OBDII Linking Error

[hbar..]

Originally Posted by cruiser54

try touching the harness further out on either side.

I didn't mean that to be so literal. We've moved around the harness in that general area. It goes directly into the fuel injectors so there's not much play there. The other end goes down to the CPS but the whole issue is so hit & miss.

Going wheeling this weekend, so we're going to leave well enough alone for now. After that we'll open up that harness and see what sort of mess we find.

[Rob Mayercik]

Originally Posted by hbar..

the key on 3x trick doesn't seem to put codes on the odometer, but I've literally never gotten that to work on any jeep.

Little late to the party here (and I know it sounds like a different reader got you codes), but noticed the bit about the key on-off trick.

Far as I know, that only worked on the 91-95 XJs, and it used the CEL lamp to blink out the codes (I've used it on my '92 a number of times). I've never heard of a key trick that worked on the OBD-II models.


Rob

[hbar..]

I've got the key trick to work on my 02 TJ, but not on my 97 TJ.

The problem is so hit & miss, we don't know if different readers work better, or if it is purely something under the hood. He's buying a harness off a wrecked 99 XJ and I think we're going to wire it in tonight. It will either make everything better or it won't.

[hbar..]

Next update. Picked up a "like new" harness off a 2WD 99, well really just the section that includes the TPS/MAF/IAC/crank & cam sensors. Harness was in great shape, am thinking it was a replacement due to the overall color & condition of the loom. Anyway, you probably knew that the 2WD harness didn't have the wiring for the 4WD light. But you probably didn't consider that the wiring for the speedo is a decent amount shorter since it doesn't have to reach the transfer case. Also the oil pressure plug is ever so slightly different, but we can worry about that later.

Anyway, new harness, still initially got a linking error. Fired the thing up w/o any problem, and then it linked. It was already 1am so we didn't mess with it any more.

[hbar..]

We ended up inspecting every inch of the original harness, and replaced the couple of connectors that were in bad shape and a few lengths of wire that were bare or brittle. Unfortunately nothing changed with respect to our ability to read codes. It was still a worthwhile exercise. I've re-taped & re-loomed several XJ & TJ harnesses, and every single one of them has had some hidden wiring issue that was just waiting to ruin your day.

However, I recently got a new bluetooth reader so I brought it over and tried it on his jeep, and it connected right away. I know somebody suggested either in this thread or a related thread that XJ's seem to be picky when it comes to readers. I guess I can live with that, but it still strikes me as extremely odd that 2 different readers that used to work fine now won't communicate. But I guess this is resolved for the time being.

Thanks everyone who followed along.