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Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go hereXJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.
I'm going to assume the 96 clockspring has one less wire, since the feedback is resistance based instead of individual line for each button?
You've already messed with adding an external switch. Why go one step further and jumper the pins at the connector at the base of the column to enable speed control and add a button to simulate hitting set? If you directly control what the ECM sees, then you can prove or disprove that as the problem.
I don’t think it’s one less wire. Both switch panels have 4 pins, but the connector at the back of the clockspring, the c225 one, has 4 wires instead of 5 in 1996. My 1995 has 5 wires, but both clock springs show having 4 wires at the switch panel.
As far as the switch went, I tried making the PCM think the switch I wired up was the actual set switch, and since it operated on grounds, where the PCM receives zero volts to tell it when to set the cruise. I had wired one side of the switch to the back of the connector at the back of the clock spring, (to the wire that was for the set command), and one side to ground, the one under the dash. The path between the switch and ground was 7 ohms, which is the lowest I was able to obtain in the cabin. The switch would work, but it wouldn’t hold my cruise after a few seconds. It just kept slipping lower and lower like the servo was loosing vacuum, but it still worked fine if I held the actual set button down.
I had to press and hold the set button, activate the switch, and it would cruise, but only for the length of time I actually held down the set button before flipping the toggle switch.
Something else I noticed when I was testing at the PCM was that every time it said that there was 12 volts at a certain pin, and depressing a certain button would cause it to go to zero, I never actually got zero volts. but more so .2 volts.
I also found this in another service manual that someone sent to me, and i’m going to try it on my lunch break tomorrow and see what I find
I don’t know why that section was included. I couldn’t get any resistance with any of those steps, and that’s most likely because these are switches, and that would make sense since I either got infinite ohms or 0 ohms.
Anyway, I went though that manual, since it told me a lot more things to test, and pretty much every step I followed eventually led to “replace PCM”.
I’ve been thinking about replacing my PCM for a while now, especially since I found out I have the wrong year PCM. Despite the PCM receiving the same inputs for each pin between 1994 and 1995, it still doesn’t seem right that the old turn signal style cruise control switch operates completely different than the bottom mounted switch panel in 1995. I’ve also been having some PCM related issues, like random codes that just pop up and go away, or weird drivability issues like cutting off or sputtering. It’s also really old to begin with, so why not?
And a lot of other people that work on these Jeeps tell me that it’s possible that the PCM has lost its memory function, and that it can’t really remember much anymore, like adapting to my driving or remembering the speed that was set.
I just don’t think a different clockspring will fix this either. I finally found a picture of one from 1995, and it looks exactly like mine. Same colored wires in the same positions as mine. And, when I called around to junkyards, all the clocksprings had the same part number as the 1996 clockspring, despite most of those XJ’s being manufactured in early 1995, like mine
05-30-2022, 08:22 PM
