I have a 2000 XK8 Coupe. I've brought this up in the past, but for the past four years when I try to start the car, about 50% of the time it will not start. It will give me four warnings when this happens 1) Gearbox Fault 2) ABS Fault 3) Trac Fault 4) Reduced Performance (I may be a little off on the exact words as I can't reproduce this on demand). Most of the time, there will also be a beeping that occurs when I turn the key to Accessory mode (right before you actually crank the ignition). If I keep performing the start-up procedure (slowly turning the ignition off, removing the key, letting everything shut down and cycle, then putting the key in and trying again), eventually, from anywhere from 30 seconds to 15 minutes, the warnings will clear and the car will let me start it 100% of the time.

I've had the car into a very good Jaguar specialist for this problem about three times. Usually it won't happen while the car is there (of course!), but one time it did happen. They couldn't find any codes in the system that they could use to diagnose it. One of the techs took it home overnight (with my permission) and it happened again. He noticed that the fuel pump wasn't clicking and didn't appear to turn on when this condition occurred. He checked the fuel pump relay and found some minor corrosion. He cleaned it up and it did not happen to him again. When I got the car home, it worked okay for a few start cycles, but the issue came back again shortly. I did the same thing, I double checked and cleaned the relay, which then enabled me to immediately start the car, but in the future, the problem just kept happening (about 50% of the time) up until present day. It doesn't not appear to be just the fuel pump relay (if that's even part of the problem at all).

Has anyone experienced this and does anyone have any thoughts on what is causing this? It's very frustrating not being able to start the car for up to 15 minutes half the time, not to mention I could never sell the car with this condition. It always starts eventually and it drives very well once it gets started. Thanks in advance -Chris

 

Does it crank when it won't start ? How is the battery ? Does the ground strap on the battery get hot ? I will get the "TRAC NOT AVAILABLE" or something similar right when starting the car if the battery is a little low. It seems to be the first indication of low voltage.

 

The symptoms are all the classic failing battery symptoms but presumably a new, fully charged, battery will have been tried as everyone knows that is the first step.

Relays are very inexpensive so I would change it for a new one just to rule it out.

Richard

 

It will always crank when it won't start. Battery is maybe three years old and is kept on a slow charger, so didn't think much about the battery. Haven't checked the ground strap. You're right, I usually get the "TRAC NOT AVAILABLE" for a quick moment even when it does start.

 

Richard, Thanks, I'll buy a new relay to at least try that route. Never messed with the battery as it's maybe three years old and is always on a slow charger, so didn't think it could be a problem. The problem has pretty much always been there, even after I got the new battery installed.

 

Check that the ground strap on the right side of the bell housing is clean and tight.

 

Thanks, I'll check that.

 

Are you keeping the battery on a quality tender (CTEK, NOCO Genesis, or Delran battery tender+, etc whenever the car is not being used overnight or longer ? Just doing that will banish most electrical gremlins.

Heres a work-a-round for a shifter issue you
might have (I did). :

After you put the key in the on position, step on the brake to release the shifter solenoid. Then with your foot still on the brake, shift into Neutral, now turn the key to the starter position . If your car starts without any **FAILSAFE** or similar warning, then you’ve likely an issue with the shifter mechanism needing some attention. Hopefully just an adjustment.

good luck.

Z

 

Chris,

In addition to the previous excellent suggestions, I would recommend disassembling and cleaning all the battery power and ground connections between the battery in the boot and the fuse boxes in the engine bay, including the battery ground connection to the body, disassembling the fuses from the High Power Protection Module on the forward bulkhead of the trunk, the power connections to the fuseboxes, the false bulkhead connector, the connections to the alternator and starter, etc. Every connection is susceptible to corrosion, and even light corrosion on these connections has a cumulative effect. Oil contamination on the alternator, starter and engine ground strap terminals is also common. If the voltage to the ECM sags to about 10.5 volts while cranking the engine, the ECM will not trigger the ignition to fire. The actual voltage sag is difficult to measure with a digital meter - an analog meter is faster-reacting.

The engine ground strap is notorious for internal corrosion, so you really should remove it, clean the body and engine connection points, clean the eyelet terminals and nuts/bolts and washers and inspect for corrosion inside the eyelet terminal crimp connections. I have added an additional "bypass" ground strap anytime I've suspected the original ground strap of a problem. Short battery cables with eyelet terminals are available at any auto parts shop and they are very inexpensive.

Also, I would replace not only the fuel pump relay but all of the Ignition On relays in the various fuseboxes and the main Engine Management System relay. Bosch makes suitable replacements that can be found at very affordable prices. The relay locations are all shown on a diagram in the Electrical Guide, which you can download at our member Gus's website, jagrepair.com.

I make it a practice to clean any battery power or ground connection that is nearby when I am working on my Jags, which helps to reduce the instances of these kinds of issues.

While the battery is disconnected, it's not a bad idea to remove and reinstall all the relays (and fuses if you're up to it) to help reduce the effects of corrosion on the terminals. Also, remove the cover over the ECM and disconnect, inspect, clean if necessary, and reconnect the electrical connectors to the ECM and other components there (battery must be disconnected).

Cheers,

Don

 

Z, I jumped in the car just now and tried to start it. The "four warnings" scenario came back and the car wouldn't start. I then turned the key anti-clockwise a click, put my foot on the brake, and shifted into neutral. I then tried to start the car, but it would not start, and then it started yelling at me with a loud, quick pulse, as it does when the shifter is not where the car wants it to be. I then shifted back to Park with my foot on the brake and all four warnings immediately went away and I was able to start the car up. Thanks for the tip, you may be on to something. I'll now monitor it and see if it gives me the problem again and if it does, if your technique solves it, as it did this time. If it always solves it, then it looks like the problem may be a shifter adjustment is needed. Speaking of which, when I bought the car, it had a myriad of shifter sensor issues that cost me thousands to resolve, and it seems like the issues were never all resolved. I hope we are onto diagnosing and repairing the problem permanently.

Also, the battery tender is a Die Hard. It seems to work just fine. When I checked it 10 minutes ago, it had the battery fully charged and was just monitoring it. -Chris

 

I'm new to Jaguars but not new to electronics so these thoughts are just off the top of my head. Oh, I have a 2000 XK8 but none of these symptoms (yet!).

I am a bit surprised by the apparent sensitivity to battery voltage that these cars show. I note that you have said that this has been going on for 4 years. Also it sounds like you replaced the battery 3 years ago and keep it charged - So, at least part of the time when you were having this fail to start condition you had a fully charged/strong battery.

Cleaning all the contacts is good SOP in my mind and checking for excessive voltage drop by seeing if the headlights dim when starting is a normal test too.

Regardless it brings me back to the question - "what is a root cause" of the failure to start, codes and general wisdom to check the battery first. It makes me wonder if the electrolytic capacitors in the ECU are bad and in need of replacement.

I'm not suggesting that you ding into it right now but have others solved starting issues after a cap replacement? Here is at least one: https://www.jaguarforums.com/forum/x...ndition-83360/

I'm still working on other issues on my new to us XK8 (See my signature) but I'm thinking that a look at the ECM is somewhere in my future. There is a good writeup on how to do it too if only I can find it again.

Best!

 

Don, thanks for the tips. I may be on to something with the shifter works, as referenced above, but I will also start to do your above tips, and that can only help my situation. Thanks a lot.

 

2000 MY XJ/XK cars have a CAN bus fault with the INST PK.

Check yours.

 

Thanks. My car is in the VIN range, but it displays none of the faults associated with your attached bulletin. That being said, I will keep this in mind going forward, as it could still be a problem, but I'm going to try to work small to big on this. Removing the instrument cluster is a large job if I can find the fault at hand elsewhere. I may be on to something with shifter adjustments. Regards. -Chris

 

re the shifter location; as far as I know, all years should should start in the NEUTRAL shifter position. I always have my foot on the brake to ensure I won’t start rolling, not sure if they matters
or not in regards to the the car starting OK in NEUTRAL.

PS: I’ve just gotten in the habit of starting the car (2002 XKR) in NEUTRAL. To me it’s the new normal.

Z

 

I just went out and shifted the car to neutral to start, and it started up fine. It wouldn't start earlier in neutral because it still had the four faults displaying. For now, I'll start cleaning various terminals, relays, and grounds, but I'll keep monitoring the shifter issue before I try any other repairs. Thanks again.

 

For what it's worth, I think the problem is partly that the battery is in the boot and has a tortuous route forward to the engine management fuse box (and elsewhere), rather than being in the engine compartment right next to the computer. As Don B has suggested above, the various connections can get dirty/loose over time, leading to a voltage drop that gets worse when cranking, especially with an older battery.

A simple check for how good your connections are is to check the voltage at the battery itself and then again at the engine compartment fuse box 12V stud, either taking ground from the engine (if you can find a clean bit of metal), or the bonnet latch. Do this with the ignition on and the headlights first off, then on. You would hope for a difference of less than 0.25v - anything more would suggest poor connections along the way from the battery. Multimeters that can record max min values (and ones with oscilloscope functions) are so cheap these days, it's well worth considering one as part of your toolkit and can show exactly how far that battery voltage drops when starting. I think I would buy one of those first before taking the ECM apart to check for bad caps - but then I'm of the if it ain't fuxd don't fix it school of thought.

ETA that's not to say I don't think bad caps can be the issue, just that people need to get in the habit of checking power distribution first (fuses, relays, powers and grounds) before deciding to send their modules off to be rebuilt.

 

Thanks once again for all the great tips. Time for an update. I decided to replace my broken shifter surround plate (a shop had screwed the lower attachment screw too much, through the threaded shaft and into the piece itself, which cracked the whole plate about two weeks after I got my car back from the shop) I also wanted to try to repair the circuit board that has all the lighting, as I had a burned out lower bulb and a burned out LED bulb at the "D" position. I also thought maybe I could poke around and look for shifter issues, since I suspect a shifter issue would be the most likely issue with the starting problem, which is the main purpose of this thread. As far as the starting issue, out of about 5 starting tries, it did not happen. After about 6 starting tires once I got some of the shifter apart, the problem happened only once, and this went away quickly with some manipulation of the shifter mechanism. At this point, I'm about 90% sure the problem is shifter position related, but I'm not to the point of determining the specific problem with the shifter. I'll recheck, reposition, and retighten everything once I get the lighting issue solved, then I'll do some further testing to see if I can eliminate the start problem altogether. I do think I'm on the right track. Cheers!

 

Another update. I've made slight adjustments to the shifter, cleaned the shifter mechanism the best I could, and I've now had about eight start-ups with no warning messages at all. I think this solves the problem. Thanks for all the excellent tips and recommendations.