Pinpoint Test J: The STOPLAMPS Are On Continuously

WARNING: This page is about a different car, the 2006 Ford F550 Super Duty, 2006 Ford F450 Super Duty, and 2006 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

J1 CHECK THE STOPLAMP SWITCH
- Disconnect: Stoplamp Switch C278.
- Do the stoplamps continue to illuminate?
Yes : If equipped with a trailer brake module, GO to J2.

If not equipped with a trailer brake module, GO to J3.

No : INSTALL a new stoplamp switch. REFER to STOPLAMP SWITCH . TEST the system for normal operation.
J2 CHECK THE TRAILER BRAKE MODULE
- Disconnect: Trailer Brake Module C2142a.
- Do the stoplamps continue to illuminate?
Yes : GO to J3.

No : GO to J5.
J3 CHECK CIRCUIT 511 (LG) FOR A SHORT TO VOLTAGE
- Disconnect: Multifunction Switch C202a.
- Does the high mounted stoplamp continue to illuminate?
Yes : REPAIR the circuit. TEST the system for normal operation.

No : GO to J4.
J4 CHECK THE MULTIFUNCTION SWITCH
- Connect: Multifunction Switch C202a.
- Disconnect: Multifunction Switch C202b.
- Do the rear stoplamps continue to illuminate?
Yes : REPAIR circuit 5 (OG/LB) (LH rear lamp) or circuit 9 (LG/OG) (RH rear lamp) as necessary. TEST the system for normal operation.

No : INSTALL a new multifunction switch. REFER to STEERING COLUMN SWITCHES . TEST the system for normal operation.
J5 CHECK FOR TRAILER BRAKE MODULE OPERATION
- Disconnect all the trailer brake module connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all the trailer brake module 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 trailer brake module. REFER to AUXILIARY BRAKE SYSTEM . 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.