I have a 2002 xj8. It drives beautifully, but then randomly, I will go to the store, park the car to go in, come out, and it cranks but won't start. It says
failsafe engine mode,
transmission fault ,
trac no available
asc not available

It happens randomly. I have had people give the battery a jump and it sometimes starts, but not always. Mechanic says its not the batter. (I got a new one anyway). If I leave it overnight or for many hours and comeback it starts like nothing happened. I take it to the mechanic, they can't find anything. There are never any codes. It starts fine. This happened last week. I had them test everything, give it a once over, change fluids, check plugs. etc. They couldn't find anything. Then last night... It sat all day, then in the evening I went to home depot. It wouldn't start. Wouldn't start with a jump. Had it towed to mechanic. They come in this morning it cranks fine. No codes. I have a code reader, but when it goes in to failsafe... it won't connect to the code reader so I can't clear anything. But it never has any codes when this happens anyway.

I've been reading the threads.. It does NOT go into reduced power mode while driving. There is no indication of anything until it just won't start.

1. Any Ideas? The mechanics have none.
2. Is there anyway to reset or get it out of failsafe mode when there are no codes?

Help... this has been happening intermittently for 3 years, all lights work, the fuel pump is fine. They replaced plugs, cruise control works. I don't know what to do.

 

My '03 XJ8 had similar issues for years. After several misdiagnosis' by 3 mechanics, I traced it a loose multi-pin connecter above the fuel tank. Go through the rear trunk, roll back the carpet from the rear trunk wall and you will see it sitting above the fuel-tank, behind the back seat. If the connection is loose it can cause intermittent problems, especially when hitting bumps while driving. It can also set off a myriad of codes. In my case, a plastic "zip tie" was all it took to secure the "connection" ... problem solved! You may have take to your local Auto Parts retailer and have them clear the codes! I hope this helps ... good luck!

 

[QUOTE=SPEEDSTER911;2411409]My '03 XJ8 had similar issues for years. After several misdiagnosis' by 3 mechanics, I traced it a loose multi-pin connecter above the fuel tank. Go through the rear trunk, roll back the carpet from the rear trunk wall and you will see it sitting above the fuel-tank, behind the back seat. If the connection is loose it can cause intermittent problems, especially when hitting bumps while driving. It can also set off a myriad of codes. In my case, a plastic "zip tie" was all it took to secure the "connection" ... problem solved! You may have take to your local Auto Parts retailer and have them clear the codes! I hope this helps ... good luck! BTW ... the multi-pin connector is located on the right side, US models.

 

Ok. Thank you. Its still at the mechanics... who called to tell me he couldn't find anything. When I go to pick it up, I will ask him to check this. So frustrating I love this car. It is such a smooth ride. This just make is totally unreliable.

 

If you have an OBDII ECM reader, try to communicate with the Engine module when the NO START happens.

If I were diagnosing the car I would read ALL the modules to see if there is a fault on the CAN bus and a module points to a network fault OR another module 'NO COMMUNICATION'.

Could also be a faulty INSTPK causing the 'parade' of faults in the display.

All the faults point to a CAN bus issue.

 

I do connect it to an OBDII reader when the failsafe happens... it won't connect. It connects when anything else happens... but not when this issue happens. The mechanic says he's been through the diagnostics and modules and can't find anything. The fuel pump connector is not loose. I'm at a loss. I don't want to keep paying the mechanic to say the same thing.

 

That is why I like to interrogate the OTHER modules on the CAN bus to see if any report NO COMMUNICATION ECM. so you can see where in the wiring the modules might be disconnected/faulty.

The INSTPK is at one end and the ABS is at the other.

The network connects them all in between.