After about 3 minutes of operation (engine hot or cold) an "Engine Fault" message is displayed on the alarm panel with no other alarms e.g. (Check Engine light). An "Engine Fault" alarm is not described in my owner's manual so I don't know if this is important or not, (it is a yellow light alarm so that may imply that it is not critical). I have tried to see if it is rpm dependent or dependent on having a tight gas cap, but nothing tracks. If I wait with the engine off for about 3 minutes, the alarm clears, but it recurs after about 3 minutes of driving.


Bizarrely, once the alarm occurs, the push button to turn the cruise control on and off no longer works (no little red light) but it too recovers if the alarm goes away.


Lastly when the alarm is off and all looks normal, a distinct "snap", like a solenoid operating, is heard at the shift column area when the car is in Park and the brake pedal is pressed. This appears to be related to the brake light switch activating. No brake light bulbs are out. The snap is heard only in Park and when in any other gear it remains silent. But then when the "Engine Fault" alarm comes back on the mysterious snap sound also disappears just like the cruise control switch red light.


Can anyone shed some light on what this is all about? Is the car safe to drive to a shop to figure out this strange combination of symptoms? I'm stumped.


Don Elliott
Gig Harbor, WA
1997 XK8 coupe, #13926

 

It's very likely the brake switch. It has two microswitches. One turns the brake light on and the other turns the cruise control off when the pedal is depressed. The snap you hear is the gear lever lockout which allows you to shift out of park when the brake is depressed, also in the brake switch circuit.

 

Have you used a code reader to see if there are any set or pending OBDII codes? Disabling cruise control if the top of the list of actions on many codes so that would seem to indicate that there is one or more amiss.

Does your CEL/MIL come on when you turn the key to run without starting?

 

More testing shows that the "Engine Fault" alarm comes on after about 5000 engine revolutions (3 minutes of operation at 1500rpm, for example). This seems repeatable since it has now happened 4 times at that point today. Stopping the engine and allowing all systems to coast to a stop will clear the fault and set it up for a repeat. Is there a computer scan of systems that occurs after x number of revs perhaps?


To Test Point: Can you tell me what a CEL/MIL is please? An OBD scan is in order once I determine what the Engine Fault alarm means and I'm sure that damage is not imminent. AHAH I got it Check Engine Light = CEL and Malfunction Indicator Lights = MIL. All checks and display lights are normal when the engine starts up if the Engine Fault has cleared. When the alarm comes back on it is accompanied by no other alarm lights


To RJ237: The snap seems consistent with the lockout pawl to allow the lever to get out of Park, but when the Engine Fault is lit there is no snap yet I can get it out of Park easily. Still puzzlin'

 

Engine fault or restricted performance in yellow are not serious, but should be investigated. If red, that is serious, and probably should not drive.

 

What puzzles me is that "Restricted Performance" is a specific alarm message that is also an Amber alert but is accompanied by the Check Engine Light coming on. That is simply not happening. Instead the Check Engine light is off and we get "Engine Fault" (actual words) by itself. This term that is not at all described in the owner's manual. But I have to agree with RJ237 that amber alarms are advisory in nature to seek help.


If no one can actually give a complete answer to this puzzlement I'm going off to the dealer which is 50 miles away to check it out. Hope I make it.


1997 XK8 coupe

 

Here's the listing from the JTIS for a 97 give you a starting point but it does sound like a brake switch issue.

 

You can have the OBDII codes read at most AutoZone, Advanced Auto, Sears for free. I would first go locally to see what the codes are then post the codes (not what you are told they mean) and we will try to help.

Link to Codes http://jagrepair.com/images/AutoRepa...%201997-99.pdf

 

HAH SCORE! The information from Jamdmyers and Gus did the trick. There are two sets of failure codes that deal with the brake switch and the cruise control switch that are consistent with the display of the amber light, giving a message, but without tripping the check engine light. Tried a test this morning by shutting off the cruise control and then did a drive. No lights and no alarms. I now expect something odd about the cruise control perhaps more than the brake switch (but not 100% sure yet).


BUT with the warning lights out and the cruise control disabled, now I can confidently get this beastie in for service and verification of which codes are displayed without worrying about doing any damage.


It is a great service this Forum provides. Many thanks from me and the FERLCAT.

 

When I bought my car last year it had these same type of systems, except the engine fault would come on whether the cruise was on or not, I did take it to auto zone to get the codes read and there were none. I was going to take it to dealer for diags, but after talking to several people on here, I decided to change the brake switch first. that fixed the problem and it has been fine since. Switch prices vary very much, I found mine for $50, but when I searched later to have a backup, they were up around $125-200. Good luck.

 

According to the DTC Summaries that Gus furnished, the codes for the brake switch failure (P1571) and the codes for the cruise control issues (P0566-P0570) do not generate OBDII codes so I guess it is not surprising to find nothing on the code reader. I'll have time to deal with it in a month or so, but I'll let the Forum know what I find.

 

f you have the code reader and you don't get a P1111 then it's probably brake switch. To answer your question yes it cycles through tests then returns a P1111 if everything is OK. Try just turning the ignition on without starting it and see if you get the same error. It may have nothing to do with running for 5000RPMs

 

Thanks for clarifying that a code of P1111 means that all is OK. After running the car for most of the day with no alarms, it is becoming pretty clear that there is something about the cruise control system that is tripping the alarm. Depowering the cruise system with the switch on the console stopped the alarms, but activating the switch causes the alarm to recur after about 3 minutes running at 1500 rpm. The P0566-P0570 codes should be in the memory when I get close to a code reader, but OBDII codes are not displayed with these failures.


But I'm not going to ignore the brake switch either as that can do it too. By depowering the cruise control system and stopping the alarm I would think would point more to the cruise control switches. But I'll check both.


This Forum was crucial in figuring out this puzzle.

 

Well, well, well now, isn't this interesting? Continuing to poke at this issue has revealed that GordoCatCar has posted my exact symptoms way back on October 20, 2011 and the repair was to replace the brake switch that deactivates the cruise control when the brakes are touched. He too wondered why on earth that a failure of the brake switch would give an "Engine Fault" alarm.


Interestingly, looking at the brake switch is precisely what at least 3 others have suggested on this thread. So my focus has now shifted, (as was patiently previously suggested by several others ....eating some humble pie here), onto the blinkin' brake switch! AARGH.


I guess that's the benefit of owning a 19 year old car. Someone will always know where to kick it. More later in about 3 weeks.


Don

 

The problem is now resolved. Shoot up a flare! It was indeed the brake light switch that both lights the brake lights when the pedal is touched and cancels the cruise control as many have suggested. But it was a pricey little devil $324 at retail price.


So this failure gives an ENGINE FAULT display. Not terribly clear why that would be but there you are. Now onto other issues. Thanks to all for holding my hand here.