2007 International 9400 cruise/jakes issue (Cummins ISX)

[lciambotti]

OK, so the issue is, the cruise has been acting funny, reving up and down when it feels like it. I tell the guys to idle the trucks about 900 rpms when sleeping. The jakes have been working off and on, then quit a week ago. My driver said the cruise didn't seem to work while it rained, but last night it was chilly and damp so he shut the truck off. Started it this morning, sunny and the cruise was acting up (reving up to 2000rpm's then come back down), but the jakes started working. I have no idea where to start. Any ideas? Thanks!

 

[Ontario Outlaw]

Isolate where the problem is. Check for greenies at the ECM plug, the bulkhead plug, clean and check the jake plugin on the head.

Try different switches in the dash to see if that helps. Check TPS and all the pedal switches, clutch brake fun pedal

On mine I chased these issues for a long time and ended up replacing the main engine harness to fix it

Yours playing up in wet weather leads me to think bad connection or broken wire

 

[r3gulator3]

Isolate where the problem is. Check for greenies at the ECM plug, the bulkhead plug, clean and check the jake plugin on the head.

Try different switches in the dash to see if that helps. Check TPS and all the pedal switches, clutch brake fun pedal

On mine I chased these issues for a long time and ended up replacing the main engine harness to fix it

Yours playing up in wet weather leads me to think bad connection or broken wire

I approve this message.

 

[Rigjockey]

OK, so the issue is, the cruise has been acting funny, reving up and down when it feels like it. I tell the guys to idle the trucks about 900 rpms when sleeping. The jakes have been working off and on, then quit a week ago. My driver said the cruise didn't seem to work while it rained, but last night it was chilly and damp so he shut the truck off. Started it this morning, sunny and the cruise was acting up (reving up to 2000rpm's then come back down), but the jakes started working. I have no idea where to start. Any ideas? Thanks!

I had one of those trucks. I had issues with the cruise and the jakes. it turned out, it was a spring that was not returning the clutch pedal back to the sensor.
This may or not be your issue but something to look at.

 

[Silverwolf]

Go to Rawze.com, ask Rawze about it. He IS the expert on the ISX. Cummins engineers and mechanics ask him for advice it they cant figure it out. He invented the EGR tune up saving thousands of trucks. Took him 30minutes to respond to my post. And he was 100% right, first try. The guy is amazing, and his maintenance videos on youtube are fantastic and free.