I was having a play about with my car at the weekend.Basicly the abs light was on and i was just checking connections on the abs ecu.I thought since i had the gove box out i would take the engine ecu out and have a look inside to see what chip was inside.

I disconnected the ecu and looked inside.I couldnt see a name on the chip.Anyway i plugged the engine ecu back in and the dam thing wouldnt start.I quickly checked and found the spark plugs werent firing and there was no power to the relay for the fuel pump.

To cut a long story short is it common for the wiring looms to nack up.Or do the ecu plug have to be fitted correctly.Im thinking i might have a brake in the wire somewhere cause i eventulay got the car running.

I had the ecu hagging out of its housing and it cut out again.I but the ecu back into its housing(where it sits) and the car started again.


Also does anyone have a diagram of the pins on the ecu so i know which wires are for which parts/sensors on the engine.


Thanks.

 

http://www.bigturbo.co.uk/

Click on the wiring tab and choose your ecu and you can buzz them all through with a multimeter to check continuity.

 

Also the abs light could be down to a dirty sensor.

You must remember that there wiring is going to be 20yrs old now and chances are its abit fragile so disturbing it could open a can of worms!

 

Not usually I have had mine out a few times, make sure the connector is firmly plugged into the ECU, and as said you can also test the wiring as well, the plug can only be fitted one way round.

Martin

 

Ive sorted my abs fella.Thanks though.

Also what are the purple relays for.I know the 2 yellow ones are for engine ecu n fuel pump.The green one is for the abs.




I also noticed there was a black relay where these relays are.Whats the black one for.

 

Wow that site is mint.Ive just had a quick look through and there is loads of info on it.

Thanks for that mate.

 

purple relays - ABS pump
black relay (and a grey timer relay which should also be there) - heated front screen

 

I thought the abs was the green relay.

 

the green relay is for the ABS ECU

 

sweet fella thanks for that.

 

Im just lookin on bigturbo.co.uk. At the top where the fuel pump n ecu relays are. Is that the permanent 12v supply or is it 12v ignition supply?

 

Both relays have a permanent and a switched feed to them, the latter is represented by the switch (Red bar facing upwards in that diagram) the ignition switch in this case, when you switch the ignition on the feed energises the relay hence tripping the "switch inside" hence power travels along to to the relay output and hence the rest of the circuit. So with a SPST relay you essentially have two circuits the relay itself (Live and earth) and the live output when the relay is tripped.

You will notice the ground connects to the ECU, this is how control of the fuel pump is obtained through switching the earth of the relay, the same applies to the ECU relay.

Martin

 

Thanks for that info mate.