Ecu Failure!

[taxidave]

My car has been off the road for over 3 weeks now so i am desperate for help!!

 

I had a gearbox & driveshaft fitted to my galaxy & when it was all ready to go

it was taken for a test drive to be told the car is guttless!! The garage has tried 4

different diag machines on the ecu but all that appears is connection failure.

 

Now without being able to read the codes & see what the fault is the garage can't get it

out of limp mode!! Any ideas??

 

They have checked all the wiring & also followed the wiring diagrams sent by Bosch but no success.

The only thing they haven't done is change the ecu!!

 

By the way the car starts fine & idles perfectly well. No warning lights appear on the dash.

If the ecu is at fault can they be repaired or is it a new one i have to get??

 

Thanks in advance

 

Dave

 

 

Ford Galaxy 1.9tdi(pd)

2004

[chrispb123456]

Turbo overboost will reset after an engine switch off and will drive normally till the next limp mode, this is usually sticking turbo vanes and/or turbo actuator, disconnected perished/collapsed vacuum hoses to and from N75 valve also defective N75

 

Underboost limp mode if due to charge pressure leak will not recover with switch off until fault is found, in other words limp mode automatically resets once faults have been repaired.

 

Power supply to diagnostic socket is fuse 32, 5amp although this is unlikely to be blown as it covers other items, have you physically looked at the socket to make sure no pins have been pushed out of the plug (just a chance).

[taxidave]

Thanks Chris,

 

Just spoke to the mechanic & there is power getting to the diag machines, they do power up but all they get is a connection error cannot read on the display screens!!

 

He has said once they can get can in & read the codes they can see what's going on.

[seatkid]

Its highly likely that in removing/refitting gearbox they pulled off one of the many small vacuum pipes that are part of the turbo boost control. They may have reconnected them incorrectly as well. Check the MAF sensor is connected as well as the piping / wiring to the boost pipework located immediately to the right of the engine block.

 

Doubt that the ecu is faulty. They probably dont have a compatible diagnostic tool.

Edited October 18, 2011 by seatkid

[taxidave]

Thanks Seatkid,

 

I'll pass this on. I have a VW technician coming out later today to look at it.

 

They have assured me they have checked everything!! I think a fresh pair of eyes on it

is the best way foward.

 

The Diagnostic kit they use i have actually seen both working on my car on previous occasions

so i know they work..hopefully the vw guy will bring his own piece of kit just in case.

[Mirez]

Ok first things first you are being told the car's gutless? Whats is feel like to YOU? If could be a long established issue (such as MAF failure) that you've gotten used to rather then a newly generated fault so you need to see what its like for yourself.

 

On the ECU side of it I've never seen one fail to talk, it would be a reasonably serious internal failure for that to happen as its a basic operation before all the software gets involved for it to link up correctly. Can they see any other module in the car? If they can't then its possible that K-Line is shorted, the K-=Line is the diagnostic bus that runs around the car - normally if floats at a voltage from 3v to 9v and is pulled to ground to get all the controllers into diagnostic mode - aftermarket radios and/or dodgy/faulty wiring have been known to feed the K-Line 12V and thus keep it from being pulled to ground.

 

If they can talk to other controllers then the K-Line must be ok and subsequently you can move on to looking at the ECU - specifically checking the state of the connector for corroded pins as whilst I've not seen a Gal suffer this problem its a semi-common thing on older Golf's and Bora's and leads to similar issues.

[taxidave]

Mirez, thanks for that.

 

I haven't had a chance to drive it since they have had the car. They seem to believe it is in limp mode as

soon as you start the car. Up until the car went in for the gearbox the only problem i had was the engine going into limp mode underload.

Like most people i would just turn the ignition on & off and it would run fine!

 

What i'll do is print this off and show it to my mechanic. I'm due to talk to him in a bit

to see what the the vw tech has said.

 

Thanks for the help and advice, if anyone else can shed any light on this it would be much appreciated.

 

Cheers

[taxidave]

Update:

 

Mirez, thank you for the info. I've just spoken to my guy and the VW tech has come up with the same:

 

K-=Line is the diagnostic bus

 

They have come to the conclusion that this is the only thing that could be causing the problem.

Even the VW Diag machine couldn't read the ecu!!!

 

Hopefully now this will get sorted, fingers crossed.

 

I'll post an update as & when i hear more.

 

To all that have replied thank you for your help & shedding much valued light on the situation.

 

Cheers Dave

[Mirez]

All they need to do is measure the voltage on the bus to a ground point - as said it should be anywhere from 3v to 9v (maybe even as high as 11v in rare cases) but should immediately drop to ground when the diag tool is connected - if it remains any higher then 1 or 2 volts then the controllers won't acknowledge the request for communications.

[taxidave]

Just had an update....yes still not sorted!!!

 

They have found the fault after endless amounts of time trying everything.

 

The ABS PUMP has shot....they disconnected it & plugged in the diagnostics & bingo access

allowed!!!

 

Now to find a pump