Hi guys, I need some input on my recent "Engine Systems Error" issues.

I'll give you some background. I bought the car last August from a private party. 2005 Super V8, in great condition, full service records (mostly from the Jag dealer), 126,000 miles.

This is not my daily driver, and it's only been driven about 2,000 miles in the past year.

A week or so in, I got my first "Engine Systems Error." I was parking the car at work, and I shifted from reverse to drive without being fully stopped. I usually never do this, but I still wasn't fully used to the car yet. Anyway, as soon as the car shifted from reverse to drive at almost zero miles per hour, it threw the Engine Systems Error / DSC Not Available / Park Brake Fault. I parked, turned off the car, and it was fine later on in the day. No more error.

This same exact thing happened a couple days later, and again, it went away after the car was restarted. But since then, the same error has come up when I've started the car intermittently. I can make it go away by restarting the car a handful of times. It's never occurred while driving, just starting the car.

A couple weeks ago, I got in the car to drive home from work, and it threw the error, but I could not get it to go away at all, no matter how many times I restarted it. I was about to have it towed, but I decided to leave it in my work parking lot for the weekend and figure it out the next day.

After "driving" the car around in limp mode for about 10 minutes, I turned off the engine, and I decided to try one more time to turn it back on with no error. Bingo, it actually turned on like normal and I was able to drive home. It's been in my garage since then.

Here's what I've done in the past six months while trying to figure out this issue:
I have a couple ideas as to what this could be.

At first, I thought it must just be the TPS / Throttle Body based on what I've read. But, the previous owner had the TB fully replaced four years ago. Could it still be that?

I also have been thinking it could be that the battery is bad because of how little the car has been driven in the last year. Again, the prior owner put in a new Bosch ACG Group 49 battery less than a year ago, but it hasn't been driven that much, and has had a couple periods of sitting for a month or so with no driving.

I just tested the battery yesterday after the car has been sitting for about 2-3 weeks.
Not sure if these numbers are normal or not.

I'm basically trying to figure out what my next move should be. I don't want to replace the TB if I don't have to.

As an added bonus, when I started the car yesterday, a decent amount of white smoke came out of the exhaust for about 10 seconds, then there was still a little bit coming out after two minutes. It appeared to be only coming from the driver's side exhaust. Maybe this is just from not running the car in a few weeks.

I'd appreciate any insight. Thank you!

Justin.

 

Is there any seepage of fluid from the TCM socket at the back of the transmission ? The TCM and the ECM exchange information via this plug and socket. The seal fails and fluid can then contaminate the pins and maybe cause an information error.


Just a thought.

 

I'll try to check that out. Where would I look?

I've never noticed any actual fluid leak under the car.

 

Battery's not bad for sitting that long and alternator looks fine.

I'd try charging the battery, leave it connected to the car but without engine running at all, then re-measure after a few hours.

Also, try a load test to check the volts don't drop too far during a heavy load.

 

+1 on the battery as well.

 

You have to have a good battery on one of these cars or you will get fault codes galore if you have a good battery then go from there if you search this forum you will see a lot of problems are down to a faulty battery.
If you don't use the car much it's best to connect the battery up to a charger that can be left connected like a ctek charger

 

Thanks for the advice guys. Here's a small update on what I did yesterday.

Battery charge prior to starting: 12.13V
Battery charge immediately after starting: 14.41V

Got the Engine Systems Error.
Ran the car around my neighborhood for 15 minutes in limp mode to let the battery charge up.

Battery charge with engine off: 12.79V
Engine Systems Error still there on start. 13.84V

Rolled around with the car on for another 20 minutes.

Battery charge with engine off: 12.81V

Car started without Engine Systems Error and drove normally (but with check engine light on).

Filled the tank, drove home, and left the engine off for 30 minutes.

Battery charge with engine off: 12.64V
Started normally (no error).

Drove for about 30 minutes, totally fine. Came back to the car after two or three hours, and it started with Engine Systems Error. I didn't check the battery charge prior. Left the car on for about 15 minutes and it restarted without the error.

Drove home, washed the car, and after another three hours, it started with the Error Again.

So...

At this point it seems pretty clear that the issue AT LEAST is mostly the battery. Maybe something else coming into play, but the battery definitely affects it.

Luckily, the battery is only 10 months old and is still under warranty at Pep Boys. I'm going over there this weekend to have them check it and hopefully replace it.

Any other advice is appreciated.

 

Engine light (MIL) - Read codes.

Probably not the battery.

 

Throttle Position Sensor on the throttle body? Quite a few posts on that one.

Check this puppy out:

https://www.jaguarforums.com/forum/x...-issue-132663/

 

Yeah, I'm pretty familiar with the TB/TPS issue, and I was about ready to replace the TB again until I realized it seems to be the battery.

I'm bringing the battery into Pep Boys tomorrow, and hopefully they'll just replace it under warranty for me. I mentioned to the service guy on the phone that it had 12.13V when I check it before starting, and he said that's definitely low enough to justify a replacement under warranty.

I'll post an update once I get a new battery in there!

 

Another update.

I got the battery replaced with a new one. Group 49 Bosch AGM, same as last time.

Still the same issue!

I think at this point I just have to take it into the shot and have it really diagnosed, but I think it'll either need a new TB/TPS or possibly a Fuse Box, based on other people's experiences on here. Or I could luck out and just need a new TB connector

I'll post another update when I find out more. Just want to drive her again!

 

Alright, so I brought it to a local (and well-respected) Jag shop yesterday, and they pretty quickly diagnosed the car as needing a replacement engine bay fuse box. Kind of bummed, because the cost is quite a bit higher than a throttle body, but I'll be happy once this is fixed.