Hello everyone, I’m new here. Kinda at wits end with this issue on my sons 01 xj8. Intermittently when he goes to start the car he gets a few error codes: Trac not available, ACS not available, transmission fault, failsafe engine mode

if he keeps retrying the key over and over eventually it starts but it’s making him late to places.

Twice now it has died going down down the road and not wanted to restart

It doesn’t seem to have anything to do with time of day or humidity

Recently we replaced the security module to fix the passenger side tail light not working

Weve tried pulling the battery cables and touching them together

we have replaced the battery, even though it wasn’t that old

we just got a used but supposedly working throttle body off eBay and replaced that

I’ve checked the connectors at the abs module.

we took it to advanced auto to read codes. Took them a while to figure out how to read the codes but all that came up was p1111- which I guess means everything is good??

I really want to help him but I’m at a loss with this car. No idea

please help!

thanks in advance

 

out here trying to start it now. Just getting Trac not available, asc not available, transmission fault. And this time getting incorrect part fitted, engine failsafe mode

 

The radio just says “enter code” not sure what that’s about.

 

Tried messing with a bunch of sensor connectors, nothing


pulled all relays under the hood and tapped them a bit in case they were stuck. Car starts now. 6 times in a row. Hard to tell if that’s chance or if a relay was stuck.

 

Hi Paul,

I have moved your posts from the forum for the X350 to the forum for the X308, which is the Jaguar factory project code for your son's 2001 XJ8. Here you will find knowledgeable owners of similar cars.

It is likely that the issues causing the warning lamps to illuminate are also triggering Diagnostic Trouble Codes, but when the battery is disconnected, and especially when the battery cables are touched to one another, all of those DTCs are lost.

It is quite possible that a failing relay is causing the no-start condition.

Can you give us a little more detail, such as, when the car will not start, I'm assuming you mean the starter motor is cranking the engine over but the engine is not starting. Is that the case, or is it not turning over at all?

Was it this non-starting condition that prompted you to try a different throttle body?

Just because the battery is new does not mean that its state of charge is sufficient to start the car. If the voltage while cranking falls much below 11 volts, the Engine Control Module will not trigger the ignition to fire. Do you have a good voltmeter capable of checking the static battery voltage and the voltage sag while cranking?

I'm sure other members will have other suggestions.

Cheers,

Don

 

Thank you for the reply

ibe tried pulling the battery leads and touching them, seems to have no effect.

I have not put a voltage meter meter on the car but jumping the car or attaching a jump pack don’t seem to help

when the car is having the starting issue it won’t even crank. I read one one of these forums that his issues could be caused by a bad throttle body, that’s why I replaced it.

After getting the car going yesterday, later in the evening my son had a hard time getting it started again. I swapped each relay with the relay next to it. And the car started. I’ll have to watch and see if the problem followed the relay to whatever system it now controls

 

I also noticed yesterday during the no start condition the hvac controls say “Er”. After looking at the owners manual it looks like all of the systems that are having intermittent troubles have modules described as being located “drivers side front below abs module” or something like that, I don’t have it in front of me. Maybe there is a loose connection somewhere below the relay bank that makes connection when I am jiggling the relays.

 

Sounds like you have an intermittent ground problem. Somewhere in the stickies there is a document on chasing down bad grounds. But I would start with the ones from the two large relay/fuse boxes on the left bumper in the engine compartment. Maybe a loose wire . . .

And even more obvious: check to assure your battery cables are tight. Practically beat myself to death trying to find an issue with wife's Maxima to discover that the AAA guy installing a new battery hadn't tightened the clamps.

And while you are back there, check that the fuse box and SLCM box are dry -- trunks get water and screws up electrics.

And where are you located?

 

You could be right about intermittent ground up front. I think the car was totaled from a front end shot and fixed years ago. Looks beautiful now but it does have a salvage title. I’ll look at those connections Sunday night when I get back in town. I did tighten the one on the inner fender well, but from memory there may have been paint between the fender and washers. I’ll look sunday

the battery connections are tight, I made sure because I’ve fallen victim to that as well. Also made sure there wasn’t too much oxidation on the battery posts.

We replaced the SLCM box I believe just after this problem started because we had the dead taillight issue. I’ll check back there and make sure everything is nice and dry.

We’re in Frederick Maryland. Around an hour from dc and Baltimore.

Thanks for your help!

 

If your radio displayed “enter code” not because you disconnected the battery but after attempting to start the engine, it probably means that there was a voltage drop to just a few volts during attempted cranking, i.e. at high load by the starter motor.

I suggest you check the master fuse box in the trunk (in front of the spare tyre). It is not uncommon that the large connections to the big fuses get loose and/or corroded developing high resistance and voltage drop at high loads. This, in turn, will cause all kinds of errors popping up and no start. Unbolt the connections at this fuse box, clean well all contact surfaces and tighten back. Be careful not to overtighten as the studs are in plastic.

Another thing to check is the positive battery cable to the fuse box. It is also not uncommon that the end crimps on this cable develop high resistance inside although the look very good on the outside. Same goes for the negative battery cable. If any of the two battery cables gets warm/hot (especially near its end crimps) after cranking the engine or while the engine is running, the problem is in the cable crimps.