1999 VW Lupo ECU Change
Discussion
Help !
The Background. . . . . 1999 petrol Lupo Sport 100BHP model.
My 165,000 mile lupo is not running very well at all when cold, The temp sensor has been changed, compression test done which shows 200 psi across all cylinders. When it is warm it runs fine, but it has failed its MOT on Emissions, probably the only VW that has
!
I have tried to read any faults via the OBD port without success, as have two other guys with different readers. the port seems open but none of the readers connect with the ECU.
The suggestion is that the ECU might be playing up, and as this is easy to get to, I have removed it as the part number was needed by VW to quote for a replacement or other sources of course However, is it a straight forward plug and play swap ? others have mentioned the imobiliser which I am not sure my car has.
The door locks have played up for a while which is a common Lupo issue, so I don't tend to lock it, which I guess activates the imobiliser, so with a new unit and not locking the doors should I be ok ?
Anyone got any experience on this ?
The Background. . . . . 1999 petrol Lupo Sport 100BHP model.
My 165,000 mile lupo is not running very well at all when cold, The temp sensor has been changed, compression test done which shows 200 psi across all cylinders. When it is warm it runs fine, but it has failed its MOT on Emissions, probably the only VW that has
!I have tried to read any faults via the OBD port without success, as have two other guys with different readers. the port seems open but none of the readers connect with the ECU.
The suggestion is that the ECU might be playing up, and as this is easy to get to, I have removed it as the part number was needed by VW to quote for a replacement or other sources of course
However, is it a straight forward plug and play swap ? others have mentioned the imobiliser which I am not sure my car has. The door locks have played up for a while which is a common Lupo issue, so I don't tend to lock it, which I guess activates the imobiliser, so with a new unit and not locking the doors should I be ok ?
Anyone got any experience on this ?
Firstly, you say fails on emissions, that covers a multitude of sins, more information is definitely needed to stand a chance of helping .
You don't say that the "eml" is on, so if there are no codes the reader won't help, it is 1999, so pre-ebd & any information on a reader may well be limited anyway (no experience of this era VW specifically)
Have you tried a simple oil/filter/air filer/plug change?
It can significantly help emissions readings.
You don't say that the "eml" is on, so if there are no codes the reader won't help, it is 1999, so pre-ebd & any information on a reader may well be limited anyway (no experience of this era VW specifically)
Have you tried a simple oil/filter/air filer/plug change?
It can significantly help emissions readings.
guys thanks for the replies
plugs, oil and air where all changed couple of thousand miles back. so I believe these are all good. I did check the gaps and all appears to be in order, bar the plugs being black which to me is over fuelling. The EML light has never come on, not sure if this is a bulb issue or a more significant.
My previous Lupo had a throttle body change when erratic running was the problem, and as this car runs so smoothly I don't think it is that.
I don't have the test results here with me at work, but from memory on the emission it only fails at idle, not general running. But I will hook these out and report back.
plugs, oil and air where all changed couple of thousand miles back. so I believe these are all good. I did check the gaps and all appears to be in order, bar the plugs being black which to me is over fuelling. The EML light has never come on, not sure if this is a bulb issue or a more significant.
My previous Lupo had a throttle body change when erratic running was the problem, and as this car runs so smoothly I don't think it is that.
I don't have the test results here with me at work, but from memory on the emission it only fails at idle, not general running. But I will hook these out and report back.
Rather than throw £££££££££ at it with a new ecu it might be cheaper to book it in to a garage to take a look at it. I have seen so many times before hundreds if not thousands of pounds spent trying to fix a problem that was something of nothing. Does the engine management light come on when you switch the ignition on before the engine starts?
cheers for the replies
I have asked on club lupo. . .in short it was a suggestion on there to get the ECU tested as no one on the forums can understand why the OBD port to ECU seems to be down.
the temp sensor, was a green variety so replaced with the same from VW
the engine code is a ACK I believe according to VW parts guy checking against the chassis no.
The EML doesn't come on, I have owned the car for 4 years and it has never come on, perhaps a sneaky PO took the bulb out, that said I have never had any issues and it has always passed its MOT up until now.
I am favouring the 'get the ECU tested' anyone got any recommendations in this regard ? car is in Surrey.
I have asked on club lupo. . .in short it was a suggestion on there to get the ECU tested as no one on the forums can understand why the OBD port to ECU seems to be down.
the temp sensor, was a green variety so replaced with the same from VW
the engine code is a ACK I believe according to VW parts guy checking against the chassis no.
The EML doesn't come on, I have owned the car for 4 years and it has never come on, perhaps a sneaky PO took the bulb out, that said I have never had any issues and it has always passed its MOT up until now.
I am favouring the 'get the ECU tested' anyone got any recommendations in this regard ? car is in Surrey.
Take a step back, you are jumping the gun here.
Once you have access to a diagnostic tool that you know is for your car, should that tool not work, you first need to get it to work and knowing that the tool is good the problem can only be a wiring fault or ECU fault.
Check the wiring from the diagnostic plug to the ECU and check that all the other wiring at the diagnostic plug is as should be, you will need a wiring diagram to do this.
Once the wiring is checked and ok or made ok, should the diagnostic tool still not work, there is obviously something wrong with the ECU and it will be worth your while to have it tested or replace it with a donor ECU
Once the ECU is communicating with the diagnostic tool you may or may not find a problem with a component or engine wiring but at least you will be heading in the right direction
Once you have access to a diagnostic tool that you know is for your car, should that tool not work, you first need to get it to work and knowing that the tool is good the problem can only be a wiring fault or ECU fault.
Check the wiring from the diagnostic plug to the ECU and check that all the other wiring at the diagnostic plug is as should be, you will need a wiring diagram to do this.
Once the wiring is checked and ok or made ok, should the diagnostic tool still not work, there is obviously something wrong with the ECU and it will be worth your while to have it tested or replace it with a donor ECU
Once the ECU is communicating with the diagnostic tool you may or may not find a problem with a component or engine wiring but at least you will be heading in the right direction
aka_kerrly said:
benters said:
the engine code is a ACK I believe according to VW parts guy checking against the chassis no.
.
Your engine code will be AFK - in less someone has fitted a 2.8 Passat V6.......
I still think the problem lies with the K-line wire which is essential for VAGCOM to work.
No the have a temp gauge sender for the gauge and a water temp sensor for the ecu, the ecu fuels according to what that sensor says, have look on flea bay one is green one is blue, hence ecu fueling rich as it doesn't know any different, I have changed many in lots of motors, don't forget to get the plugs cleaned/replaced as they could well be fouled now, and not great for the cat and sensors either if it has one, depends how far it's run.
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