Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Pinpoint Test F : U3003:16: Notes
Refer to Trailer/Camper Adapter for schematic and connector information
Normal Operations and Fault Conditions
The TBM requires an operating voltage between 9 and 16 volts. The TBM receives this voltage from the BJB. The TBM has a single ground circuit. Excessive resistance or an open in one or more of these circuits, a discharged battery or a inoperative charging system results in the TBM setting a DTC. If the voltage drops below 8 volts the TBM disables the trailer brake output and shuts down.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| U3003:16 | Battery Voltage: Circuit Voltage Below Threshold | This DTC sets in continuous memory and on-demand if the voltage supplied to the TBM is less than 9 volts for longer than 5 minutes while not braking. |
Possible Sources
- Fuses
- Wiring, terminals or connectors
- Charging system concern
- Battery
- TBM
Visual Inspection and Diagnostic Pre-checks
- Make sure the vehicle battery terminals and cables are free of any corrosion and other contaminants.
- Make sure the vehicle battery terminals are tightened to their correct torque specifications.
- Make sure BJB fuse 49 (30A) is OK.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.