SAM chassis module failure - Great!

Actually, most new trucks have this, not just freightliner. Werner claims all trucks after 07 have it, so im going to take that to mean that "PACCAR and freightliner" have it. heh.

There's a reason for it. Less wires. Most wires are now shared by multiple components. As the truck ages, there's less wires to break, and theres a significant reduction in manufacturing costs because of it.

I honestly dont get it. How the hell is it cheaper? There's been lots and lots of SAM software recalls (my truck has all of them), and lots of problems with the system. This means...excessive repairs covered by warranty.

BTW, I found out werner purchases an extended warranty on their trucks and apparently sells them before the warranty runs out. Hahahaha.

 

I understand less wires is cheaper to make but when the truck is out of warranty and the owner has to pay for repairs a $7 roll of wire on a repair bill is better than a $2000 computer.
Like any system it will get better once it has been furthur developed I suppose.

 

Just a thought on electronics..... when you buy a new computer, etc somewhere on the packaging/ literature you will find Do not expose to dust, moisture or excessive vibration. So where would you find more of each than the cab of an 18 wheeler???

 

The one on the truck is a little different, kittyfoot. personal electronics are not sealed from water (shouldnt NEED to be), things like DVD players use optical media, things like hard drives get damaged from excessive shocks or vibrations, etc...

The computer on the truck is totally water proofed, no moving or optical components. Same with a car.

FYI, i took apart a Bosch LH Jetronic fuel injection computer (ECM) once, to think about reverse engineering it. Obviously, all it is is a circuit board inside a metal box. The metal box is an RFI shield. Inside, the circuit board is dipped in what appears to be siliicone sealant, but is actually something else.

 

Great info.What does modular switch field master module operate?

 

The MSFM is the module where your hazard switch is (If I remember right). This is the module that sends switch info over the cabin CAN (Controller Area Network). Then you have the Central Gateway Module, which converts CAN signals into J-1939 signals that other modules can understand, like the engine ECM(s).

To simplify it a bit. When you set your cruise, the MSFM senses the switch signal and sends that info over the Cabin CAN to the Central Gateway Module. The CGM sends that info over the J-1939 data link to the engine. The engine ECM activates the cruise control.

It can be a complicated system, all vehicles are going this route. I do not believe that it "simplifies" wiring as they claim. Sure, many things under the dash are daisy chained together, which is simpler. But, the SAM's have more wiring. A lot more things are on separate circuits now so the SAM's can identify an issue and disable things without others. You may have a short in a marker light and only lose that light because they all have their own wire going to the SAM. That is 1 advantage, have a taillight short out and not lose all of them.

I think the simplification is on the OEM side. They can reduce the amount of wiring harness's they need to produce for different options. Added options are just a matter of plugging in a switch, gauge, etc and activating it in the proper module (with SericeLink for Freightliners). They are also heading toward IT style diagnostics. Dealers can plug the trucks in and Freightliner can remote diagnose.

I no longer work on Freightliners, but Pete and KW's have their own version of the same thing.

 

And still people think it is best to buy new trucks, instead of spending money on old paid for equipment.

 

What did you expect from the three pointed star?
Or, as I like to say in dealing with parts for their old diesels, Three points, three times the price. Stupidly over-complex just to be overly complex.

 

I'm having a problem my truck went in a safe mode I think cause the fan Motor heated up so how does it reset

 

That just scarie. My 07 kW has icu. Bad bad way to do thing.