[Corey]

Look carefully in that chassis electrical compartment below the driver. It’s easy to overlook a popped breaker because it’s just a little round pin sticking out of the breaker further than any others. If you find it, push it back in and replace the switch on the dash.

This from my experience, be vintage sensitive.

[Archived]

I did check the breakers, none were popped. I’ll double-check tomorrow. There should be Jacobsbrake control unit somewhere but I have not found it yet.

Gerald

[Michael]

Gerald,

My jake has dropped out a few times over the years and I have never found any answers. One thing I have done that caused it to work again was to lift the accelerator with my foot. Some one had suggested that the switch there was showing I still had my foot on the gas. Another thing was to turn off the bus and restart the engine. That has always worked. It has only happened a handful of times and of course it has never duplicated with an expert around.

Davy

[Steve]

Davy,

thanks for the tip. I’ll try it tomorrow.

It is surprising how little engine braking there is without the jake.

Gerald

[Chris]

I haven’t had a Jake on a Series 60, but on my 8V92 in the rear electric box there were two posts that when hot would actuate the solenoids for the Jake.

At idle I would use a jumper from the 12 Volt post to one of the Jake posts. (I think on that coach they were posts #1 and #2) With power to the post I could hear the Jake engage and the engine lug down. I would do that to each of the posts to verify the Jake was working, at least at the engine. If I powered both Jake posts I could stall the engine.

I suspect but do not know for sure there is a similar set up on Series 60 coaches. By doing the test which only takes a couple of minutes you isolate where to look for the problem, either at the key pad which controls the Jake or at the rear.

[Archived]

A couple of things to loook at. First check the gas pedal, making sure it comes all thje way back. Be sure the floor mat has not snuck up under it preventing it from returning all the way. Second try turning the cruise off, sometimes the cruise will disable the rake.

Good Luck.

Mikee

[Larry]

Jake was back all day today. Of course, I was traveling in the central california flatlands. So did not need him really. We’ll see if he sticks around on the next mountain pass.

As you guys pointed out, the cause of my problem was probably the throttle position sensor (gas pedal) not fully going back to idle. This prevents the jake from coming on. The DDEC simply figured I was still on the throttle, no jake for you. Thus no codes or lights.

Based on your feedback, I made sure the gas pedal mechanism went through its full range and did the recalibration (3 x fully depress gas pedal with the ignition on). Good so far.

You guys are great! Thanks for everyone’s help.

Gerald

[Greg]

Happened to me too. Jake would stop working and I would have to shut the coach off and then turn it back on to make it work again; it continued to fail every five hours or so. I made it to Marathon a couple days later and they replaced the Throttle position sensor. All is well since.

It’s disconcerting to say the least. I lost mine on CA 299 west of Redding heading to the coast.

[Peter]

Some explanation and additional discussion in –

Loss of Jake, and other ECM related problems

http://prevostcommunity.com/forum/threaddetails.asp?Category=Chassis&ThreadID=5284

Ed Roelle

810-516-9888