[mowog73]

The ECU Alarm, also known as the 5AS unit, is in the passenger compartment in the centre console, mounted to the bottom of the heater control. You can access it by taking off the two finisher panels that have the footwell lights. The ECU alarm/5AS unit is held in place by two plastic 10mm nuts.

 

[digcot 65]

The ECU Alarm, also known as the 5AS unit, is in the passenger compartment in the centre console, mounted to the bottom of the heater control. You can access it by taking off the two finisher panels that have the footwell lights. The ECU alarm/5AS unit is held in place by two plastic 10mm nuts.

Ive sorted te fuel pump now,so it runs with ign on .The start circuit t is the main problem ,this is why the previous owner sold it Checking the voltages ,I have 12 v on fuse 19,when the ignition is off I thought this should only be there,when ign key is turned to start,or am I missing something. Also I have 12 volts on both sides of the start relay coil, when ign is turne to start which means the one side of the coil isnt going to earth otherwise the coil would energise with 12 volts on the other contact.

I cant understand why there is 12 volts on fuse 19 but nothing on coil contact marked A until ign is turned to start .On the circuit ,it shows a connection between fuse 19 and point A

 

[Roverlike]

Coil contact marked A behaves as it should. However regarding fuse 19, are you sure you are measuring correct fuse?

 

[digcot 65]

Coil contact marked A behaves as it should. However regarding fuse 19, are you sure you are measuring correct fuse?

Thanks will check .Unfortunately after my headlong crash into a brick wall ,just before Christmas I had to go to the doctors yesterday ,due to neck pain I was sent to our local hospital ,who then sent me to the main one,where I had a neck scan Fortunately,I hadnt any breaks,but I was told to rest for a couple of weeks as I had caused severe bruising to the neck area So my wife has banned me,from the garage for a while I have enough to check on the circuits to keep me busy Again thanks for your help Im sure Ill get the MG right with your help Len

 

[digcot 65]

Thanks will check .Unfortunately after my headlong crash into a brick wall ,just before Christmas I had to go to the doctors yesterday ,due to neck pain I was sent to our local hospital ,who then sent me to the main one,where I had a neck scan Fortunately,I hadnt any breaks,but I was told to rest for a couple of weeks as I had caused severe bruising to the neck area So my wife has banned me,from the garage for a while I have enough to check on the circuits to keep me busy Again thanks for your help Im sure Ill get the MG right with your help Len

Just krept into the garage ,whil my wife is having a shower Which is fuse 19 as I must me making a mistake I can understand,why when there is 12 volts on on side of the start relay coil it doesn`t energise The other side going to the alarm doesn`t make sense as it seem to return to a 12 v supply Len
PS There is one fuse missing

 

[Roverlike]

Pictures you are showing is fusebox under the bonnet.

Sattelite fusebox is the one attached to fusebox under steering wheel. Fuse number 19 is in the sattelite fusebox.

 

[digcot 65]

Pictures you are showing is fusebox under the bonnet.

Sattelite fusebox is the one attached to fusebox under steering wheel. Fuse number 19 is in the sattelite fusebox.

Whoops you live and learn Len

 

[digcot 65]

Whoops you live and learn Len

Does anyone have an idea,why when the 12 volts starting voltage is applied the the starter relay coils,it fails to energise I cant see ,why the return goes to another 12 v supply .Len

 

[digcot 65]

Does anyone have an idea,why when the 12 volts starting voltage is applied the the starter relay coils,it fails to energise I cant see ,why the return goes to another 12 v supply .Len

I haven`t got back to the MG since my fall,as its still very sore. I`ve been looking at the wiring and the return for the starter relay,goes to the main ECU .So its pointing to that being the problem I know if I replace it,I have to get the exact same one but what else would I have to replace I seem to remember some years ago,when I replaced one on an MX 5 I had , the key fob had to be changed with one that matched the replaced ECU Can anyone advise please Len

 

[digcot 65]

I haven`t got back to the MG since my fall,as its still very sore. I`ve been looking at the wiring and the return for the starter relay,goes to the main ECU .So its pointing to that being the problem I know if I replace it,I have to get the exact same one but what else would I have to replace I seem to remember some years ago,when I replaced one on an MX 5 I had , the key fob had to be changed with one that matched the replaced ECU Can anyone advise please Len
[/QUOT Forgot to add,how do I tell of my 1999 MG F is a V V C engine or not

 

[Roverlike]

If you are changing engine ECU it needs to be paired with your alarm system. Otherwise it will not work.

Pairing can be done with T4 Testbook diagnostic software and machine or with software like PScan: www.pscan.uk

 

[Julian Foulger]

Rev counter, vin number, VVC control mechanism on the right side of the engine and various other ways (incl with older MGF's the letters 'VVC' on the inlet plenum). Google search is a powerful tool to get answers.

 

[digcot 65]

Rev counter, vin number, VVC control mechanism on the right side of the engine and various other ways (incl with older MGF's the letters 'VVC' on the inlet plenum). Google search is a powerful tool to get answers.

Thanks, its pointing to the ECU .Shame as the car is in excellent condition re body work and interior andhood . Also it looks as though the starter is new , along withe brake master cyl and rear brake disks However I just dont feel well enough to finish along with the bad fall I had over Christmas Len

 

[digcot 65]

Thanks, its pointing to the ECU .Shame as the car is in excellent condition re body work and interior andhood . Also it looks as though the starter is new , along withe brake master cyl and rear brake disks However I just dont feel well enough to finish along with the bad fall I had over Christmas Len

I see there are some ECUs along with the alarm module,and a key fob for sale on Ebay I`ll have to see how I feel in the future as to whether I should buy this package The forum have been very helpful in answering questions I imagine,if I fitted one of these package ECU ALARM BOX AND KEY FOB that no mapping would be required I fitted an ECU into a Mazda MX5 I had some years .But I had to reconnect every wire,as damp had got into my original sockets .It came with a key fob and worked great after wards Len

 

[Roverlike]

Correct, no pairing needed if you buy complete package, but you will need to swap all of them then.

 

[digcot 65]

Correct, no pairing needed if you buy complete package, but you will need to swap all of them then.

Morning,there are several ECU kits for MG Fs on Ebay I just have to check the numbers on mine ,to make sure they are the correct ones They all have a key fob with them,but shouldn`t there be a chip to go into the key itself. I remember when I did the same on a Mazda MX5 I had to have the matching chip,to go into the key itself so the car would recognise it and a new key fob for the doors . Len

 

[Roverlike]

No chip in case of MG F. You need MEMS 2J engine ECU, 5AS alarm ECU with 2 connectors and working fobs.

 

[digcot 65]

No chip in case of MG F. You need MEMS 2J engine ECU, 5AS alarm ECU with 2 connectors and working fobs.

No chip in case of MG F. You need MEMS 2J engine ECU, 5AS alarm ECU with 2 connectors and working fobs.
[/Managed to remove ECU but tight considering screws go into plastic sockets Mine seems to be unusual as it has only one socket and an airline pipe. One on Ebay ,but numbers different ,however since it is all three items in a set can I use that one Mine is in photo FS MKC 104111 2507 4098.One on Ebay has different numbers Len

 

[Julian Foulger]

The attachments above are not pictures of a MEMS 2J ECU (which is only for a VVC). In addition, a "J MEMS has both black and red connectors.

 

[Roverlike]

So your car does not have VVC engine.
Which engine ECU is yours?

MKC 103730 or MKC 104111?

In accordance to this site: MGF and MG TF Engine electrics and sensors engine ECU MKC 103730 is superceeded by engine ECU 104111, so it would be reasonably correct to say you could swap these two engine ECUs.