ALH ECM pinout

[4BTA4ME]

Does anyone have a pinout sheet for this ECM? I am mapping out my plan to run a Tdi in my 1998 Jetta ABA but I don't see what some of the pins do on the ALH ECM. e.g. T121/16 and T121/27. I need also to find the glowplug signal output from the ECM. One of my first steps is to map some of my Tdi signals over to my ABA instrument cluster. I was thinking of using the seatbelt light on the ABA for the glowplug light.

Also, I am looking for someone who can determine if my ALH ECm is good. All the engine wire harness conductors were severed in the accident and I fear may have shorted something in the ECM. I have contacted Rocketchip to do this but they are on vacation (Holliday ).

[lc99]

Hi 4BTA4ME, I was also trying to figure out the  T121/16 line.  I would like to find a pinout diagram ... I found some 45-pin charts but those are for older engine types, and not the ALH which I have (a 2002 Jetta TDI Wagon).

(* Removed one paragraph, since I didn't know how to read the wiring diagram and didn't understand the off-sheet track number connections!; *)

I have a problem with my drivers-side turn signal sometimes getting stuck on, when I arm or disarm the system i.e. lock or unlock ... that's why I was trying to track down some of those signals.  Thanks; Larry.

[MikkiJayne]

Is this any use? http://volkswagen.msk.ru/electro/g4/g4_wd04.pdf

Mikki x

[lc99]

Thanks Mikki, I have seen an 80-point ECM connector in that wiring diagram (wd_04).

I had recently retrieved some of those wiring diagrams from  volkswagen.msk.ru, and I also have them as printed in the Bentley book.  But while you can figure out what many of those lines are doing based on reading the connection path, some of them are not obvious.  I look in the document "g4_wd32_alh", which is also included in the Bentley book, and it shows connections to the 121-point ECM; but some of those connections aren't given a meaningful name (just a number).

I don't even know if this  T121/16 will be interesting or useful to me, it may be just a bias or sensor connection ... anyhow, I'm going to attach a probe to it when I get some time.  I think that some people with access to the full source documentation can see more about the ECM pinout; but I have only the consumer book on paper, plus whatever I can locate freely on the internet.  Larry

[MikkiJayne]

Hi again,

I think I see where you're getting stuck. The numbers in boxes represent the current track of where that wire goes to. The current track is shown by the numbers on the bottom of the diagram increasing to the right.

Looking at diagram 'g4_wd32', pin 121/16 of the ECU (shown in track 98 ) is going to track 161. Track 161 is pin T32a/5 of the dash cluster and is shown as going to track 98 (so they meet up) . It is labelled 'W', which is your tacho output from the ECU, replacing the traditional 'W' alternator terminal.

4BTA4ME - pin 27 of the ECU goes to pin T32/11 on the cluster. It's a bit cryptic to follow because there is actually a typo in that diagram on page 32/12 where the wires cross the top of the page! I can't see what pin 11 does, but it has to be either the glow plug signal or fuel consumption signal (for the MFA). It's on the same page as the glow plug light K29, but don't take that as gospel because they don't show the internal connections within the cluster.
The simple way to check is just to put a test light on it when you power everything up. If it's the glow plug the light will come on briefly. If its the MFA it won't  :wink:

Hope that helps  

Mikki x

[lc99]

Mikki, thank you very much for explaining how to read those current track / off-sheet connections.  I had totally mis-understood that, but I had a feeling that the track number was useful in some way.  (I was mixing numbers from totally different diagrams, ouch.)  Now I get it!!  (And the wire colors finally agree;)  That makes it a lot easier; Larry.

[4BTA4ME]

Thanks MikkiJayne. I've been absent for a while. I had a lot of work to do to my yard and house to get ready for a clam bake this past weekend. I can start looking at the diagrams again. Good point on checking wire signals when they power up.

[lc99]

My problem (in my 2002 model) was in the Central CCM; Not Related To ECM at all;

It was the CCM output relay that flashes the signal/indicator lights ... CCM pin numbers were 13 and 14 (which connect to the Instrument Panel's Control Module, pin numbers 2 and 18), on the CCM's 15-pin connector ... also (in the Wiring Diagram "Central control module for comfort system, antitheft warning system, antenna wire for central locking and antitheft warning system"), these go to A5 and A6 which are the turn signal/marker lights.  The Comfort CCM in my vehicle is VW part number 1C0 959 799 C.

If anyone would like to read about that particular problem ("Turn Signal gets STUCK ON, after using Key (or Remote) to Lock or Unlock doors!"), it's in TDIClub.com thread #174543, Click Here.