Hi, folks. Question: I believe a need a scan and ECU reset for my 1998 Jaguar XK8, asap, to fix assorted problems, including that the driver's seat back is overly reclined and won't go up, "check engine coolant" light goes on intermittently, automatic key doesn't always work, etc. (No: a hard reset will not fix these problems, and no: I have no reason to believe they are unrelated to computer faults.) All of this happened a few years ago, and after a hard reset (or 3) didn't help, I took the car to a Jag repair person specialist near where I used to live (and no longer live). He fixed these issues with a reset, I believe. So, should any mechanic with a scanner be able to handle resetting the ECU and correcting faults, or do I need to take the car to a Jag specialist? (Naturally, this happened just before Labor Day, and the specialists I contacted are closed until next Tuesday. I have to drive the car on a trip, before then, and prefer not to do so lying down.

ALSO: Can someone recommend a good but not-too-costly "battery tender" or whatever you call the thingy that remains near the battery and keeps it from running low?

Thanks for any advice!

 

M, I have a 98 too. Let's try to break it down.

Seat: does it move back and forth? Up and down if you have that option?

What happens if you press the seat back tilt button in either direction? Can you hear the motor running?

Do you have seat memory programmed into the memory buttons on the door? What happens if you press 1. Or 2? (If this works = bad switch)

It can you unbolt the seat to get a look at the wires/seat module?

If the other seat functions work, your getting power. Not an ECU issue, likely module or wiring.

Low Coolant: you said coolant level is good = common problem, bad float in the brown coolant tank. New tank is available at your auto parts store. Cost about $30 plus lost coolant. Time to install = about 25 minutes. ONE THING: expect the hard plastic tube that runs across the Jaguar cover to break. Have a 3 foot length of rubber tube and small pipe clamps ready to bridge the break or to just replace the tube. Cost around $4.

Automatic key: I may know it by a different name. Can you describe what you are referring to?

John

 

Thank you for your interest, Johnken. But I went through all of this about 3 years ago -- here: https://www.jaguarforums.com/forum/x...e-help-164588/

And it turned out that none of the individual parts needed to be replaced. Instead, a reset (or something like it) took care of them all.

 

+1 to Johnken’s comments

Referring to your 2016 thread, worth looking at Bobroy’s comments on checking battery, cables, high power fuses, and ground connections. 12V isn't a lot and corrosion at these points can cause all your strange issues.

FWIW, as cars age, they’re not 100percent and your old alternator may not be up to the task for a non-daily driven car. Do you put the car on a battery maintainer/tender?

 

Thanks, David. I don't drive the car that often (especially lately, due to additional issues), and the battery has died a few times in the past year. I NEED to put the car on a battery tender and have asked for recommendations of a not-too-costly one.

 

My preference is the ctec.
ctek 3300 eBay

Deltran Battery Tender Jr. 12V Maintainer Jr 12 Volt Harley 750 mAh 021-0123 734357000078 eBay

 

Thanks, RJ. Is this the Ctek 3300 you mean? (There seem to be several items with "Ctek 3300" in their names.) https://www.ebay.com/itm/Ctek-Batter....c100005.m1851

 

That looks like the one I have.

 

Still hoping someone can answer my main question (posted in subject line of Message #1).

 

I know this isn't the answer you want to hear, but I would swap the seat modules before doing anything with the ECU.

 

M,
Maybe you'll get more traction if you explain what you mean by reset. Do you mean reprogram? Are you referring to setting sw permissions?

I'm not an expert but the only reset I can think of can be accomplished with a hard reset. As I recall you've tried that a few times.

Not to pissyou off,but is it possible someone once fixed something and just said they reset the ECU?

Take this the right way. It doesn't sound like your symptoms match the stated solution. Are you thinking there is a sw setting preventing the seat back from moving?

John

 

OK. I was wrong to use "reset." Sorry. I have reviewed the work order from 2016, when a Jag specialist fixed many of the same problems I am having now (plus others). He did the following (among other things).

"Test electrical system. Trace most electrical faults due to body processor and driver's seat module faults. Reconfigured body and seat modules, which has corrected [the following faults, which I have again]": Intermittent low coolant warning; seat recline functions inoperable; window stop memory inoperable.

 

Reconfigured could mean many different things.

Did he open them and resolder bad joints? Did he find fuses that were blown? He doesn't really describe what he did.

 

+1 for the CTEK 3300. I've used this model on my 2001 XKR for 5 years or more and never (touch wood) had a problem after winter layup.

 

Ok looks like this recurring problem (seat back) was once fixed by working on the driver's seat module. They mention BPM unclear of itsroll in the failure. Besides that falling seat module is far more common.

Passenger seat reclines right? Can you try swapping the modules?

John

 

For that work, this (EXPENSIVE) mechanic charged only $200. (As I recall, that would be about 35-45 minutes of work.) I don't believe they did anything like soldering; I assumed it all involved "resetting" (correcting faults) electronic systems. That's all I know.

 

Thanks. I bid on one yesterday, on eBay, but I lost the auction. Will order one on Amazon soon.

 

All I really want to know is: can a decent mechanic w/out Jag expertise likely do this work, or would it need a Jag specialist?

 

I imagine that if he replaced fuses he'd so state on the bill. Probably the same for any soldering. Also, when I talked to him when I picked up the car, I had the impression that it involved simply correcting faults electronically - no other labor or parts.

 

Yes but the Deltran is less than half the price.