Hi all, my MY00 turbo was serviced today and I mentioned to the mechanic the surging/hesitation problem that occurs mainly when the car is cold but sometimes slightly occurs when warm. After the service he told me that there were two error codes showing, one for the O2 sensor and another for the coolant sensor. He wanted to replace both these but with labor costs it'll come to around £280. Now, could these sensors realy be the problem and just because an error code was showing does it mean its knackered and needs replacing. If the advice is to have them replaced is it possible to do myself or is special kit needed?
Thanks for any advice.

FC

 

You need in my opinion to reset the ecu if they didn't to clear the fault code history and then drive it checking every so often for fault codes.. if the engine check light has not been on then chances are the fault codes were old..

If it is hessitating when cold and there is a couple of fault codes then worth adding extra earthing as the earths corrode lots..
negative battery terminal to block or inlet manifold, negative batt to suspension turret etc..

Look here for ecu reset info and error codes..

Hope that helps

JGM

 

A faulty O2 sensor can cause this problem. They are easy to change yourself, all you will need is a 21mm spanner. You can get cheaper universal O2 sensors from parts factors but you will then have to chop and join wires.
Although an O2 sensor is not listed in a service book, it is classed as a servicable item, with a life exp of only 30,000 miles before loosing effiency.

 

Changing the coolant temp sensor may also make a difference, as this is used when the car is cold (obviously), but also when the engine is under high load.

The sensor is a bit awkward to get to, since it's stuck on top of the engine block under the inlet manifold and load of pipes! However, the sensor itself is less than £30 new, so a diy change may be worth while.

A failing sensor will not always give a CEL, but may store as a fault on the ECU.

As above, reset the ECU, and check for faults on a regular basis - if the ECU is telling you it has found a fault, chances are it has....

 

Thanks for the replies.
The check engine light goes out straight away when I start up, do the codes show up here if they are still current? Should this light stay on?
Looking at the link posted by JGM there is a procedure for checking the fault codes but it's not very clear to me. Where is this thing located where you need to connect jumpers and what do you use to connect them?
Thanks for any further advice

FC

 

Gad why can't I find a haynes manual for this car, didn't they print one?

 

No strangly Haynes never did one..

The car is pretty straight foreward to work on when you get used to it..

If the coolant sensor is gone you normally get the fans on all the time and it runs lumpy as the ecu doesn't know whether the car is hot or cold so does both just in case.

Connector are under the steering column.

Run your hand from steering wheel height adjuster down the dash until it drops off the bottom.. then dive upwards and you will find a set of wires. amoungst them will be a yellow connector (select monitor port) and I think it is 3 black connectors and two green. They are sometimes taped back to the other wire with blue tape. Two black ones fit together and two green ones..
I forget which way around it is.. I think the two black do the error codes.. connect two black only, turn off immobiliser and switch on ignition, do not start.. the check light should flash a code as explained on that website, if nothing happens then turn off ignition as I got the black and green the wrong way around.. disconnect black and connect two greens, take immob off and turn on igition again.. if you get a steady once a second roughly flash then this is the okay code and you have no errors, otherwise you have an error... see the website for diagnosis or come back on here.

The light should go out when you start the engine is normal use of the car..

try that and see what you get

JGM

 

Theres isn't a Haynes workshop manual for the Scoob.

Recently had similar problems with my MY00. Juddering / hesitation at lower revs. Scoob dealer replaced Lambda sensor and car is now much better - Still a bit rough from cold but fine once warmed up. Sensor was £90 ish + VAT I think but they charged less than a tenner labour to diagnose / replace I'd get this sorted soon or it may cost you a lot more long term.

Cheers,

Ian.

 

Thanks for the post JGM I'll have a root around under the column tomorrow. The cars fan runs normaly so the coolant sensor problem may be a red herring.
Ian, that price for a sensor was about what I've been quoted but they wanted 2hrs labour to do the work £116 + VAT, hence I may buy a sensor and have a go fitting it myself.
One of the tips to eliminate this surging problem seems to be to swap the AE802 ECU for an older one. I've just been offered a AE801 but the board is in a green labelled AE802 case, I'm gonna start a new topic to see if anyone can clarify for me whether I'm getting the correct board.
Cheers
FC

 

FC,

Have a nosey around this thread if you haven't already. Surging/hesitation whilst cold is a normal occurance as the ECU waits for the o2 sensor to come up to temperature.

Going by what Bob Rawle said about disconnecting the O2 sensor completely, I would expect a failed sensor to actually improve on the problem.

Stefan

 

Thanks ozzy I have read that thread. Hence I'm trying to source an older ECU as apparently they didn't suffer this problem.
Cheers
FC

 

Two hours labour My dealer diagnosed the problem within 10 minutes including test drive. When I asked them to fit the sensor it took less than 5 minutes. Just looked at bill £8.80 labour £98.53 Sensor + VAT.

You will find an earlier ECU a big improvment. I've got an AE800 in mine.

Cheers,

Ian.

 

Look under http://www.ecutek.co.uk - Tuning - OEM ECU comparison for ECU info.

 

Hey it took me 2 months to convince my Dealer that my O2 sensor was faulty (as proven by John Banks and DeltaDash).

Looks like these days you need to diagnose faults yourself

Are you positive an AE800 will cure this? I was under the impression the AE800, AE801 and AE802 all suffer from this; just the older ones to a lesser extent. My AE801 certainlyu does, but can't comment on the AE800.

My old Prodrive (PPP) ECU did the same too.

Stefan

 

Well I managed to find the black and green connectors and performed the ECU re-set ok. While doing this the only flashing done by the CEL was a steady on and off which I believe means no errors. I'll drive it for a bit tonight to see if it's made a difference.
I've an AE801 ECU coming soon so when I fit that I'll also post as to whether it's made a difference.
Cheers all
FC