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MG MGF Technical - Cost to replace ECU?

I’ve been informed that the ECU on my 1998 MGF VVC needs to be replaced as the radiator fan is kicking in too quickly; I have been told they’ve undertaken the usual diagnostics and can confirm that the ecu needs replacing.

I’ve been quoted 255 plus VAT for parts and 135 plus VAT for labour (3 hours), is this about right?

The temp gauge has always hovered at just below the half way mark, I’ve just had HGF failure (repaired two weeks ago) so am not sure whether the failing ECU could have contributed to it, if so I’m keen to get it repaired

Thanks
M Stoneham

sounds like sh*te to me.

the first step I would make is to go to Maplin, buy some contact cleaner(£2) and unplug the brown sensor, spray a liberal amount in the connector and plug and then insert and unplug a few times, then do the same for the connector on the ECU. If this doesn't cure things then change the brown sensor for a new one (£20)

If still no joy find yourself an auto electrician instead of a garage.

The fitting price seems about right, about 12 bolts, one connector and a reprogram of the ECU to match the alarm. The ECU cost seems low - is this a refurb?


The fan kicking in early is a sign that the ECU is reading a higher resistance than it ought to. if by "early" they mean "always" then the ecu has lost the temp sensor or thinks that the readings are too far out of band, the "fan on" condition is a failsafe, the engine will be overfueling as well, so MPG should be down, but this would not lead to HGF
Will Munns

thanks, the failing ECU diagnosis was provided by an auto electrican and the price quoted was for a new ECU.

The fan always kicks in early and I'm assuming they would have carried out checks on the sensor (wrong assumption?_)

Are there any long term problems with not relacing the ecu for a few months?
cheers
M Stoneham

As Will says the sensor failing or having dirty contacts is a very well known problem - the ECU failing isn't.

I would have though that if the ECU was failing you might get other problems besides the fan running early - but then modern electronics are funny things!!

Personally I would go along with Wills suggestions first then if that does not work............
Ted Newman

Whilst I do not have an MGF or TF I enjoy browsing this board simply to learn from those more experienced.
However this thread as my curiosity,

What do you mean by kicking in early. Yes I know you mean IYO it starts too early but what are the symptoms.

Does it run when you are traveling at a reasonable speed? or do you think it starts early when in traffic?

I ask this simply to perhaps suggest that it may actually be working correctly
Bob (robert) Chairman north lincs and district pigeon fanciers society

I'm picking it up tommorow so will monitor the symptoms more closely and will let you know.

As a serious novice to repairs (never taken of the engine bay cover) how easy is it to locate and unplug the sensor to spray it?

Thanks for your advice....
M Stoneham

Finding the plug is easy... but long winded!

The brown sensor is on the coolant outlet from the engine.

Looking at the engine it is on the head, on the gearbox end next to the exhaust manifold. Unfortunatly you will need to remove the engine cover to get at it, this is a 30 mins with a ratchet screwdriver job

1: unclip and fold the roof forwards, secure with a strap (I sue a piece of wire trapped in the windscreen frame)
2: lift out the rear parcel shelf carpet
3: undo all the 10mm bolts
4: lift slightly and slide the parcel shelf forwards
5: hinge up the back and pull out - be careful with fingers, the bottom of the bulkhead cover is sharp

6: locate the sensor (brown, there should be a black or blue sensor for the gauge there as well)
7: on the long side there is a spring clip - PRESS this and wiggle the plug, it should come free

fitting is the process in reverse but be careful not to over tighten the 10mm bolts or they will strip their threads.

The ECU is visiable thru the inspection hole with the boot open, it is on the opposite side to the water tank.
Will Munns

I had a similar problem. In my car 'Fan coming on too early' meant within a minute of starting the engine, which considering the 12.5litres of coolant is too soon! But IIRC you can get to the sensor by unclipping the grille under the bootlid (but I could so easily be mistaken!). Anyway, as I was unware of contact cleaner (TM) I just took it off, wiped it and put it back and its worked ever since. Once you know what you're looking for its a very simple job. Also happened to a friends F, he picked up a replacement sensor from a scrappy K series Rover which also sorted the problem.
Pete D

I need to get my Caterpiller pricing out but I am amazed by the low price quoted on the VVC ECU. £255 plus VAT seems a good £500 less than I would have expected to pay in the UK for a new ECU. I agree with Ted's view on the ECU. I cannot believe you would have just one problem.

Based on what is presented in this thread I just do not believe your Auto Electrician. It is either not a new ECU or it is a small part like a sensor and he is trying to rip you off
Julian

This is with images on what Will reffered to
http://www.mgfcar.de/coolant_sensor_change/index.html
(I changed the sensor cause of similar _wrong_ failure prediction. Finally it was the poor connection only.)

Very unusual for an ECU failure, indeed, and I wonder how the specialist has found this ?

GTR206 / GTR313 / MEK100060 is the sensor p/n
More on the subject @
http://homepage.swissonline.ch/TomsSeven/Main/CTS_ECU_Logic.htm
(VVC, so different kick in/off temp)
and at my site
http://www.mgfcar.de/sensor/index.htm




Dieter

Thanks all for your advice, I'm looking to purchase the sensor from www.mgocaccessories.co.uk, can anyone confirm whether this is the correct part?

Temperature sender for fan (brown) Its 10.95 inc vat. Located in the Electrics section....

The site doesn't mention a coolant sensor although this part sounds right....

Apologies for the basic questions...

Unfortunately no helpful pictures attached.

cheers
M Stoneham

Temp sensor "brown" is what you are looking for, but be sure to get the right year for your car - there are at least two different types
Will Munns

>Temperature sender for fan (brown) Its 10.95 inc vat.

That's the right one for your 1998 MGF.

HTH
Dieter
PS. bookmark http://www.mgfcar.de/epc
Dieter

This thread was discussed between 16/10/2007 and 20/10/2007

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