RJN8; Your 392 Linde LPG truck's problems are happening because of the following reasons. Cause of T238: Brake sw connections have been reversed; Brake sw (1S1) - located at brake release valve. This valve can be found when you remove the floor mat, unfasten the floor plate and raise it enough to hang it on the steering wheel spinner. With the floor board raised look down on left side (ref. - operator seated) just below were you would first step up into the cab and you will be seeing the brake release valve and two switches mounted on it. The top sw is (1S1) and the lower sw is (1S2). A second cause for T238 could be a bad (1S1) sw, while a third reason could be a bad (1S2) sw. Your truck could have a forth cause which could be a bad connection sw to controller (N1) pin 58 - orange wire which is located just behind the elec. compartment cover at operator cab's rear. A fifth cause may be a bad connection brake sw (1S2) to controller (N1) pin 59 green/white tracer wire. The T239 is occuring because the controller (N1) inputs for the seat sw (S4) pins 33 wire black/brown and pin 38 wire brown/yellow are the same. The cause for the L239 fault is the NO/NC seat sw (S4) may have a bad connect at the plug socket (X4) pin 1 black/brown wire, pin 2 Brown - BAT - and pin 3 brown/yellow and/or the controller (N1) pin 33 and pin 38.