ECU Diagnosis

Jun 14, 2005
920
2
Northants.
Hi All,

When plugged into diagnosis equipment will the ECU (Ibiza GTi) produce a fault code that is specific to water ingress?.

If not how do I identify if water has effected the ECU?

Many thanks

DC
 
Last edited:
Jun 14, 2005
920
2
Northants.
I'd like to remove the ECU for further inspection - but read that it then needs recoding with the Immobilser when re-installed!

How do you do this? Will it require a speciallist?

What is the process for removing the ECU and what other problems could be encountered?

Many thanks

DC
 
Jun 14, 2005
920
2
Northants.
Went out and tried starting it tonight and it started first time and settled down to a normal idle!. I let it warm up then took it for a drive up the street and back which was fine through first but when in second it became very stuttery and hesitant. When stationary if you applied the revs smoothly it was fine but blipping the throttle cuased it to stutter, cough and judder and at one point die. I was able to start it again but only by playing with the throttle which again was very lumpy with some unreasuring noises.

I dont feel right starting again so I've left it and also disconected the battery!

I'am getteing really fed up with it now!

I'd be very gratefull for your opinions!
 

cordobabrendy

FOOORRREEE!
Aug 24, 2001
7,642
1
belfast
the ecu wont give a water type error more of random sporadic errors ie abs, idle etc the only way to check fr water is to take it out and look inside, the car is out of warranty so opening it wont really matter as long as you do it indoors and try to prevent static.
 
Jun 14, 2005
920
2
Northants.
the ecu wont give a water type error more of random sporadic errors ie abs, idle etc the only way to check fr water is to take it out and look inside, the car is out of warranty so opening it wont really matter as long as you do it indoors and try to prevent static.

Cheers for the reply!

May sound daft but how do you best prevent static? If removed doesn't it then cause issues with the immobiliser!

Cheers

DC
 
Jun 14, 2005
920
2
Northants.
shouldnt think so, removing the ecu has the same effect as removing the battery.


The haynes manual says that the ECU is coded and will require "adapting" to the Immobilliser, otherwise it may not function correctly when the multi plug is reconnected.

Apperently "specialist equipment' is required which I presume means VAGcom or simliar

DC
 

traumapat

Leon Cupra IHI
Jul 24, 2005
5,925
4
sunny sussex
might be wrong here but isnt the immobiliser part of the ecu circuitry?

what makes you think its the ecu getting wet that causes these problems?
have you checked other things like the throttle body?

does it only do this from a cold engine?
 
Jun 14, 2005
920
2
Northants.
might be wrong here but isnt the immobiliser part of the ecu circuitry?

what makes you think its the ecu getting wet that causes these problems?
have you checked other things like the throttle body?

does it only do this from a cold engine?

I thought the same with the ECU but on searching its not very conclusive!

After a Holiday on the coast which before and during the car worked perfectly - I gave the car a hosing! This included the lower parts of the bulkhead in the engine bay and the back of the engine (cold of course!!) but I may have accidently allowed too much into the scuttle area!!!.
During washing I never got water anywhere near the Coil, Plugs, Leads and Dizzy Cap/Rotar (replaced recently) but there may have been indirect splashing of the Throttle Body and ther area around the air filter.
 

traumapat

Leon Cupra IHI
Jul 24, 2005
5,925
4
sunny sussex
no expert here but id have thought water inside the ecu would bring up several earthing faults??

im wondering if the maf has been affected?

the throttle body bit isnt related to the soak its just over time they can get full of muck and cause jerky operations.

perhaps give a respected vag tuner a ring. last time jabbasport had my car they swopped ecus with ease and i think most tuners will be used to physically playing with them. so they proberly have the knowledge you need.

tell us how you get on mate
 
Jun 14, 2005
920
2
Northants.
Cheers traumapat!

If the MAF can be affected by water I have a new spare I could put on - but I'am not shure how this would cause the starting problems I've had which the last time sounded a bit mechanical!! - it seamed like the timing was out!!

I wonder if somthing is slipping but again how this can be caused by water?

What a nightmare!!!

The difficulty is I can't take the car to anyone to assess - they would have to come to the car. Anyone got a recomendation for the South Leicestershire area!

Cheers

DC
 

traumapat

Leon Cupra IHI
Jul 24, 2005
5,925
4
sunny sussex
you need to find someone on here with vagcom near you who can check the ecu for fault codes. that can be done without firing her up. that will give you a clue hopefully to whats wrong. theres no way water has physically got into the air filter is there?

i reckon the waters shorting a contact or somthings been knocked whilst cleaning. mafs dont need excuses to break but id think that if waters gotten into the connector itll mess the circuit and make your car pooey.

id try the vagcom route first. it`ll give you somthing to work with