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Smiling lemon · 12-16-2022, **(Subject: Jake wiring )**

I believe the reason my jake brake has not been working is that my cab controller is dying, I tried to get it updated awhile back and the tech said he had to try it 5 times to get it to take the update.
Cm2530 x101
2016 W900
My plan is to bypass the cab controller and goto the ecm for wiring. I have the smart wheel and it looks like ecm activation is short signal to ground. My plan is to take a relay and wire signal from ecm to a ground and when I hit switch on the wheel relay will close to ground activating the Jake. Before I started doing something that could damage the ecm I wanted to confirm that is how it works. My other thought was to just bypass that all together and insite says the solenoids need to be supplied with 12VDC, so I would just put a switch that would activate the Jake solenoid directly. Just have to remember to open them back before throttling up again but still think it'll be better to have Jakes back.

Rawze · 12-16-2022, **(Subject: Jake wiring )**

Its one thing to mess around with a non-critical system like the AC or some other things, but critical internal engine operations, etc... I would not recommend it.

The engine is firing/fuelling cylinders + the jake solenoids still active very well could make a piston strike a valve. = expensive overhaul.

Even at idle, the engine is supplying fuel to the cylinders. I have seen people loose an engine over just activating the by hand on a fresh inframe before when everything was tight and new due to this. Above idle fueling and this gets dangerous real fast.

Much safer and more reliable to just replace the cab controller (or whatever is actually wrong) if that is what it needs.

Smiling lemon · 12-16-2022, **(Subject: Jake wiring )**

(12-16-2022 )Rawze Wrote: Mush safer and more reliable to just replace the cab controller (or whatever is actually wrong) if that is what it needs.

Every time this seems to be an option something happens and I am unable to go that route, been driving around for years like this and the diagnostics for this show up with indefinite cost.

Smiling lemon · 12-20-2022, **(Subject: Jake wiring )**

For anybody who also needs it here is a pdf of cab controller pin out and smart wheel module

{Files removed by Rawze}. This is not a file/software trading site!.

Rawze · 12-21-2022, **(Subject: Jake wiring )**

(12-20-2022 )Smiling lemon Wrote: For anybody who also needs it here is a pdf of cab controller pin out and smart wheel module
...

If you want to post copies of diagrams and other official files publicly, then find a valid link to those files that binds directly back to the manufacturer, or a source that they approve of, to prevent copyright claims.

That or people can PM (private message) you with requests for whatever info you do have.

Thanks.

Smiling lemon · 12-21-2022, **(Subject: Jake wiring )**

Update, grounding out either wires activates jake symbol on dashboard, cecu does not recognize input from smart wheel module but everything works post cecu.

Is the Jake symbol on the dash commanded by cecu signal or would it just be wire grounding? Maybe another wiring diagram will answer this. The only think not working on the cecu is Jake, does anybody know somebody willing to do component board repairs?

Gill Oruga · 01-01-2023, **(Subject: Jake wiring )**

(12-21-2022 )Smiling lemon Wrote: Update, grounding out either wires activates jake symbol on dashboard, cecu does not recognize input from smart wheel module but everything works post cecu.

Is the Jake symbol on the dash commanded by cecu signal or would it just be wire grounding? Maybe another wiring diagram will answer this. The only think not working on the cecu is Jake, does anybody know somebody willing to do component board repairs?

The CECU gets the on signal from the wheel and in turn, it switches your light on in the dashboard.

Did you get the engine brake working?

AFAIK, you can no longer hardwire Ebrake on/off switches on these CM2350's. Only the hi/lo selectors.

Did the OEM plug come with wires on pins 68 and 86?
I highly doubt it since the signal will be digital from the CECU.

You could try putting wires on those holes and use a switch on those pins and turn off the engine brake selectors under the SAE J1939 option in INSITE.

Once you do that you can disable the output for engine brakes on the CECU with ESA and you should have a working analog switched brake again.

In theory.

An update might also work on your CECU.

Smiling lemon · 01-02-2023, **(Subject: Jake wiring )**

(01-01-2023 )Gill Oruga Wrote:
(12-21-2022 )Smiling lemon Wrote: Update, grounding out either wires activates jake symbol on dashboard, cecu does not recognize input from smart wheel module but everything works post cecu.

Is the Jake symbol on the dash commanded by cecu signal or would it just be wire grounding? Maybe another wiring diagram will answer this. The only think not working on the cecu is Jake, does anybody know somebody willing to do component board repairs?

The CECU gets the on signal from the wheel and in turn, it switches your light on in the dashboard.

Did you get the engine brake working?

AFAIK, you can no longer hardwire Ebrake on/off switches on these CM2350's. Only the hi/lo selectors.

Did the OEM plug come with wires on pins 68 and 86?
I highly doubt it since the signal will be digital from the CECU.

You could try putting wires on those holes and use a switch on those pins and turn off the engine brake selectors under the SAE J1939 option in INSITE.

Once you do that you can disable the output for engine brakes on the CECU with ESA and you should have a working analog switched brake again.

In theory.

An update might also work on your CECU.

The ECU wants to see those two wires grounded out for level three jake. I spliced in wires up at the cecu that go to a switch that is grounded out and when I flick the switch Jake's and the dash light up. The smartwheel module puts out a voltage signal to the cecu not a digital and I tested to see that the cecu receives the signal on the pins but it doesn't respond. The only jake motion I have gotten was grounding out pins 11/12 from the cecu and I get jake light and jake solenoid activation. At this point my guess is that something is wrong on the board of the cecu, a relay or something went out and it no longer grounds those pins. I haven't been able to find a board schematic or someone willing to diagnose it

Rawze · 01-02-2023, **(Subject: Jake wiring )**

(01-02-2023 )Smiling lemon Wrote: ...
The ECU wants to see those two wires grounded out for level three jake. I spliced in wires up at the cecu that go to a switch that is grounded out and when I flick the switch Jake's and the dash light up. The smartwheel module puts out a voltage signal to the cecu not a digital and I tested to see that the cecu receives the signal on the pins but it doesn't respond. The only jake motion I have gotten was grounding out pins 11/12 from the cecu and I get jake light and jake solenoid activation. At this point my guess is that something is wrong on the board of the cecu, a relay or something went out and it no longer grounds those pins. I haven't been able to find a board schematic or someone willing to diagnose it

Just some related info to consider ...

Many of the buttons on my prostar (other brands of trucks may use this strategy too?) actually work by sending a specific voltage instead of an on/off. for the cruise and resume, and the engine brake and other buttons, it will send 3.3-vlots for one button, and 2.7volts for a different one, and 4.5 volts for a different one yet. - These are not digital signals.. but a steady voltage, and the cab controller reads the voltage and determines if it is in range or not.. and then acts accordingly.

This works great .. until the fuses in the fuse panel get tarnished/discolored a tiny bit over time. Then suddenly the cruise button does not work.. or the engine brake buttons stop responding, etc.. because the voltage they send has dropped a tiny bit and the cab controller rejects the signal.

SO.... HAVE YOU cleaned all the connectors to the device not working well, and replaced all of the fuses in the fuse blocks with new ones before assuming that the cecu itself is the problem?. That is one of the things that has gotten a lot of people on these newer trucks, and is far more common of an issue that most would think. Fuses are all perfectly good... check out just fine.. but replace them, and things start working again, ghosts problems in the dash and/or button issues will clear up. -= Terrible design if you ask me, but who am I.

I have an article on just this, located here...
ref: http://rawze.com/forums/showthread.php?t...1#pid12861

also.. there are many reasons that the engine brake will not engauge. a person needs the CECU software to see if the actual signals are being read into, and sent out of the device properly, and without that it is anyone's guess. Same thing for the engine side. they are 2 seperate systems, each with their own requirements.