jjbunn

What's the frequency of those pulses, Loren? Two of the handheld multimeters I have include a Frequency measurement setting, which is good to around 500kHz I think. That would avoid lugging the benchtop frequency counter to the car :-)

Lorenfb

Check these out:

https://rennlist.com/forums/showpost...4&postcount=43

https://rennlist.com/forums/showthre...=Knock+counter

Haven't actually scoped the knock pin on the 964, but it should be similar to the 944 Turbo
knock data output. I would probably use a 100KHz counter to sample the knock output.
The counter should have a "gate" button/switch/input to start a sampling period, e.g. the
1st knock starts the counter.

kgorman

I got my setup working tonight! I used a completely different cabling setup than others. I just decided to make a longer cable because I was using a desktop computer in the garage. I utilized two db9->RJ45 connectors, then put a standard 25ft ethernet cable between them. The connectors are a kit where you can put the pins in whatever location you wanted. I guessed and got it right, just wire up all pins except pin 1, wire all the colors in the same exact position on both connectors. I got the kits at Fry's: Pan Pacific # ADM-978-GR

I cleared my blower motor related faults from when I removed it, but other than that not much to report.

Now I just need to create the project box, put pins on the wires, and tidy it all up a bit.

On a side note. I don't know how people actually use windows computers, windows took me more time with all it's updates, drivers, and associated crap than the whole rest of the project.

Thanks Doug and everyone for the work you put in, really nice work everyone!

Here are some pics of the connectors I used:

chancecasey

Great thread refs Loren! So it seems the key is knowing exactly what the signal duration is coming from the DME - if your sampling period is smaller than the signal duration, you'll read more counts than are there - assuming you do read some. If your sampling period is too large, you may read less, or maybe zero, knocks.

I noticed the device mentioned on those threads have a 500Hz sampling rate - way slower than what you've recommended so far. If someone can tell what the signal duration is, it should be pretty easy to make a simple dedicated counter device, yes?

tkacki

Hi,

I use scantool with my 944S2 and 968. I prepared the interface myself (transoptors). There are several issues when using scantool with above cars. There are differences in DME wakeup signal (L), different channel assignations (ecu inputs, actual values), and in case of 968 different trigger for adaptation. Some issues can by partially solved editing scantol.cfg file but others not. Is the scantool a open source software ? Where or how can I download the source or collaborate in the project to adopt this software to be compatible with 944/968 ? I am a software developer.

Laurence Gibbs

The software to the best of my knowledge has never been issued open source. There may be a few people on here though who might lead you in the correct direction.

unknown4u

Hi Tkacki,
I'm also having a 968 and have done quiet a lot with the interface as described.
The hardest thing is to connect to the motronic. hardly impossible. but with the standard blinking from the check engine light this is not a prior to me.

tkacki

To get connected You have to skip wakeup on L line. DME is at address 0x10 and transmission speed ie 9600 baud.

unknown4u

Hi Tkacki,

Thanks for this info.
I'm interested how your scantool.cfg looks like. This about how I can skip the wakeup on the l-line incase of the motronic.

Ritchie,
Owner of a 92 coupe with the M030 option.

tkacki

No way to do that with cfg modification. Change in the software is needed. Thats way I ask for info.

springer3

Has anyone used the scan tool on a 91 turbo? We tried on Boeing 717's car. It read the climate control, SRS, and ABS just fine, but no answer from the Motronic. Fortunately, the problem was the airbag light.

unknown4u

That is the same problem we have with the 968.
But lucky for us the faultcode can be read with the procedure with the check engine light on the dashboard.

Ritchie
Owner of a 92 coupe with the M030 option.

The Flying Dutchman

Maybe this question was asked earlier. But did anyone here made a mobile phone OS interface of the Scantool software by any chance, especially for Android I have an Android and would love to have an app which I could use during the occasional trackday.

For the hardware I use the Bervfill and I can buy a USB-to-micro-USB connector to get the hardware connected to my mobile phone.

Hallsy

I know this an old thread, so sorry for dragging it up with my first post - but it is relevant!

My 1988 944S uses the Bosch M2.1 dme, which is the same DME as used by the 964 - which this software/interface was designed for?

Today I tried connecting up to my 944 via a DIY lead I had, a Bosch KTS 520 and PIWIS software. Under the 944 menu it could see the DME and read faults, but no more. Under the 964 menu it could read engine sensor values, etc and also offered system adaptation - but when tried it came up with an error.

As the software mentioned in this thread was based on the 964, but specifically for the Bosch M2.1, will it work OK with the 944S DME?

JasonAndreas

If you modify the config file so that the actual values point at the proper CPU (memory addresses/registers) and change the fault codes it should work. System adaptation will probably not work but its worth trying.