Hacking a Renix Jeep Cruise Control

[Raccoonjoe]

OK folks, here's the scoop:

I've been tossing around the idea of modifying the factory cruise so that it becomes a throttle lock, as opposed to a speed lock. In order to do this, I'm going to need to muck around in the wiring. Attached are 2 wiring diagrams, straight from the FSM, hot from the photocopier at the local Jeep dealer....

According to the diagrams, the only wire I should need to disconnect would be the one from the VSS, correct?? This *should* allow me to set the cruise at my desired speed (since I don't have SGII to tattle on TPS readings), and leave it there until I touch the brake pedal. The brakes should still disable the cruise.

Does this make any sense to you folks, or am I just blowing sunshine up my proverbial skirt??

**edit -- follow the links to see the photos
http://i164.photobucket.com/albums/u...eepwiring1.jpg
http://i164.photobucket.com/albums/u...eepwiring2.jpg

[Raccoonjoe]

Seems I've overlooked the previous thread (last week sometime) about the Saturn CC hack. Looks like I need to join in on that discussion.....

[Raccoonjoe]

I sent a PM to rh77, hopefully he (or one of the other mods) can take care of the title issue for us.

As I read through the Saturn thread, then returned to study my diagrams some more....They are not as similar as I was initially hoping. I'm sure there's somewhere out there who is better at the wiring logic than me....the more ideas the merrier

[GasSavers_Red]

On the TJ the CC module is built in to the ECU so the wiring is a bit different. do you have the schematic for the CC servo plunger RJ? From my read of cfg83's post, the goal is to lock out the ECU from futzing with the plunger with effectively "locks" the throttle. So you want to splice into the leads the power the servo motor. I'll post up my schematic of it when I get home.

I don't think cutting the VSS signal would be a good idea since the VSS is used to let the computer know that the Jeep is moving faster than 35 mph and its safe to engage the CC. Else you might be able to engage the CC at any speed or not at all.

[GasSavers_Red]

I found a online copy of my FSM, images attached. My guess is that you want to cut into V36 and V35 to prevent the ECU from activating the servo once the CC has been engaged.

[Raccoonjoe]

That's a good point you have, Red. I hadn't thought about the VSS enabling the CCM.

The difference between your CC and mine is rather significant. You've got the cruise built into your ECU, where the AMC/Renix engineers put mine in a totally separate unit.

[GasSavers_Red]

Yep, but knowing DCX, while the guts might get moved around, the circuit is the same. So there might be something close on yours.