cwrm4

On post #78, robbed666 shows a snipped R9 on the ecufix board, with a note that it improves the serial signal...could this help?

robbed666

YOU DO NOT WANT A NULL MODEM CABLE!!!

You want a V24 straight through wired cable. Female to Female. This might be hard to find. Just get a fully wired 9 pin serial extension cable, and a 9 pin Female to Female 'gender changer' also fully wired pin to pin.

Null Modem Pin Connetion: (The one you dont want!)
is wired as below:

FG (Frame Ground) 1 - X - 1 FG
TD (Transmit Data) 2 - 3 RD
RD (Receive Data) 3 - 2 TD
RTS (Request To Send) 7 - 8 CTS
CTS (Clear To Send) 8 - 7 RTS
SG (Signal Ground) 5 - 5 SG
DSR (Data Set Ready) 6 - 4 DTR
DTR (Data Terminal Ready) 4 - 6 DSR

Laurence Gibbs

lets see if i can help here. First off if your interface does not echo back you have a pc to interface problem. Not an interface problem which is believe it or not good news. First of try this. Get the info of the net for which pins do what in your lead. Specifically which pin nos represent rx and tx. On a straight through 9way to 9way i think there pins 2 and 3. go to hyperterminal and set up a connection with just the lead connected to the pc. place a jumper across pins 2 and 3 and type anything on the keyboard. You should see an echo back. If you dont two possibilities first you got the wrong cable or pins the second more likely your com/ serial port has been hijacked by other software. Go back through the com port set up etc to cure this. Only when you have an echo back through the bare lead not attached to the interface but with rx tx connected can you be certain the pc is sending the data corrrectly. one sure of this try hyperterm with the interface attached and again check for echo. don't jumper rx tx in this case. Hope this helps.
Just to recap IT MUST BE A STRAIGHT THROUGH CABLE the above test is for use with a straight through cable. The interface will not work otherwise.

LeRoux Strydom

Thanks everyone for chiming in. I will get a serial extension cable and a m-f gender change plug tomorrow, which I believe is the easiest way to get a straight-through wired cable.

Here is a good link explaining the difference in DTE and DCE serial connections:
http://www.taltech.com/support/pins.html

Le Roux

pncarrerars

Just to confirm that I have got around to testing my Andy Whittaker interface that I bought as a spare. It worked straight away with the L line led cut out. (thanks Laurence & robbed666)

For those unsure about the connections here is the bare 19 way socket & here it is with the wires inserted

Pete

LeRoux Strydom

Pete

It is interesting to note that the 19-pin plug on my car (1990 C2) has many more pins wired to the plug than your car does. What gives?

jimq

Maybe a stupid question but when running the test is the car started or not. What position does the key need to be in the ignition if not? Darn I guess I need to be online early thursday to get an interface!

pncarrerars

Hi LeRoux

Yes your year car has more pins wired according to the diagrams but you should still only need 0v, 12v, K & L. Mine is an RS so maybe this is another weight saving that has not been documented!

jimq, Ign on otherwise the ecu etc wont talk. Engine running if you want all live data.

Pete

LeRoux Strydom

SUCCESS!!

A big thanks to everyone who helped me to get the comms going with my car's DME (pncarrerars, dougb, laurence gibbs, robbed666)

I have the following points to mention to anyone else who wants to get this going:
1. I had the wrong serial cable (female-female) that obviously was not wired straight through. I ended up using a regular serial extension cable (female into the pc, male on the other end) with a male-female gender change plug that goes into the interface board.
2. Andy Whittaker's interface works fine as reported by others. I removed the two LED's and did not test the comms with them connected. Not needed imho.
3. I used an old desktop that I hauled out to the garage with a good old-fashioned RS232 serial port, running W2000.
4. A laptop with a USB-serial converter did not work at all, most likely because the scantool software and DME use odd baudrates not supported by the USB-serial converter. I will experiment with a PCMCIA-serial card as I would like to monitor the DME inputs while the wife drives.
5. The 19-pin plug is not an issue at all, imo. I just shoved the bare wires from the interface board into the appropriate socket holes, and it worked. I may wire a more convenient connecter into the back of the 19-pin socket permanently to facilitate future diagnostics work.

Below are some screenshots of my work tonight. I have the following observations:
1. The Motronic connection happens very quickly. My car reported no fault codes. Actual values displayed are taken immediately after a cold start. I will run the car tomorrow and take some measurements when warmed up.
2. The actuator tests (test outputs) did not mean much to me, as they are numbered rather than described. Can someone post the meaning of the different tests? DougB perhaps?
3. Some of the diagnostics are also meaningless. For instance, I have no idea what IAC Count, MAP, NTC1/2, Channel 5, FQS and MAP Sensor are. Can someone in the know please enlighten me?
4. A 1990 C2 (right-hand drive) will not connect to the ABS/traction control module nor to the SRS airbag module (the car is not equipped with an airbag).
5. The connection to the climate control unit takes more time to be established, and as reported by others, will initially show fault codes since the CCU wakes up more slowly than the DME. Clearing the faults and re-testing shows no faults codes remaining.

I also have the following suggestions to improve the user friendliness of the scantool3 software, in case DougB will be so kind to spend more time on it :
1. The idle/CO adaptation will be very useful if implemented.
2. User-selectable COM port rather than hard-coded COM1 usage will help to iron out connection problems and may assist laptop usage.
3. If the actuator output tests could be made repeatable for individual systems, this may help troubleshooting. The tests now simply run sequentially, and the entire test regime has to be repeated even though you may only want to test injector 4, for example. Better descriptors for the various tests will also help a lot.
4. Including metric units for temperatures etc. may help those of not in the UK/USA. Not a big issue, however.

Many thanks again to everyone who made this possible at such low cost.

Sorry for the long post, but you can tell I am excited!

Le Roux

pncarrerars

Hi,
Glad you got it working!

>>3. If the actuator output tests could be made repeatable for individual systems, this may help troubleshooting. The tests now simply run sequentially, and the entire test regime has to be repeated even though you may only want to test injector 4, for example. Better descriptors for the various tests will also help a lot.
Usually this is how the ecu works, even modern VWs diagnotics work like this. As with all car diagnostics the workshop manual is needed to understand the data & tests. The Porsche manual deals with the "Hammer" but the tests & data are essentially the same. I believe that Doug wrote this software for his own use & then kindly let us have a copy hence the lack of features such as com port selection.

>>4. A 1990 C2 (right-hand drive) will not connect to the ABS/traction control module
I warned about this in an earlier post. Only C4 ABS is diagnostic capable!

>>4. Including metric units for temperatures etc. may help those of not in the UK/USA. Not a big issue, however.
Look at scantool.cfg, you can do what you like!

Hope that helps a little.

Pete

MPB993

Hello everybody,

this looks like a very useful piece of kit but does anyone know whether this will work with a 1995 993 with obd1? Knowing that the obd connector is different but still has K & L lines.

BR, Mark.

loot87

The "back in stock on 4/27" message is now gone and still listed as sold out. Andy has still not responded to my repeated questions on shipping to the US. I may be hitting up DigiKey soon....

Patrick964

Hey guys,

I am currently gathering parts to build Gregg K.'s interface. I have 10 Sipex 3222EC that are being shipped to me. Let me know if you need one. They are not available thru digi-key. It is an 18 pin so some of the pins numbers differ from the schematic.

Patrick

jimq

Are you going to build and sell the whole interface or just the boards? I sure would like a put together one!

Patrick964

Not selling. I'm just doing one for myself. Just thought since I have extra chips, maybe someone is in need of one.