Dreaded engine failsafe mode
#1
Dreaded engine failsafe mode
Car wont start, although it did start 4 times on the trot and drove fine but then nothing.
I had no codes, so I checked fuel pressure, changed the crankshaft sensor and the spark plugs. I then got a P1229 code, so today I replaced the throttle body. I have no codes anymore but it is still in failsafe engine mode. Also put a teaspoon of oil down the barrels in case it had bore wash.
My question is ladies and gentlemen... should I now be looking at the ECU?
I thank you lol
I had no codes, so I checked fuel pressure, changed the crankshaft sensor and the spark plugs. I then got a P1229 code, so today I replaced the throttle body. I have no codes anymore but it is still in failsafe engine mode. Also put a teaspoon of oil down the barrels in case it had bore wash.
My question is ladies and gentlemen... should I now be looking at the ECU?
I thank you lol
#3
#4
Interesting
A tech I used to work next to had a similar issue. It was running when it came in, just for a service, then after it wouldn't start. Turned out the issue was inside the ECU, problem on ignition circuits.
I don't know about UK - but I would assume there is someone there who repairs ECU's. It's just a matter of taking it out and finding someone who can have a look.
Someone from UK here might be able to chime in - worth having it checked.
A tech I used to work next to had a similar issue. It was running when it came in, just for a service, then after it wouldn't start. Turned out the issue was inside the ECU, problem on ignition circuits.
I don't know about UK - but I would assume there is someone there who repairs ECU's. It's just a matter of taking it out and finding someone who can have a look.
Someone from UK here might be able to chime in - worth having it checked.
#6
What condition is your battery in ? Have you had it tested with a load on it ?
my battery was on its last legs, and I got the failsafe mode warning, wouldn't start, etc. all kinds of non functional on the dash, the CD player , the navigation screen, etc I replaced the battery and not a single hiccup so far. Thiese cars are very sensitive in regsrds to battery voltage and battery strength.
z
my battery was on its last legs, and I got the failsafe mode warning, wouldn't start, etc. all kinds of non functional on the dash, the CD player , the navigation screen, etc I replaced the battery and not a single hiccup so far. Thiese cars are very sensitive in regsrds to battery voltage and battery strength.
z
#7
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#9
It's not bore wash, as I said in my first post I oiled the barrels. It will randomly start and run completely normaly even if the engine failsafe pops up on the dash but if i turn it off with the engine failsafeon the dash it will not start again. The RAC guy put a new battery on it and it still wouldn't start. I also have a new battery on it now.
I checked all the loom conections, everything is clean. I'm thinking ECU?
I checked all the loom conections, everything is clean. I'm thinking ECU?
#10
1. Throttle motor disconnected
2. Throttle motor to ECM drive circuits short circuit or open circuit
3. Throttle motor failure
You've gone direct to (3) which should therefore also have eliminated (1). ECM faults are rare - harness and connector faults are much more common.
Still being in failsafe mode must have associated code(s) .....
Graham
#11
#13
He says he did. However by now it may be like that and it's worth looking (again).
If codes were cleared then also all the OBD monitors were cleared. Any that have not yet set again may be causing the car to be unable to flag codes. And also unable to set the monitor(s) - Catch-22.
(It's why clearing codes is not really a good idea.)
If codes were cleared then also all the OBD monitors were cleared. Any that have not yet set again may be causing the car to be unable to flag codes. And also unable to set the monitor(s) - Catch-22.
(It's why clearing codes is not really a good idea.)
#14
Have you checked the operation of the throttle body? If you pull the intake tube and put the ignition on (engine off), you should be able to see the butterfly move as you press the gas pedal.
From memory, there is a throttle body programming procedure. I have not had to deal with this, so I am unsure. You can always do the basic procedure: ignition on, engine off, slowly press the gas pedal through it's entire range, including the kickdown switch if you have one, then back off. Do this a few times to "teach" the ECU about the range of the pedal sensor. Free procedure, nothing to lose.
The proper path is to try and locate a Jaguar-aware scan tool and see if there is anything stored. For no-start conditions, I believe the ECU stores live data that can be read with OBD software.
Best of luck, keep us posted.
From memory, there is a throttle body programming procedure. I have not had to deal with this, so I am unsure. You can always do the basic procedure: ignition on, engine off, slowly press the gas pedal through it's entire range, including the kickdown switch if you have one, then back off. Do this a few times to "teach" the ECU about the range of the pedal sensor. Free procedure, nothing to lose.
The proper path is to try and locate a Jaguar-aware scan tool and see if there is anything stored. For no-start conditions, I believe the ECU stores live data that can be read with OBD software.
Best of luck, keep us posted.
#15
Thanks guys. The thing is, I have already done everything that you have all said. I also did the proper procedure for a new throttle body (pedal slowly down etc) I’ve spent hours on here reading other people’s posts. Starting off with the small things. It started the other day completely normally l, I tookk it for a 20 min drive no problems at all. I switched it off and left it to heat soak for a while but when I went to start it, low and behold failsafe engine mode !
#16
Given the age of the car and the things you have already tried, I think it would be sensible to have a look at the ECU to check for blown capacitors. First though you might want to do what fmertz has suggested and see if you can read any live data that might give you a clue when it is failing to start.
#18
#19
I am not sure at the moment because I am experiencing the same issue. I am at the point that I feel it is the ECM but want to do additional testing. With my situation I could turn the key on for about 20 seconds and then start it and it would start. The attached video will show you how I am not getting spark on the start action but after a few seconds on the second start it starts up.
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#20
Relay connections.
Remove and clean all under the hood(bonnet) connections.
One Day on our 2003 XK8 car was perfect. Stopped to eat, car started and went into limp mode.
Checked codes when limped home. Throttle body. Finally found relay had popped out of its socket???
Dont know why, but it did.
Might be a similar relay problem for you.
One Day on our 2003 XK8 car was perfect. Stopped to eat, car started and went into limp mode.
Checked codes when limped home. Throttle body. Finally found relay had popped out of its socket???
Dont know why, but it did.
Might be a similar relay problem for you.