Emission Problems, help needed, please.

[bissell]

I have a 96 318is with 150k miles which recently failed its yearly emissions test.

I went to my local Bimmer specialist who attempted to speak to the car via the diagnostics port without any success.
They diagnosed a fault with the interface between their computer and the cars ECU and said that it required a new module costing $400. (reconditioned).
They said that they needed to observe the fuelling etc to find out why the emissions were high.
They also said that it would probably point to the catalyst being faulty and would require replacing.

I went for the cheaper option and fitted an aftermarket cat pipe and got the car retested.
The emissions failed again, lambda is okay but my mechanic mate tells me that the car appears to be over fuelling but to find out why its overfuelling he will need to speak to the car and guess what?, he cant communicate with the car because of a faulty interface.

Does anyone know how easy it is to replace this unit and the correct name for the replacement part?

somebody suggested its the DME? but i am not sure,

thanks in advance.

[grafhky52]

my question is how is the emissions machine can communicate but the shops diag equipment cant? the engine control unit is called the DME. I would take it somewhere else

[bissell]

Originally Posted by grafhky52

my question is how is the emissions machine can communicate but the shops diag equipment cant? the engine control unit is called the DME. I would take it somewhere else

The emissions machine doesnt communicate via the car ecu, it obtains its gas analysis via a probe which is placed in the exhaust.

The car failed the emissions test and was taken to my BMW specialist for help.
they attempted to communicate with the car but were unsuccessful stating that they were unable to do so due to a suspected faulty component.

would it be the DME that is faulty (the car runs fine if a little heavy on petrol) or is their another component between dme and the connector?

[whosyadadie01]

Originally Posted by bissell

The emissions machine doesnt communicate via the car ecu, it obtains its gas analysis via a probe which is placed in the exhaust.

The car failed the emissions test and was taken to my BMW specialist for help.
they attempted to communicate with the car but were unsuccessful stating that they were unable to do so due to a suspected faulty component.

would it be the DME that is faulty (the car runs fine if a little heavy on petrol) or is their another component between dme and the connector?

there is no probe going into the tailpipe to check emissions.
now they just hook it up to the computer in the car and it tells them everything.

[bissell]

Originally Posted by whosyadadie01

there is no probe going into the tailpipe to check emissions.
now they just hook it up to the computer in the car and it tells them everything.

Ahh, Maybe in the US you check emissions via the ecu, in the UK we use the probe method, sorry for the confusion.
As with everything we are a little technologically stunted in certain areas, good at fighting though!!!lol.

Any help would be much appreciated, if i cant communicate with the ecu, what part is broke? ecu or an interface?

[whosyadadie01]

yea we only use the probe method for cars made before 95. everything newer we hook up the computer to the car. and actually i think we are doing away with emissions after a certain age or i may be mistaken idk

[bissell]

any advice would be appreciated? how can i reduce emissions? is my DME faulty?

[whosyadadie01]

you may be onto something with that, i think your DME may be at fault but it is not a cheap part to start replacing and have that not be the problem

[Jeron]

Before replacing the DME I would start by checking contacts at the service port, the DME for bad solder joints and the wires between the two.

[bissell]

is that the socket that i plug the service reset tool in?

[Yurick]

Yes, that's the port.

[Jeron]

Yes.

There is also the OBD-II port by the drivers left knee (I'm not sure if 96 is OBD-I or II.) I'm not sure if the wiring is related but it wouldn't hurt to check the wiring there too.

[bissell]

thanks for the advice, i will begin by checking the diagnostic socket then the wiring between the diag socket and the dme.

In the meantime my car, (actually it belongs to my mrs), is going in to the workshop (a new one) where they are going to check the lambda sensor etc.
i'll keep you posted.

[whosyadadie01]

96 is OBD II