Important! : how to test an ecu

21st July 2011, 18:54

hi all, before i send my ecu off for unlocking i want to test it to see if there is power going to it (it don't start, imoblier light flashing ect)

so just wondering how i would test to see if i had power to the ecu. i.e wich wires to i tap into witht the multimeter rct

thanks in advance

21st July 2011, 18:57

What ecu?

21st July 2011, 19:33

the ecu i pm'ed you about unlocking but never got a reply lol

someone posted about they tested theirs and it got me thinking has it really locked itself or is it just not getting power and disabling the imobliser

it s 3 plug furio sagem s2000 ecu btw

21st July 2011, 20:09

Is the ecu light on? Also what color is the relay inder the ecu

22nd July 2011, 11:42

i bellive it is a big red one. the imobliser light is flashing and i get no sound of the fuel pump priming + no spark either.

hmmm thinking back i may have almsot disconnected that big red relay well took the pin thing out but then thought i'll leave it cause i don't know what it does lol

could this be my problem?

22nd July 2011, 11:53

Sounds more like the ecu has no power to me

22nd July 2011, 13:44

Quote:

Originally Posted by ryanmt

Sounds more like the ecu has no power to me

Me too. Sounds exactly the same symptoms as when my VTS wouldnt start. Turned out one of the wires supplying power to the engine bay had been nipped. Replaced the damaged section of wire and all was fine.

22nd July 2011, 19:58

that sounds good could you tell me how to test it for power then?

no good with electrics without instruction lol but am good with mechanicals hate electrics so don't want to try something and blow the ecu up or something

(sorry if it sounds ponsy lol)

thanks

22nd July 2011, 21:27

Fuel pump priming is that the 'brrrrrr' noise when I turn the ignition without starting? I always wait for that sound to stop before I start..

Sorry off topic.

23rd July 2011, 00:44

Quote:

Originally Posted by f13sta

that sounds good could you tell me how to test it for power then?

no good with electrics without instruction lol but am good with mechanicals hate electrics so don't want to try something and blow the ecu up or something

(sorry if it sounds ponsy lol)

thanks

take some pics of the relay below the ecu, and post up a picture of the label on your ecu.

23rd July 2011, 15:19

Quote:

Originally Posted by RDKells

Fuel pump priming is that the 'brrrrrr' noise when I turn the ignition without starting? I always wait for that sound to stop before I start..

Sorry off topic.

hahah bit random there mate lol

Quote:

Originally Posted by ryanmt

take some pics of the relay below the ecu, and post up a picture of the label on your ecu.

ok will do today

23rd July 2011, 15:36

pictures as requested

23rd July 2011, 15:36

25th July 2011, 17:56

up got the photos that were requested

25th July 2011, 18:18

Hi,

Here your wiring diagram,

Thanks
Daniel

25th July 2011, 20:10

thanks mate but i'm more confused looking at your diagram than at the haynes speaking of haynes it seems its totally different to what i've got going into the realy. i assume this brown realy is the main fuel injection realy.

i did some value finding and i'll write down what i got on the different wires.

relay number wire colour voltage
1 pink 1.94 v
2 N/A
3 blue 0.00 v
4 beige 0.00v
5 white 0.00v
6 grey 0.00 v
7 grey 1.74 v
8 blue 0.00v
9 white 1.99
10 green 0.00v
11 blue 0.00v
12 white 0.00v
13 red 0.00v
14 brown 0.00v
15 blue 0.00v

this is with the ignition turned on i also did a continuity test aswell and got these values

relay number wire colour value continuity Y/N
1 pink 0v N
2 N/A
3 blue 3.3 Y
4 beige 4.8 Y
5 white 4.8 Y
6 grey 4.8 Y
7 grey 0 N
8 blue 3.2 Y
9 white 0 N
10 green 0 N
11 blue 3.3 Y
12 white 4.8
13 red 4.8 Y
14 brown 4.8 Y
15 blue 4.8 Y

i hope that this is not too confusing but this is how i wrote them down on my paper pad lol

25th July 2011, 20:18

Hi mate,

yeah reading wiring diagrams can be confusing

From the big relay you should have:

At pin 3,8,11 and 15 - Power (+12v) at all time (ignition on or off)

With ignition ON you should have power at 4,5,6,12,13 and 14

check out those pins first and let us know what you find,

Thanks
Daniel

25th July 2011, 20:24

hahah i took too long to type the above.

this were also with the relay in place not removed i just poked into the wire lol
so i should have power if i remove the relay? i did this aswell but can't remember if i go power or not.

just a thought would a wrongly plugged sensor be the cause of this?

25th July 2011, 20:31

Hi,

With the relay removed you still should have power at 3,8,11 and 15, the power to this pins come from 2 fuses, but because if the measurements that you are doing are correct I don't think it is a fuse, instead it seems to be a wiring problem where there is high resistance in the wiring, make sure when you measuring those pins the multimeter black lead is properly connected to the negative terminal of the battery.

To make sure you go a good ground on the black lead just connect the red one to the positive of the battery and you should read around 12 volt, do that first and then measure up those 3,8,11 and 15 pins and let me know what you found,

Daniel

26th July 2011, 19:04

hi dan took the readings on the pins 3,8,11,15

readings as follows
pin number volts reaistance continuity
3 - 0 V - .001 - 00.5
8 - 0 V - .001 - 00.5
11 - 0 V - .001 - 00.5
15 - 0 V - .001 - 00.5

all seem consistant but also low lol i assume i have a wiring issue?

kyle.

26th July 2011, 19:38

Ok, that actually looks better now, where exactly did you check continuity from?

Have you checked the fuses?

Thanks.

26th July 2011, 20:09

hi.

i just flicked the miltimeter to continuity and checked it like i checked the voltage. i.e

black wire to battery of multimeter and red wire of multimeter to the pin i've checked the one that is in the engine bay fuse box that seems to be ok . is there another one?

looking back at the readings i didn't get any voltage at the pins but i did get continuity so does it sound like a fuse.

26th July 2011, 20:15

Hi,

OK forget the continuity checks for the minute as you can not do it that way, problem seems rather estrange that you have no power at all in any of the 4 pins as there are two circuits with two different fuses, so what I would do next is check all the fuses, one by one all of them, and let's hope you find two blown, let us know.

26th July 2011, 20:23

ok mate i'll check all the ones in the engine bay and car then

26th July 2011, 20:43

checked the fuses mate and all seem to be ok not blown or anything, could a wrongly plugged sensor be the cause of this?

26th July 2011, 20:51

No surprise there, didn't think 2 fuses were going to be gone at the same time quite unprobable.

No, a sensor won't do that.

I just need to make sure you testing it correctly, thus I guess you are measuring with the multimeter in VOLTS and red lead into wiring of relay and the black lead is connected to negative battery, is this right? Thus if while doing this if you connect red lead of multimeter to battery positive what do you read in multimeter?

27th July 2011, 17:24

right i put the multimeter to 20 ont he volts with the line and dot symbol. connect black to -'ve of battery when connecting red to battery get around 12volts

and yes red wire connecting to the relay pins.
going to re-charge the car battery just incase overnight so it'll be fully charged.

27th July 2011, 18:01

Ok, you measuring it correct, but I still can't believe there is not power in none of them.
I will check another wiring diagram to see exactly what fuse number are for those 4 wires and I let you know, but I won't be able to do this until tomorrow.

You can try tracing back the wiring but that may be a hard work.

Thanks.

27th July 2011, 18:34

yeh i don't get it either was runnng before i took engine out witout any problems. thanks for your help thus far mate

30th July 2011, 01:14

Hi,

Sorry I have been very busy so I haven't had time to check out for more specific wiring diagrams, but if the problem happened after the engine change, have a good look that you haven,t left any main plug disconnected, as well make sure you didn't put a positive lead by mistake into the negative of the battery (I've seen this done).

After this checks with your multimeter check power at the fuses in the engine bay and inside the car, do this with the ignition on, and you should have power in at least 80% of them, let me know what you find when you've done this,

Thanks

30th July 2011, 17:07

hi mate thanks for all your help i managed to get it running today. all it were was i put a live that should have gone to starter motor to the earth point (the like is something to do with the altinator according to the haynes diagram)

30th July 2011, 17:20

Ah that's good, thought something strange like that had to be :-)

30th July 2011, 18:15

yeh thank god its running then engine light is on tho but thats a pre occuring problem,

but many thanks for your help it has helped me alot i'mslightly more clued up on electrics now

thanks mate.

3rd April 2012, 08:37

Sory to drag up an old thread, I am having an almost identical problem since someone changed the starter motor - key light is flashing and there is little to no power at all at the relay.

I can see there is what looks like an earth loop loose by the starter motor that hasnt been connected. Should this be bridged with the live feed rather than to earth? Anyone got a pic of how the starter should be connected correctly?

3rd April 2012, 12:36

Confirmed, with the earth-looking loop attached to the same terminal as the live cable on the starter motor, the immobiliser light goes out with the key and the relay has 12v power on a number of pins.

With it connected to the wrong part of the starter, or not connected at all, there is no 12v signal to the relay, and with the ignition on your readings are around 2.5v.

Now i need the engine management light to go out and the damn thing to start!

3rd April 2012, 12:52

Quote:

Originally Posted by drlvp

Confirmed, with the earth-looking loop attached to the same terminal as the live cable on the starter motor, the immobiliser light goes out with the key and the relay has 12v power on a number of pins.

With it connected to the wrong part of the starter, or not connected at all, there is no 12v signal to the relay, and with the ignition on your readings are around 2.5v.

Now i need the engine management light to go out and the damn thing to start!

Am I understanding this correctly: you connected an earth to a +ve supply and now your electrics work??

3rd April 2012, 20:45

Quote:

Originally Posted by Gabbastard

Am I understanding this correctly: you connected an earth to a +ve supply and now your electrics work??

it's not an earth all the earth wires on a saxo are a green+yellow wire.

but to anyone that knows even a little about cars, a plain black wire is an earth but not on french shite