My 97 XJ6 134k miles has an electrical problem. Starts fine at first then dash lights all start flashing, the car sputters sometimes and dies sometimes but dashlights flashing is constant about every 30 seconds. I've bought 2 ECMs off of Ebay and am getting the same problem with all three ECM's so I don't think it's a bad ECM. I've switched out all relays so I don't think that's it. I've replaced TPS and CKPS. I've pulled out the passenger airbags and all of the dash components so I could clean all of the connectors under there and still no luck. Also replaced the battery. It's as if the ignition switch is shutting off for a split second and then coming back on. I'm thinking of pulling the engine wiring harness and replacing it, or would the dash wiring harness be more likely the culprit. Or could it be something else altogether. I'm determined to find the problem. If someone can help me with the next logical step I would greatly appreciate it. Bought the car used "as is" and this all started about 30 minutes into my drive home from picking it up.

Thanks and sorry for the long post,
Pat

 

When I worked at the dealer several years ago we had an X300 (1995 with 240,000 miles) car that had some of the same faults. After days of driving with WDS monitoring the ECM it would go blank and restart as if the ECM shut down. We finally determined that one of the 'on-plug-coils' pimary circuit windings was short or open circuit causing the ECM 'hiccup' and restart the computer. The coils were replaced and the fault was resolved. It was only one coil but which one?? There was no DTC for the coil failure so you can guess and hope the ECM faults a specific cylinder. Pull them out and look for cracks/defects in the individual coils!!

bob gauff

 

A couple of questions- Do you have a 12 volt test light? A voltmeter? Do I understand correctly that the dash light flashing ihappens continuously? If so, I believe I can walk you through finding the source. And if it is as if the ignition switch is shutting off, have you tried replacing it?

 

Thanks all.. I have a 12 volt test light but not a voltmeter, I can go buy one though. The dash light flashing is not really continuos but it doesn't go more than 30 seconds without lighting up. I've thought about the ignition switch so I hotwired the car by unplugging it and using a couple paperclips to get her started. Also going back to what Bob posted about the coils, I will try to eliminate that as the problem tonight.

Thanks,
Pat

 

OK- then we need to check the power supply to the ecu- It is in the right driver kickboard. Take a look and see if you can understand how to get your test light onto a terminal (without shorting it to another !)

 

AAAAAHHHHHH!!!! I think Bob nailed it. I just got home and started the car. Let it run until dashlights started flashing and engine started sputtering. Unplugged 1st coil and engine ran rough, dash lights still flashed periodically and engine sputtered periodically. Plugged it back in and unplugged second coil from the front-rough idle due to running on only five cyl. but flashing dashlights and sputtering has stopped - been running like that for 30 minutes now and that seems to be the problem. Think I got it? If so, I want to thank you both for your help. This forum is the best.

 

Sounds good at this point! Bob has a bunch of experience. Congrats.

 

Wow, that's practically the identical problem I'm having right now with my '97 XJ6. The whole instrument panel flashes, engine stalls at low revs but starts right back up, sometimes it revs-up a bit by itself. But all of this happens only after 30-45 minutes of driving. When the engine is cold, no probs.

I took it to my Jag tech, and he'd never seen that problem before. The diagnostic codes were P1314 (Misfire Rate Catalyst Damage Fault - Bank 2) and P0300 (Random misfire). He thought it might be the ECM, so he was going to swap it with the one in my '96 XJ6 to test it, but the models didn't match up. He hooked up a fuel gauge, and the fuel flow was fine. So now he's looking around for an ECM, but hearing Pat's story, I think this may all be for naught.

My car is still sitting there in his lot. When he opens on Monday, I'll definitely check out the coils. Come to think of it, I did smell a burnt plastic odor under the hood during one of these episodes, but I couldn't find the source.

I love my X300s, but all these sensors and electronics bog me down - sometimes I wish it looked like an old Chevy under the hood. And Pat, I suspect that guy who sold you your Jag was hiding that problem from you, seeing as how this particular bug doesn't show up for 30 minutes. Hopefully it works - either way, thanks to all of you on this forum - what the hell did people do before the internet? Pay their mechanics a hell of a lot more money, and purchase actual **** magazines, I guess.

Sorry, this post is long, but one time when I was driving during the crazy dashboard light show, the odometer display read "AIRBAG". I put my hand out in front of me half-expecting the bag to go off.

 

Ralph, when my Check Engine Light came on a couple months ago, I had the same EXACT two codes. Cleaned out my Throttle Body with some Carb and Choke Cleaner. Had light shut off and it's never come back on since....better MPG's as well!

 

MTZGR777,
Were there any other symptoms other than the check engine light? I'll keep the throttle body in mind, but I definitely also have an electrical issue. I may have both problems going on though, because I've never cleaned the throttle body on this one, and it's at 177K miles now. That may explain the short bursts of revs every now and then when the instrument lights start to flash. I should find out by tomorrow.

 

Holy Crap!
Pat you just saved me a lot of money and aggravation. It was the #6 coil, just like you said. I got a good coil from my other XJ6 and just started replacing them, one by one. I got to #6 last, mainly because I just had the Jag shop put that one in brand new about 9 months and 15K miles ago. What the hell? I noticed that the "new" coil just said "PEC" on it, whereas the original ones all had model #s and said "assembled in the UK". So is "PEC" a cheapo aftermarket part? And where's a good place to order coils?

Also, I think I need to clean my throttle body because the revs are taking way to long to settle down at idle. Everybody on this thread got it exactly right! I think you guys may have not only saved me a bunch of money and aggravation, but I think you also saved my rosy outlook on the Jaguar brand from severe disillusionment. Thanks!

 

Ralph, I'm happy for you. I know how excited I was when I found it was the bad coil after 6 weeks of searching but Bob deserves all of the credit. If it weren't for him my jag would be sitting in the driveway now with the wiring harness ripped out and me still confused. I too now have a new rosy outlook about the jag.

 

Im glad you guys figured it out. What a great help this forum is. Im not very mechanically inclined so I cant add any input to the electrical problem but Ralph, when you mentioned the air bag light came on and you thought the airbag might deploy so you put your hand in front of your face....not the best idea...If it were to have deployed for some strange reason your fist would have been slammed into your face due to the airbag sending it there. Haha my 2 cents
Keep up the good advice & lending your expertise to less mechanically inclined people such as myself.
Aloha fellow x300 club members

 

hello all just purchased 95 XJ6 love this car but no dash lights and trunk release not working

 

Welcome to the forum Brad. I don't have an answer for you but I recommend starting a new thread rather than tagging on to an old one. You'll get more exposure that way.

 

I didn't have a warning light problem but did have an HT ticking on the radio which was at the same frequency as half the rpm. One of the coils had an earth fault. Unplugging them individually identified the culprit which was replaced. No more "ticking"

 

Coils are a problem for these cars. The OE ones are made by Diamond in Japan, and last a long time. Everything else seems to be junk, so I'm not surprised that your new coil is the one that failed. Given my choice, I'd take a good used OE coil over a new one not made by Diamond.

There is a massive thread on coils and their failures, see here: https://www.jaguarforums.com/forum/x...0-coils-93966/

BTW, the dash looking like a christmas tree lit up is a classic symptom of one or more bad coils.

 

thank you

 

I had misfires in both bank 1&2. It wasn't until I had my O2 sensors calibrated that all of my issues went away.