOR 2005-2006 VEHICLES

  1. Check Fuses F1.9 and F1.20 in the battery junction fuse box, located in the engine compartment, left rear side and Fuses F2.38 and F2.107 in central junction fuse box, under the dash panel, left hand side.
    1. If the fuses are okay, do not continue with this procedure. Follow normal diagnostics to determine if the issue is in the vehicle or in the trailer wiring.
    2. If a fuse is found open proceed to Step 2.
  2. With the ignition key off, remove Fuse F1.20 in the battery junction fuse box, located in the engine compartment, left rear side.
  3. With the ignition key off, use a non-powered test light from battery positive terminal and test Pins 1, 4, 5, 6, and 7 for a short to ground. Pins 1, 4, 5, 6, and 7 must not have continuity to ground (bright light – same as battery). (Figure 5)


    Figure 5 – Article 09-7-10

    1. If Pins 1, 4, 5, 6, and 7 pass the continuity test (no light), the concern is with the trailer wiring.
    2. If Pins 1, 4, 5, 6, and 7 fail the continuity test (light) locate and repair the concern in the vehicle's wiring.
  4. Replace fuse F1.20 after identifying repair.

WARRANTY STATUS:

Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
IMPORTANT: Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.

OPERATIONDESCRIPTIONTIME
MT090710Use SLTS Operations If Available; Claim Additional Diagnosis Or Labor Performed As Actual TimeActual Time

DEALER CODING

BASIC PART NO.CONDITION CODE
13A57642