check engine warning light

mark ovenden · Sep 19, 2009

I have a 300tdi auto R reg, the engine revs itself up when i come to a stop and the check engine warning light comes on,if i gently touch the accelerator pedal the engine will go back to tick over and the light goes out if i let go of the pedal it revs up again and the light comes back on, sometimes i have to put my foot under the pedal and try to pull it up some more ,even though it is roight up, this will then cure the problem. i only have to move the pedal millimetres to stop the egine reving like mad , any ideas please...the accelerator to pump is something called fly by wire i think as there is no cable??

Paul D · Sep 19, 2009

Sounds like the throttle potentiometer. Sorry, mine doesn't have fly-by-wire, but it's a commonish problem. Check (search for) Rave ...

discobill · Sep 20, 2009

:bump2: Sorry to bump this one but... I've just got back from Bargain Booze and my 'Check Engine' caption illuminated twice. Just on and off briefly.
It's the first time it's happened in the year or so I've had the Disco and the handbook ain't no help.
All I've done with it today is tweek the timing a tad and it feels better but I'm sure that has sod all to do with the light.
Anyway, I'm not overly concerned by it, just curious. Any ideas ?

eightinavee · Sep 20, 2009

discobill said:
:bump2: Sorry to bump this one but... I've just got back from Bargain Booze and my 'Check Engine' caption illuminated twice. Just on and off briefly.
It's the first time it's happened in the year or so I've had the Disco and the handbook ain't no help.
All I've done with it today is tweek the timing a tad and it feels better but I'm sure that has sod all to do with the light.
Anyway, I'm not overly concerned by it, just curious. Any ideas ?

It does,where you have altered the timing the injector pump can no longer control the point of injection by pump advance to where it wants to from info given by the crank position sensor/needle lift sensor.
In other words put your timing back right and the light wont come on.
Mr Ovenden,yours is more of a problem - best to get it on Testbook to see what faults are logged and then view all the live data readings to confirm.The Bosch EDC system is very reliable but repairs,esp throttle pots tend to be expensive,best to only repair the right bits.

discobill · Sep 20, 2009

Cheers Eight' I'll see how it goes tomorrow. I was only tweeking it as after I'd changed the cam belt I put it back to factory setting and since then it's been a bit laboured on start. I've advanced it 2mm and if it's the same tomorrow I'll back it off a bit.
Thanks for your reply... Bill

mark ovenden · Sep 21, 2009

My landie has allready been on test book and no fault was found,typically it did not play up when it was being tested.Thanks for your advise..

eightinavee · Sep 21, 2009

mark ovenden said:
My landie has allready been on test book and no fault was found,typically it did not play up when it was being tested.Thanks for your advise..

Then you have two options,first you can wait till it faults again and get it back on Testbook,or find a decent specialist to scope all the engine sensors,in particular the throttle pot,crank sensor and needle lift sensor.The scope will pick up faults that the Testbook live data displays may not be accurate enough to detect.
If it faults again there will be faults logged - the Bosch EDC system is more than happy to log them and they are usually very accurate considering the age of the system.Was the person using the Testbook skilled in its use,like any diagnostic tool it is only as good as the person using it.

mark ovenden · Sep 22, 2009

Thanks for that, i took it to a landrover dealer,all they did was plug in a small calculator sized thing.
It plays up all the time now, i have found that if i touch the wiring harness at the back of the engine near where the pedals are on the inside it makes it stop reving sometimes.
May be i have a dodgy connection or broken wire some where ,im going to take your advise and get it tested again at a different place.
Hopefully they will find the fault.
Cheers.

eightinavee · Sep 22, 2009

You could have a dodgy connector for the crank sensor then,the ecu will run off the needle lift sensor if the crank signal is corrupted,but its not so accurate - the ecu sets a high idle speed to prevent stalling.

check engine warning light

mark ovenden

New Member

Paul D

Old, nackered 'n broke, but the Landy is fine . :)

discobill

Active Member

eightinavee

Well-Known Member

discobill

Active Member

mark ovenden

New Member

eightinavee

Well-Known Member

mark ovenden

New Member

eightinavee

Well-Known Member

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