I had a strange problem this morning. On my way to work, car failed, and lot of warnings came. ENGINE FAULT - TRANSMISSION FAULT - STABILISATION FAILED to name juste the most frightening warnings.


After searching on the forum, I have read many post that were answered, "have you tried an hard reset ?". Pretty much all I those that I read were not solved by this.


Then I remembered opening the trunk many times last friday, opened the top once, then closing it, all on battery... After 3 days sitting there, it started properly this morning, but ran for less than 5 minutes before everyting failed.


So my theory is; the battery went low, the car started ok anyway and was charging on my way. The alternator might be giving too much "square waves" to the electrical system and since the battery was low, it was not able to absorb them all, the ECM didn't like it. I'm not a mechanic, so I say it in my own words, my apologies :-)


I had the ECM done by A.S.I. last year, so I figured "maybe it is a maintenance to be done every year now"... Doing an hard reset made the car run flawlessly.


Here's what I did:
- unconnect the negative battery pole
- with the help of boosting cables, I shorted the positive and negative wires for 30 sec. (NOT the battery poles of course :-))
- then reconnect the battery properly
- then boost the battery with a running car, while connected
- then it started like a brand new cat.


In a dealer: it would have cost me over 1500$ for sure. I doubt any car dealer would try this solution before starting to cahnge all the ECM/TCM etc.


This solution is free, so don't hesitate and give it a try when you experience strange things !! It worked for me !!!


Thanks to www.jaguarforums.com for saving me soooo much money every year :-)


Happy me !

 

Computers HATE low voltage!!!!!!!!!!!!!

Good thing you did the hard reset but make sure the battery is good.

bob

 

I hope you have a way to charge your battery if the car is not used for long enough runs.

Also, according to the owners manual, when jumping from another vehicle that vehicles engine should not be running.

A hard reset does not require disconnecting the positive cable, just disconnect the negative cable and touch it to the positive terminal.

 

Thanks RJ237


I actually unpluged the negative only, but it was too short to touch the positive, being screwed to body right behind the battery, that is why I used boosting cable to connect them together.


Never unplug the positive first, as the toll might be shorting to body/ground and transform in a nice soldering tool, or an expansive lighter.


I left the other car running, just because I didn't want to end with two stuck cars, but you're right, the car should idealy not ne running.