My 2012 Jayco Seneca Super C motorhome that sits on the Freightliner M2 chassis had an issue with the brake lights stuck in the on position, even when the vehicle was turned off. Turning the ignition on, didn’t solve the problem and the brake lights still stayed illuminated regardless. The vehicle is equipped with hydraulic brakes and an air brake for the parking brake. So I replaced the brake light switch that was located on the brake pedal itself, and that did not change or solve the problem. Next, I changed the parking brake switch and that did not solve the problem. Next, I replaced the chassis module, which is located on the frame rail of the driver side, and that also did not solve the problem. It turns out that the brake module that’s located in the dashboard behind the instrument panel failed and that’s what was causing the problem. So once that was replaced, everything returned to normal and the problem was solved. Hopefully, this will help somebody solve a similar issue. Brake Module P/N POL3201201
M2 many modules.
Common issue with all, most Freightliners are multiplex wiring with SAM. Signal Acquisition Module. no flasher. * The earlier FLC/FLD's used a timer built into dash warning display in top of dash, non repairable. Replace entire unit. * If marker lights start blinking with signals dimly, disconnect battery ground first, wait for a period of 20 minutes for module to reset, reconnect. Can be a come and go issue, as something sets it off.
Thanks for the info!