106 replies to this topic

[unknown4u]

BETTER TITLE: THIS IS A SOLUTION FOR THE AIRBAGLIGHT!




Hi,

This is my second item on 968 forums. Maybe some guys know me from the .net or Stuttgart. I'm sorry to see what is going to happen to that site of 968 at the moment.
The last couple of months I did have a triggerd airbagwarninglight. It was triggerd by a stupid mistake from me. After that I read almost every topic of it on the web..

Every time there was a solution of cutting the wires at the control unit from the airbag. And that, for me, was a cheap solution!.

At that time I would try to do it the right way. Either by buying a Hammer or what else?

One day I found out that the 964 has the same problem.
After reading the topics at R.L. for the famous scantool designed and made by Doug Boyce for the Porsche 964. I would try to make it work for the 968 as well. Reading the complete topics cost me a lot of time. But I became very enthousiast the more I red. The procedure I write is based on many replies from them.

I first have complete examined the electrical scheme’s from our beloved type the 968.
I discovered that the 968 was build to talk by the OBD-1, with the Iso 9141-1 protocol to the Famous Bosch Hammer. Many evenings passed with my oscilloscope and voltmeter in the car to check it out.
 hammer.GIF   5.41KB   18 downloads

The Bosch Hammer can do more functions than this software
But much more than you can do with only your voltmeter.

First of all, The regards for the software are for doug.boyce@hummingbird.com
I’ve never met him or has received a return mail from the guy but he has given a free copy of his software for the 964 guys. He also said it worked on to his car. I discovered it works on my 1992 as well. But if you will try what I did. It is for your own risk!

I hope this will start a great topic and as you will provide your help We all can have a great diagnostic tool with all the fault codes etc to keep them running!.

I'm sorry that I cant post pictures because I only have them in BMP format and not the GIF extensions what is needed. So I can not make it visible to you guys.

Ritchie
Owner of a '92 Coupe with the M030 option.


What is OBD and the Iso protocol?

ISO 9141 is the OBDII spec defining the data format and uses the RS232 serial
data protocol which provides ASCII characters. A standard PC with an RS232
port can talk to the K & L lines of an OBDII port or the 968 port.
No external level or electronic circuits are required. "

The 968 diagnostics is based around ISO 9141-1. ISO 9141-2 is the updated ODBII protocol. A level converter IS requires as the logic/voltage levels on the K & L lines are different than rs-232.

"The problem with reading the 968 data is developing the proper command codes
and interpreting the data. This is a form of ODBI which was not standardized as
is OBDII for all '96 and later cars."

The 968 protocol belongs to a group of older "keyword" protocols that were used in many European autos. It's very simalar to VAG's KW 71 protocol. In fact, you can reconfigure the 968 software to connect to an older VW that uses the KW 71 protocol and many of the basic functions will work. The 964's "command codes" were discovered by reverse engineering the Motronic ECU software. And as I found out they are the same for the 968.

"The electronic circuits generally available only "strip out" the ASCII characters
from the data stream which can be used by non-PC type scanners to access
the K & L data. The signal level of the K & L lines is 0 to 5 volts."

Here is some data from the K and L line from the original repair manual from Porsche 968

 k_en_l.GIF   10.31KB   33 downloads

968 Diagnostic tool FAQ

Q1. where do I get the software?
Ans . Download the software from http://members.rennl...s/scantool3.zip or look within the thread NEW UPDATED VERSION 4 with engine adaption below http://dedeharter.co...l/scantool4.zip This one must be checked for the 968 because it has 993 features!.

Q2 Who wrote the software?
Ans . This project owes it’s thanks to Doug Boyce for writing the software and providing it for free!

Q3 Where do I get the interface?
Ans. Currently there are about 3 ways to obtain an interface. www.ecufix.com (Andy Witthaker) sells a fully built opto-isolator type design compatible with iso 9141-1 . Today 12 jan 2008 Andy no longer sells the interface anymore.  intface.GIF   9.43KB   56 downloads

I cut off the inside of led D4 on the interface board. This must be done because the led has an interfearence with the signal from the K line. If you do not cut them is is hard to connect to the 968. Or almost impossible.
Be sure the jumper on the interface board is on the two outside pins, not the two inside pins.


You could also build the interface supplied in the scantool3 software zip.
ELM type interfaces will not work with this software. I tried but it won’t work out.

Q4 Does Doug Boyce know that it will work for a 968?
Ans. I don’t think so. I’d once sent him an email but got no response.

Q5 what else is required to get the diagnostic tool working?
Ans. A computer / laptop running windows 2000 or Xp (haven’t tried it yet), will not run under win 95 or as I discovered win 98 second edition either. A 9way dtype m/f straight through cable (and possibly a gender changer) .

Q6 Where can I buy the 19way plug?
Ans. Currently John Speake of www.jdsporsche.com is the only known supplier of these from the other forum.. He ask 95 euro's. That is a lot. He completly made it by cnc it. I prefer it without the 19 way plug.
Though it may be possible to purchase from Porsche? But don’t think so because can’t find it in PET.

 19pin.GIF   7.87KB   31 downloads

Q7 Where can I buy the 9 way d type lead. ?
Ans. This can be purchased through any computer supplies shop.

Q8 what about using a laptop with a usb adapter?
Ans. There are some issues with this as not all adapters work. Please read the whole thread for more info.

Q9 my interface won’t connect using my laptop and the 9way cable combo?
Ans. The ecufix opto design has an issue when running with the led’s connected. It’s adviced to cut these out. You will find that it will connect ok after that. This is less of an issue when using a desktop computer.

Q10 Problems finding the Comport 1.
Ans. As delivered scantool uses COM PORT 1.
Initially I was unable to get the connection (Unable to find COM1 error message). Found a comment in one of the threads that pointed to a scantool.ini file. Could not find the file so I ended up creating one under C:\Windows and adding the following two lines to it:

[Comm Settings]
port=COM1

Q11 How to test COM PORT 1?
Ans. Test the COM 1 port and interface pcb with a PC application like HyperTerminal.
Available free on the internet. To setup HyperTerminal to test COM 1:

Open HyperTerminal, File,
New Connection,
Name= Interface test,
OK, Connect using= COM 1, OK,
Restore Defaults,
OK. You'll know you've configured HyperTerminal
correctly by shorting RS232 pins 2 & 3 together, typing & seeing the type on the monitor.
Remove the short and the display shows no typing. When this works, plug interface pcb
into COM port 1.

9 Pin Connector on a DTE device (PC connection)
Male RS232 DB9

Pin Direction of signal:
1 Carrier Detect (CD) (from DCE) Incoming signal from a modem
2 Received Data (RD) Incoming Data from a DCE
3 Transmitted Data (TD) Outgoing Data to a DCE
4 Data Terminal Ready (DTR) Outgoing handshaking signal
5 Signal Ground Common reference voltage
6 Data Set Ready (DSR) Incoming handshaking signal
7 Request To Send (RTS) Outgoing flow control signal
8 Clear To Send (CTS) Incoming flow control signal
9 Ring Indicator (RI) (from DCE) Incoming signal from a modem


Q12 What do I connect to the cars diagnostic port?
Ans . Your interface should have four leads K, L, 12v and 0v (ground) . These are connected to K to pin 8 , L to pin 7 , 12v to pin 12 and 0v (gnd) to pin 10. You will find the diagnostic port socket is numbered. There is also a diagram within the main thread.


 19pin2.GIF   34.69KB   24 downloads

Q11 So put simply how do I get this thing working???
Ans Download the software and install it. Obtain an interface (ecufix being my choice) Connect the 9 way dtype lead from the computer to the interface and connect the K, L, 12v , and 0v to the 19 way diagnostic socket on the car. Run the software and switch on the ignition. The software should say connected. If not don’t panic . Check through the main thread for useful help, also check back to Q9.


Q12. The software can for the 964: For the 968 I have tried not everything because I would like to share directly my knowledge with other 968 fans to help me.

• Read/Clear fault codes for the Motronic ECU, air bag, climate control and PDAS.
• Run actuator tests for Motronic. This is a test that cycles the different actuators such as the resonance flap and fuel injectors. During the test you’re expected to listen for the actuators clicking on and off.
• Display values from the Motronic’s analog inputs such as the voltage from the air flow meter and temp sensors.
• Display the state of the Motronic’s idle and wide open throttle switches.
• Display Motronic’s actual operating parameters such as rpm and load. Practically all of the operating parameters are available but I believe the version of the software that’s currently out there has a limited list of parameters.
• Display Motrinic’s high/low range AFR trim values along with a live O2 sensor signal.
• Display the state of the PDAS traction control switch.

What it can not do:
• Bleed the PDAS system.
• Operate the transverse and longitudinal locks.
• Display ‘knock counts.’ This isn’t really a diagnostics feature. It’s implemented separately with a +12 volt pulse signal.


Q13 Can it reset the airbag warning light?
Ans. Yes it can. It was the first thing I tried. Because of that I invested many evenings!.

The next code was shown by my 968.

Signal implausible
Fault code 30 It means that after I had disconnect the instrument cluster and turning on the ignition without instruments You’ll get this code.
Now I’ve cleared it is gone and the lights are out. Yes and form me this topic is already finished by doing that by my selves. Al the other possibilities are extra goodies!

Fault code 21 means disconnected steeringwheel airbag

Other codes are:

Ign. circuits
Frt.sensor left
Frt.sensor.right
Ign.pill.circ.1 (driver side)
Ign.pill.circ.2 (passenger side)
Ign.pill.circ.3 (passenger side)
Airbag warning light.

In topic
http://www.968forums...?showtopic=3881
You can read more about this codes.

Q14 How can I connect to the ALARM?
Ans. The ALARM, connects without the key switched on, usually. All others require
ignition to be on. The INPUTS, ACTUAL VALUES and the other items for the
accessories do not work. The CLEAR and REFRESH for faults do function.
We have to research this for the 968. It was possible to connect to the alarm. I do have a fault but it was not shown.

Q15.My CCU quits operating when connected but reports fault codes. The ABS when connected causes the dash lamp to light as well as reporting faults.
We have to research this for the 968.

Q16. Witch program is necessary to change the scantool.cfg?
Ans. You can use notepad.

Q17 Witch baudrate use the motronic? We have to research this for the 968.
Ans. I think it will use the 8800 baud. It is changeable in the scantool.cfg.

Q18 What are al the positions from the 19 way plug?

 tek19p.GIF   12.82KB   9 downloads

1. Airbag Gong Relay
2. Unused
3. Unused
4. Unused
5. OBC On/Off
6. Unused
7. L
8. K
9. Unused
10. Ground
11. Unused
12. Battery +VE
13. Ignition Power
14. Pin 6 of the DME, Rev Counter
15. Pin 22 of the DME, Check Engine Control On DME
16. Unused
17. Unused
18. Unused
19. Pin 21 of the DME, Knocking

Q20. Another COM PORT issue why it could not work.
Ans. I thought the serial port not working, but in fact it was simply disabled in the BIOS!

Q21. Where can I get the connectors for the 19 way plug?
Ans. The pin contacts are 2.5mm, part #962971-1 from AMP. AMP solder type pin contacts (Tyco Electronics AMP product code 745-6) soldered to circuit board leads (http://www.altex.com/)

Q22. What are the costs?
Ans. For the interface and some stuff you will get it to work for $60,-- without a laptop. And If you will make it with an 19 pins connector and etc you’ll have to pay more.

Q23. Witch tests are included in the program? We have to research this for the 968
Those are for the 964.
Without the engine running, you can select TEST OUTPUTS. You want to lift the
engine lid and listen for the click sound of each test to verify that function. The first six (Yes we have only four of them!)
are the fuel injectors in firing order. #7 is the IACV. This has 2 clicks. An open and a
close click.. The next test is EVAP. And finally the Resonance Flap.

Edited by unknown4u, 03 June 2008 - 12:01 PM.

[Glau]

WOW! great work. The 968 community has been needing this break through for ages. I built my own interface this fall based on the 993 capacitor based schematic on R.L. but failed to get it to work and it got put on hold as my mechanic tried to reset the light and found mine is actually tripped for a reason. I plan to go with a airbagless wheel soon so until I get the wheel I decided to just live with the light (I have never seen the light off!).

With your hard work, I may pull the interface out again and test the capacitor based interface with your scantool.ini and hyperterminal com1 testing suggestions. Otherwise just buying Andy's board sure sounds like a fast easy solution knowing it works.

I would be happy to help get the images hosted for you if you want to email them to me.

Again great job!

Glau

PS. you may want to edit the title to let people know this is a solution to the airbag light and not the all to common question asking for this solution...

[Anchorman]

Glau, the thread title only makes reference to the airbag light issue, so that shouldn't be confusing to anyone. Now, and more importantly, from the perspective of an (apparently) less technologically sophisticated but very interested person (ME), I'd love to better understand if this might be leading to a reset tool that is usable and affordable. I have had the airbag light illuminated for quite some time, for one or more reasons. However, I don't know if I've cured the cause, because I can't reset the light to find out (and I haven't gotten to my OPC to have him do it for me - at a modest cost). So - where do you think this could lead?

[unknown4u]

Anchorman, As I described in the topic there is more to discover. The tool can look into the original alarmsystem. At least mine. The Motronic is not immidiatly nescessary because you can read the memory of it using the check engine light with the right procedure.
And most of us have problems with the airbag warninglight.
Maybe I can rename the topic.

Glau, The interface for a 993 is an OBD 2 interface.
And that won't work.......Buy the interface form Andy and it will talk as an OBD 1 with the 968. I have also tried the elm interface and also an KKL interface what is used by the VAG-COM. But both can not talk the "language" witch is needed.

I'm very happy using the interface, for only 60 bucks you can repair the car, have a flat baterry and you don't have to worry about the light at all. And the tool has more possibilities.

[Glau]

Glau, The interface for a 993 is an OBD 2 interface.
And that won't work.......Buy the interface form Andy and it will talk as an OBD 1 with the 968. I have also tried the elm interface and also an KKL interface what is used by the VAG-COM. But both can not talk the "language" witch is needed.

I'm very happy using the interface, for only 60 bucks you can repair the car, have a flat baterry and you don't have to worry about the light at all. And the tool has more possibilities.

This is the 993 interface I'm referring to (I only call it 993 cuz Ray built it for the 993 group, which early 993 I guess are 0bd1 with a obd2 like pug. Not our crazy 19pin plug?):

http://forums.rennlist.com/rennforums/showthread.php?t=293904

I wanted to get this one working cuz I could buy it all for like 25$ at any electronics store and last fall Andy was sold out. I bought the parts for mine at radio shack. This could possibly lead to a very easy group buy if someone wants to do some assembly or we all could potentially get in on the next group buy if there is one , the current group buy end a couple days ago. Andy's are cheap enough though that may be the easiest solution.

It will be fun seeing what all this tool can end up doing.

Glau

Attached Files

•  attachment.jpg   84.73KB   21 downloads
•  attachment2.jpg   78.16KB   32 downloads

[Mark]

Yeah they just did the final group buy on the circuit boards, I missed it by about 8 hours.

[Anchorman]

Ouch!!! Does this mean that we're left to dream about this mini-Hammer?

[unknown4u]

I checked the site from Andy. He has 5 items left in his shop.
So be very quick for this assembeld interface. it is about 20,99 GBP.
He delivers it within 10 days.

And Glau what you said is correct. But maybe you have to check the comport as well if you are using the right os platform?. Maybe you try to connect to the alarmsystem instead of the motronic first.
With this board, I know it because I red about it. But I'm sorry I can't help you out with that board. Maybe you have to check first the voltage at the K and L line in the 19 pins connector as wel as the 12 volt and ground.? Maybe your interface is good but the signals from the 19 pins connector are not good enough.

[unknown4u]

Update: The pictures are inserted with the GIF extensions.
.

[Mark]

Which site?

[unknown4u]

Read the answer of Q3.............................

[Mark]

Thanks- I scanned it really quickly for bolded hyperlinks and missed it.

[unknown4u]

To get the topic a bit smaller:

What you have to do are the following steps:

Step 1: Download the software:
Step 2: Buy the interface at Andy's shop
Step 3: Place the jumper on the outside pins.
Step 4: Cut the led of the interface marked as D4.
Step 5: Buy a female female cable 9 pins for the comport.
Step 6: Run windows 2000
Step 7: Connect the leds to the right holes in the 19 pins connector.
Step 8: Turn on the ignition
Step 9: Select the airbag option. Read the codes and clear the codes.
Step 10: Look at the dashboard and you wil have a big smile. Lights are out.

The complete topic has all the FAQ what you have to do if something doesn't work out.

Good luck,

Ritchie

[Anchorman]

OK, I'm starting to walk down this road - and Ritchie has been enormously helpful (sorry if I'm being a pest). I've ordered the interface unit, downloaded software, and will start rereading this thread numerous times. I'll post as appropriate.

[Miles'PHTurbo968]

OK, I'm starting to walk down this road - and Ritchie has been enormously helpful (sorry if I'm being a pest). I've ordered the interface unit, downloaded software, and will start rereading this thread numerous times. I'll post as appropriate.

Keep us/me posted!!!
I hope you can make this work, cause I have been very frustuated having to go to the dealer to have this pesky light reset.
Regards
Miles

[Anchorman]

I'm awaiting the delivery of the interface unit. One of the techs in my company's electronics shop has undertaken the quest for the 19 pin plug. I'm aiming to get this all done before the end of April. My airbag light has been on for more than 6 months, and I'm due for New Jersey state inspection in April. I don't know if any airbag light is cause for failure, but I'm hoping that this "mini-Hammer" will solve my problem. Otherwise, it'll be off to the OPC once again.

[Miles'PHTurbo968]

After reading this whole post a couple of times, I am still a little confused? Let's say I have the interface from "Andy's". It has a 9 pin serial male plug on one end and 4 leads on the other, right? Can you directly plug this interface into a computer and extend the 4 leads. Put conncectors on each of the 4 leads and plug them into the appropraite locations on the 19 pin diagnostic connector in our cars and then run the software?
Do we need the male 19 pin plug or additional 9 db serial cable as discussed above?
Miles

[Anchorman]

Miles, here's my view. Hopefully, Ritchie will correct this wherever necessary. Basically, I think you've got it. You don't need the 19 pin connector, you can put connector/pins on the four leads and plug them into the appropriate locations in the 19 pin connector on the car. (Actually, I believe the interface comes with 3 leads, so I'm assuming the fourth lead is the ground that must be added by the user.) A female/female serial adapter/cable is needed to connect Andy's interface to the COM1 serial port on the computer. (I'm waiting until I receive the interface to make sure I get whatever is needed to make the interface/computer connection.) Download and run the software and - SMILE.

[Miles'PHTurbo968]

Being the impulsive 968 nut that I am, I ordered one of the interfaces from Andy's right after reading this post. I'm not usually quite this impulsive but after being so frustrated over this "airbag" issue, I just got so excited I just had to have one. I have owned my car for the last 11 years and I have had my airbag light reset at the dealer on 4 separate occations costing me about 400 USD's!!!! I finally got to know one of the mechanics at the dealership who has reset my light on the side costing me 50 bucks each time...I'm smiling already just hoping this works!!!!
Thanks to ALL!!!

p.s. I know at least 6 ways to get the airbag light to go on and not go off, that is until now!!!!!!!!!!!!!

[Anchorman]

Great to have you on board, Miles. Let's see who discovers what along the way. I'm really looking forward to having a "mini-Hammer". One of the advantages for me is that my car will not provide fault codes with the CE light method. So, potentially I can gain some added information - in addition to the pleasure of the airbag reset capability.