I am confused. periodically I get failsafe engine mode warning, recently more often. there are no codes set. most imes if you turn the car off and wait 30 minutes or so and restart it is fine. Does anyone have a hint as to where to start looking? This freaks my wife out when I am not with her.

I've moved your thread from General to X308 section where you should get a better response.

Graham

Do a search -- you will find a lot of information .... normally the cause is a loss of communication in the CAN BUS -- with your car being an early model you may have some additional issues with the throttle body. The early cars had a service action regarding the Tbody.


The first thing is to check and clean the connections to the throttle body -- you can purchase new upgraded connections if you find them at fault. The brake switch can cause this problem as well as the Throttle Position Sensor -- not available as a separate part.

When you said no codes set, does that mean you have a code scanner in the car and you scan for DTC codes during the failsafe engine warning event?

If that is not so, then maybe there was a DTC code and during the end of a driving interval, it reset itself.

It would be nice to know the timing of the events.

Note: everytime our 2001 Jag XJ8 goes into limp mode (resticted performance/failsafe), my wife also freaks out wether she is alone or with me when it happens.
It happened two different times yesterday afternoon (first a P1121, I erased it with the code scanner I have in the car, then about 30 minutes later a P1122 that I also erased).

Jim Lombardi

Jim,
New to forum. Can you reccommend a scanner. I see numerous discussions referring to codes - thinking I probably need a scanner for troubleshooting. Thanks in advance.

Hi
I purchased a generic Actron Pocket Scan Code Reader model CP9125.

This is a basic code scanner that covers Engine DTC codes. It does not cover Jaguar Specific codes in the ABS module, Body module, TCM - Transmisson Control Module, Climate Control Module, etc.

I bought at Advance Auto Parts website in March last year. It is now on sale for $59.99 on their website and you can apply discount code A123 to get $20 discount and also free shipping to your local Advance Auto Parts store (net price of $39.99).
It works well and does report DTC codes about failsafe/limp mode issues (also usually you can erase them with it).

Full blown Jaguar Specific Code Scanners run about $2000 with the Jaguar package.

Jim Lombardi

Hi,
I had a similar situation with my year 2000 3.2 V8, in that it would just cut out and would display various fault warnings. At first I was able to re-start by disconnecting the battery, and waiting 30 mins or so but eventually it stopped and would not re-start, luckily the car was on my drive when this happened. It turned out to be a faulty 40 way or so through panel multiplug, situated in the passenger footwell behind a plastic panel. Even though the plug had a locking clip the contact was poor and a jolt or vibration was enough to cause problems. I cut out the plug altogether and soldered each connection and shrink wrapped it. I have had no more trouble since. This may not be your problem, but it was in my case.

I have a scantool with jag enhancements and read the codes while the car was running and the failsafe engine mode warning was illuminated. No codes found, I'll check the throttle body connections. Thanks

Failsafe with no codes a common situation. One way to identify the cause is to install your OBDII reader and drive the car and see what takes place. I had several no code situations from the knock sensor, TB plugs & TB failure. See if you can capture the fault first.

Guys, I recently got an Ultrascan scan tool. It is nice (no affiliation, etc.) it was about $69 online. It is fairly small and looks sort of like a GPS. You can stick it to the windscreen if you want. It has 60-70 different gauges or readings, like the O2 sensors, short-term and long-term fuel trim, engine temp, HP, all kinds of stuff. I've had it hooked up for a couple of weeks and it really gives you a lot of info. It will also show pending trouble codes, current trouble codes and will reset codes. Just FYI, its a fun toy.

Oops ! I meant to say UltraGauge not Ultrascan.

JimmyL, I also have an Ultrgauge, but not everyone is happy with it. Go to the XK8 forum and see the comments about Ultagauge support by EZDriver.
Semayer, sorry to steal your thread, I will make no further off topic comments.
RJ____________
97 XK8 85K mi

I had that problem on my 1999 XJ8. I had a short and the battery was being drained. After a few minutes of driving the light went off and it was fine.