Normal Operation

WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

DTC B1318 (Battery Voltage Low) - sets in the Trailer Brake Control (TBC) module when the TBC module detects that battery voltage has dropped below 9 volts on the voltage supply circuit while not braking.

This pinpoint test is intended to diagnose the following:

Wiring, terminals or connectors
High circuit resistance
TBC module