ECU

[helderteixeira]

Question: is it possible to read the ECU without the immobilizer using the normal 3 pin plug? Or can only be done using a db9 connection? Directly to the ECU.

Edited by helderteixeira on Wednesday 6th July 11:03

[nawarne]

Hmmm, short answer - don't know!

However, wouldn't you want to see the sensor inputs into the ECU - Lambda, water temp, throttle position, barometric pressure sensor etc, etc, are all reading sensibly....You need the ignition 'ON', therefore the immobiliser disabled to see these values.

But, I'm no computing expert...Maybe call one of the servicing garages?

Nick

[EvoOlli]

You have either the 9pin connection on the ECU (the older blue ones) or you have the 3pin connector on the cable on the newer ones (silver). But anyway, the ECU needs to be powered on and this is handled by the immobilizer.

[helderteixeira]

Double checked, there's nothing coming out from the 3 pin plug. The reason that i need now is because I'm changing the throttle cable and adjusting the idle. do i really need to do the reset from the ECU for the new position ?

[EvoOlli]

Do you use the correct cable ? Which software do you use ? Are you sure, that your cable/computer/software setup works ? Why do you say, there's nothing coming out ? Why do you ask for the immobilizer ?



You will find the diagnostic port signals on the Black Plug of the MBE ECU:
Pin 1B Serial Comm Ground
Pin 1C Serial Comm TX
Pin 2C Serial Comm RX

[helderteixeira]

I'm using the correct cable, and i have tried all the combinations for the pin layout. I'm saying there was nothing coming out "data" from the black plug, because connected to the pc using the "terminal, there was nothing received by the pc" I'm an IT Engineer, so 100% that the laptop port is working tested with a different device" so the question for the immobilizer if it's not present, does the black plug works without the immobilizer?

[EvoOlli]

The ECU needs to be powered on....don't know the circumstances of your car, but in a normal car the ECU gets its power from the immobilizer. And without power there's no communication, even on the black plug.

A Terminalprogram won't certainly help you, because you have to send special codes to the ECU to get a response.

Which Diagnosis Software do you use ? Did you try my version ?

[helderteixeira]

The previous owner bypassed the immobilizer, i don't have it installed.
But the Ecu is power on i think, because have all the info available on the dashboard or is the blue Ecu just for extracting the info to the pc?
The terminal program was just to see if the Ecu was sending anything to the port, you would see strange characters on the terminal screen... so that's why I'm saying that the black plug is "dead" but as you say "because you have to send special codes to the ECU to get a response". The version that I'm using isNew Diagnostic Software (.zip | 954Kb)(yellow car background)) from: "http://www.thetvrsite.com/cerbera/ecu-diagnostic-software"

[EvoOlli]

Give my Software a try:

www.pistonheads.com/gassing/topic.asp?h=0&f=15...

[helderteixeira]

i will try tomorrow, and let you know.

[Basil Brush]

helderteixeira said:

The previous owner bypassed the immobilizer, i don't have it installed.
But the Ecu is power on i think, because have all the info available on the dashboard or is the blue Ecu just for extracting the info to the pc?
The terminal program was just to see if the Ecu was sending anything to the port, you would see strange characters on the terminal screen... so that's why I'm saying that the black plug is "dead" but as you say "because you have to send special codes to the ECU to get a response". The version that I'm using isNew Diagnostic Software (.zip | 954Kb)(yellow car background)) from: "http://www.thetvrsite.com/cerbera/ecu-diagnostic-software"

The blue ecu is the engine management ecu, the software just reads the data from it.

If the immobiliser has been bypassed (as has mine as it failed) then it just means that the ecu powers up as soon as the ignition key is turned to second click, ie when the dash and fuel pump kick in, so you should be able to connect to it.

What message are you getting from the tvr software when you try to connect?

Have a read through this if you haven't already. There is a link to a thread with the pin assignments for the 3 pin plug.

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Edited by Basil Brush on Saturday 9th July 08:41

[helderteixeira]

Hi Basil,

this is my pinout, is this correct ?


Still no joy...

Evo

If i connect the db9 plug to my pc, and connect 2-White;3-Red directly, your software show's some numbers.

[chimyellow]

I realise that this is not a direct answer to your question but I use a USB-Serial Lead to connect to my ECU.
The RS part numbers (http://uk.rs-online.com) that I use (some of which you have already) are below.
I have used this cable on a few Tuscans and used the same RS232 cable for the basis of a lead to connect to the ECU in a Cerbera.


USB to RS232 Lead (no ends) - 687-7828
Plug Shell - 475-353 (comes as a pack of 10)
Plug Pins - 468-541 (comes as a pack of 10)

The pin layout is (going by the numbers on the Plug Shell)
Pin RS232 Cable Colour
1 Orange (TXD)
2 Yellow (RXD)
3 Black

I use EvoOlli's software and find it brilliant.
I have had it working perfectly on Windows XP, 8 and 10 (including Windows 10 64bit).
The only thing that I use the TVR software for it to look at the adaptive map graphs as this is not available on EvoOlli's (future feature request???), however I don't often look this anyway.

The TVR software does not work on 64bit machines and is a bit of a pain to use as it only supports COM1 and 2.

Edited by chimyellow on Monday 11th July 23:29