the flyin' scotsman

The PEMs I installed were pre-loaded also.

Andrew...........the pic of the EZK shows the PEM marked LH, how was the other PEM marked?

Bill Ball

I couildn't find anything that matched it in the wiring diagrams.

AO

They're both marked "LH2.3/EZK"

fraggle

Ok bonehead question. How can I tell what year my brains are from? I believe my '87 has '89 brains in it, but my memory is foggy.

That question is hilarious taken out of context. Sigh.

jcorenman

I am sure there is a list of part numbers somewhere...
This is from the WSM, plus some observations (marked with *):
'87 = 928.618.124.10 and .11 * (also listed in WSM)
'88 = 928.618.124.12 and .14
'89 = 928.618.124.15
'90 GT = 928.618.124.22 * (not listed in WSM)
'91 S4 = 928.618.124.25
GTS = 928.618.124.30

Cheers, Jim

jcorenman

Andrew, following up on your EZK problem yesterday:

My spare EZK is an '87, but a "dot 11" (as in 928.618.124.11), while yours is a "dot 10". I got a PEM for mine and just finished getting it installed. Short story, it works fine.

The "dot 11" EZK did have the extra capacitor-board, but one piece not two like yours. I removed it, confirmed that the EZK still worked and then installed the PEM (pre-loaded for the EZK). Hooked it up, started car, all good. I fired up Sharktuner, it reported PEM's in both ECU's (as yours did), I loaded a new GT EZK image, it uploaded fine and ran, stopped and downloaded from PEM's, that worked OK also, car still ran fine.

Sooo.... Either there is a difference in the EZK PCB design from dot-10 to dot-11, or something happened to your PEM, or the K/L bus wiring to the EZK may not be correct (it is a very early EZK-equipped car, and the "L" bus may never have been used before).

So swapping the PEMs between EZK and LH (and reloading) will be a good test, also check the "L" bus continuity.

For your '87:
K-bus is diagnostic pin-10, LH pin-12, EZK pin-1
L-bus is diagnostic pin-12, LH pin-16, EZK pin-7

I didn't seen anything in the EZK that suggested it would be unhappy running half-apart, in fact I tested mine after the radical cap-ectomy with the PCB's sitting naked on the carpet and it worked fine.

Can you email some hi-res pic's of your EZK boards? (Both sides). I'll have a look at the circuits compared to the dot-11 and see if anything is different around the diagnostic traces. "Support at sharkplotter dot com" should work for large pic's, goes through gmail.

I hope this helps. John will be back late tomorrow so we can get some real answers then

Cheers, Jim

AO

Well it works... when it wants to.

I swapped the PEMs and plugged just hte LH in. It loaded up fine. So I then put the known-good PEM into the EZK. It loaded up fine! Whoo hoo. So I jumped in and went for a drive.

While I was out driving I noticed the STer lost the signal from the PEMs. Tried reloading and it couldn't find the PEMs - either the LH or EZK. So I decided to drive it home before I screwed it up.

Once i got it home I disconnected the LH and the EZK and reconnected. No change. Still won't connect.

So then I unplugged the cable from the STer and reconnected. No change.

Next I unplugged the cable from the diagnostic port. Seemed loose. I tried tweaking the pins a bit so they would be a bit tighter in the diag port. BINGO! Looks like the plug/port connection might not be the best. Will play a couple more days to see if the problem comes back.

So, in short, it looks like all the very early cars should work fine. But gotta make sure the 24 year old connector is free of corrosion and that the plug seats well.

jcorenman

I knew there was a reason that connector design didn't take over the world... Good catch, hope it keeps working!!

John Speake

Thanks Jim and everyone who chimed in here to help Andrew.

I have never known an MY87 S4 not to have the 12 way diagnostic connector. It is the only 12way connector anywhere near the CE panel. The earliest S4's had in mounted on the ECU plate, but usually it has been unclipped at some point and can sometimes be found buried behind the LH/EZK/ECUs.

Good idea to tighten the pins /sockets, they are not a perfect fit.

The ST 12W lead and the diagnostic connector plugs don't match exactly pin to socket, there are some unused pins. But always be wary that someone might have accidentally had the connctor on the car apart, and not replaced the sockets in the correct positions.

Also note that the "Spanner" 12way lead will NOT work with ST (and nice-versa) . All ST leads have a white square at the end that plugs into the ST box.

The mod to the early EZK boards is shown in the User manuals...... as has been said. You will losoe a couple of bypass surface mount capacitors when you snip a section out to clear the PEM, but they are not necessary, just tidy up any stray copper foils and bits of debris.

Tony

Perfect timing with this...i just started having issues like that. I will look at it.

Jadz928

Andrew,
My early '87 has a similar connection. What does this mean?

AO

It means you're good to go for shark tuning and using the diagnotic tools if you have chips with diagnostic capabilities (earlier '87s don't have this - easily upgraded.)

AO

BTW, I got a chance to look at my busddy's car and there was no other similar connector, so I have to assume that someone has messed with his plug. There was evidence that someone had messed with the wires. Looks like I'll need to map them out to the LH/EZK.

Can anyone (John?) tell me what the 9 pins are on the diagnostic plug so I can confirm that they are there and re-arrange them?

Jadz928

Thanks Bromo!

John Speake

Here you go Andrew, the pin functions are shown. The diagram is showing the ST lead as per your picture.

You will have some "spare wires" which are not used with ST. These are Hall signal (2nd pin down from top, LHS) , Knock (2nd pin up on RHS) and RPM (2nd one up on LHS)