Started on My LS1/5.7 swap, into My 01 XJ

[JeremyB]

Originally Posted by jamiemac

Yes, I'm pretty sure the stock cruise will work on a cable throttle system, But You have to use the Jeep PCM as a mule to operate it, using the Jeep vehicle speed sensor. A lot of extra wiring, that I'm now thinking of eliminating.

Not sure on the 4l60 but with my 4l80 it has a speed sensor in the trans. I simply tied the GM PCM VSS output in to my Jeep PCM VSS input. I was lucky, my speedo is 1 mph off at 60, but you can have that re-calibrated with a tune. As for the throttle by wire you will have to use an aftermarket Cruse or change to a cable TB. I will have my cable TB up for sale or trade as soon as my L92 heads get here.

[jamiemac]

Originally Posted by JeremyB

Not sure on the 4l60 but with my 4l80 it has a speed sensor in the trans. I simply tied the GM PCM VSS output in to my Jeep PCM VSS input. I was lucky, my speedo is 1 mph off at 60, but you can have that re-calibrated with a tune. As for the throttle by wire you will have to use an aftermarket Cruse or change to a cable TB. I will have my cable TB up for sale or trade as soon as my L92 heads get here.

The 4L60e has the VSS in the tail shaft housing, which is removed for the 4WD conversion. The Advance Adapters Tcase adapter has the VSS in the adapter ring though. So this will allow for using that VSS to control PCM functions, and shift gears at the right time, when in 4low. However, the speedometer would be off in 4low, if using the VSS in frt of the Tcase, so I'll be using the Jeep's oem VSS for a speedometer output. Auto Meter said it will work just fine. Long way to go, before I get to that point though.

[Hoooper]

Originally Posted by JeremyB

As for the throttle by wire you will have to use an aftermarket Cruse or change to a cable TB. I will have my cable TB up for sale or trade as soon as my L92 heads get here.

my understanding from a lot of reading is that drive by wire cruise control is much easier to set up. All you need is the correct speed signal to the PCM and a couple wires that you should be able to easily find from your Jeep cruise control wiring (cruise control on/off, cruise control set, and brake lamp)

http://www.lt1swap.com/dbw.htm

[cjlagos]

I'd be surprised if the Factory Jeep PCM will drive the factory vacuum cruise module after all the engine wiring/sensors removed.

GM Gen III PCMs are straight forward to integrate cruise with drive-by-wire controls. They just need the cruise signals and clutch/brake switches. I believe that Gen IV and later will require BCM and be more difficult to integrate.

The factory Jeep cruise control switches on the steering wheel is just a single wire to the PCM which uses a resistance ladder to signal which button is being pressed. So, gotta separate seperate the signal into separate circuits to feed into the GM PCM.

I made a couple quick You Tube videos:

https://www.youtube.com/watch?v=twuXNTN9xzo

https://www.youtube.com/watch?v=MrUkMRB3ems

[Hoooper]

I dont know if the harness from my 96 is different from the 01 control, but the control buttons are certainly different. On the 96 the PCM only seems to receive a cruise power input and signal input which would suggest maybe its the same. I can tell you for sure that the Jeep PCM will not let you use cruise if the NSS is disconnected, so unless you feed it a fake signal for NSS and probably other sensors the Jeep PCM wont help you. Im not completely sure I buy the pinout for the 96 though unless there is another control module in between. The steering wheel definitely has three distinct buttons for on/off, accel/resume, and set/coast unlike the 01 you show which only looks like two distinct buttons

[cjlagos]

Originally Posted by Hoooper

I dont know if the harness from my 96 is different from the 01 control, but the control buttons are certainly different. On the 96 the PCM only seems to receive a cruise power input and signal input which would suggest maybe its the same. I can tell you for sure that the Jeep PCM will not let you use cruise if the NSS is disconnected, so unless you feed it a fake signal for NSS and probably other sensors the Jeep PCM wont help you

I haven't looked at the 96 schematics but that's probably a ground into the switch, not power. The switch then grounds the signal wire into the PCM and varies the resistance to signal which button is being pressed.

Hth.

[Hoooper]

Originally Posted by cjlagos

I haven't looked at the 96 schematics but that's probably a ground into the switch, not power. The switch then grounds the signal wire into the PCM and varies the resistance to signal which button is being pressed.

Hth.

the pinout says "cruise control power supply". Thats all I have to go by. The signal is a different pin.

[jamiemac]

The cruise control info is great info. Just more reason to use a Rostra, or get one of the Audiovox CC100 units that's still left out there. They discontinued that model, but it's still available the last time I checked.

Still too cold for Me to work on the XJ, today. I did however, take a picture of some of the parts that have been trickling in over time.

Here is My new Sanden 508 AC pump, to go on the Holley accessory brackets. The TCI tranny rebuild kit, with a shift kit included. Some incandescent dash indicator lights, for turn signals, MIL, Oil pressure, etc. A Novak shift cable kit, for the NVG or NP 231, and a B&M Quicksilver shifter for the 4L60e tranny. Oh, and the little blue thing is a battery cable terminal crimper. I needed one of those.

[jamiemac]

Going over some wiring diagrams, and have determined that the AC system will operate without the PCM. You just have to use ouput power from the AC request switch to send power to the AC clutch relay, while going thru the low & high pressure switches. Power from the high pressure switch will also be sent to either a fan relay, or to an input for a fan controller, which is what I;ll be using.

Thanks to John D for his insight that got Me to thinking, otherwise I's still be messing with the Jeep PCM, and that was slowing Me down.

[Hoooper]

you could alternatively just rewire your A/C request signal to the LS1 PCM and run the A/C controls off the LS1 PCM couldnt you? Im opting to keep the Jeep PCM so I can keep all my stock gauges and what not but the LS1 PCM is capable of handling all of those functions for the most part anyway if it werent for the CCD bus. Since you sound like you are going to replace the gauges it maybe makes sense for you to dump the Jeep PCM. If you werent it seems like it would make sense to keep the A/C on the Jeep PCM.

[jamiemac]

Yep, the LS1 PCM will most likely do a fine job of running the A/C, but having to use both PCMs and make a spot for both, just wasn't sitting right in My mind. There's definitely more than one way to skin this cat, though, and I'm the farthest thing from an expert. I'm still in the process of stripping down the Jeep harness to the bare essentials. As a matter of fact, back to work I go.

[Hoooper]

Originally Posted by jamiemac

Yep, the LS1 PCM will most likely do a fine job of running the A/C, but having to use both PCMs and make a spot for both, just wasn't sitting right in My mind. There's definitely more than one way to skin this cat, though, and I'm the farthest thing from an expert. I'm still in the process of stripping down the Jeep harness to the bare essentials. As a matter of fact, back to work I go.

yeah, like I said if youre planning to run aftermarket gauges the Jeep PCM has a lot less value in it. I think the same goes for if you had a pre-96 cherokee (before CCD was running most/all of the gauges). Have you considered whether your interior items aside from HVAC will work? I have seen some postings that suggest a bunch of their interior lights and such dont work after removing the Jeep PCM. Dont know for sure if thats the case though

[John D]

The only thing I noticed that doesn't work after the Jeep PCM delete is the rear defogger and I'm not even sure that worked before.

[jamiemac]

I'll look over the defogger diagrams, tonight. I think it's controlled by the BCM.

[Hoooper]

if you look over the pinouts for the 96 diagram the only things with any effect on the interior are the CCD bus and the A/C controls. Maybe people who reported losing interior functions also pulled the BCM not knowing thats what it was? The 2000-2001 PCMs appear to maybe be different but I would be surprised if Jeep decided to just randomly throw some extra controls on the PCM when they were already handled by the BCM which was still there.