glow plug control module

[trev]

I've stripped a '95 B4 Passat with AAZ engine to gather a few parts that I might need to finish off my conversion. Mind you, my engine is just a 1Y, the Passat was already relieved of it's engine before I got it

Anyway, I would like to use the glow plug control module to operate the glow plugs for me. From doing a little google research, I gather that this is what VW used on the AAZ before it went to ECU engine management with the 1Z. As far as I can gather, it uses a temperature reading from the cylinder head water flange to determine how long to glow and how long for the glow to stay on after the engine has begun running.

The module itself is like a "double wide" relay, each side having 9 pins. I took the wiring loom attached to the module with it so the factory plug is attached. I presume it takes such feeds as switched live from ignition, permanent live from battery, temp reading from engine sensor, probably a signal from the alt to tell it the engine is running. Presumably the outputs are to the glow plug light on the dash and to the glow plugs themselves via the heavy duty fuse.

So, there are 18 pins on the module. Does anyone have any idea what they all do, if any of them can be ignored or a pin-out diagram or circuit diagram or anything that might get me started on the road to automating the glow plugs?

If all else fails I'll just do the simple "switch on the dash" system but I'd like if at all possible to do this the factory way

All help appreciated

[trev]

while the module might look like a "double wide" relay, it's actually nothing like one. I opened the box expecting to find a solenoid and some electrical contacts. I found what resembles a computer mother board, complete with big square chip and micro components!!!

I reckon it also controls those things on the injector pump that we discard with the conversions into our vans. I reckon it's going to be too awkward to get it all running as I would like it to so I'm probably just going to go the "pressing and holding a button on the dash" route...

unless I can find any more information. Even a pin-out of the big round engine loom connector on an AAZ would do the job...

[trev]

I found a PDF of the Bentley manual for the B4 passat which gives very useful wiring diagrams:

http://vwts.ru/electro/b4/b4_wd_1995.zip

and I've figured out almost all of the pins/wires at this stage. I reckon with a bit more headbanging I can get this thing working.

Anyone got any idea why it would need a signal from the door contact switch (the one that switches on the cabin lighting)??

[13 window deluxe]

if i remember correctly the aaz glowplug module also controls the vac solinoid for the egr valve.

if it was me i would just buy a t25 or mk1/mk2 golf diesel glow plug relay there very simple and there are only 6 wires to connect. battery input via 50amp fuse glow plug feed, earth, ignition live, starter motor crank feed and glow plug light output. with this relay the glow plugs only come on when the coolant temp is low enough and if you start cranking before the light is out the relay goes of to save the battery
_________________
1964 rat 13 window deluxe 1Z tdi,
1975 rhd twin slider tintop (TBA)
1991 golf 2 gti with tweaked AHU tdi,

previous tdi swaps: gone but not forgotten
1979 rhd twin slider tintop bay ahu 1.9tdi
1990 T25 1Z 1.9tdi
1993 suzuki samurai with 1Z 1.9tdi

[13 window deluxe]

[trev]

that's interesting. So if for example you went out to your car to get something out of it it would give the plugs a warm up just in case?

anyway, I've been doing a bit of research on the subject and I've identified almost all the pins of the engine control module and all of the pins of the 17-pin plug that connects the engine loom to the main car loom.

Since I hate to see this kind of thread die unanswered and the information might be useful to someone else in future, I'm going to post my findings. If nothing else, it'll add a little value to the forum

[trev]

I think it would be nice to automate the rudimentary management on the engine, but mostly the glow plugs. Here is what I have found out about the engine control module (also called the glow plug control module). It does more than just the glow plugs though...



So the module itself looks like a double wide relay. It's fitted to the bulkhead above the fusebox on the 1995 AAZ-engined B4 Passat, with the 50A relay for the glow plugs fitted beside it. Neither are attached directly to the fusebox but they are linked to it via certain plugs.



The module has 18 pins but only 16 of them are used. The plug that fits to the module is referred to as "T18" on the VW wiring schematics, as it has 18 poles. Most of them output directly to the big round 17-pin harness connector on the engine (referred to as "T17" BTW) but some go to plugs on the fuse box and more go to small one or two-pole harness connectors.

Using the PDF of the Bentley manual ( http://vwts.ru/electro/b4/b4_wd_1995.zip ) I deciphered the poles of the plugs.
I got info on the fusebox plugs G1 and G2 here: http://www.a2resource.com/electrical/CE2.html



Here's the pin-out for the T18 connector on the engine control module:
for clarification "T17/5" means pole #5 on the 17-pin round connector on the engine. "G2/4 means pole #4 on fuse-box plug G2.



pin colour - - - - - -goes to:

01. green - - - - - to G158 injection start sensor
02. not used
03. blue/white - - to T17/5, pole #3 engine temp sensor
04. black/yellow - to G2/4 (through 10A fuse #15, which is an ignition-switched live)
05. not used
06. brown/green - to T17/9, injection start sensor
07. brown/yellow - to door contact switch
08. brown/white - to G1/5 (body earth) and T17/8 (cyl.head earth)
09. red - - - - - - - to G2/9 glow plug pin 6 (permanent live)
10. blue/yellow - - to G1/3 engine temp sensor
11. blue/green - - -to G2/5 glow plug relay pin 9 (glow plug indicator light also water separator sender)
12. blue/red - - - - to 2-pin harness connector (idle air control solenoid)
13. brown/black - to 2p -pin harness connector (EGR control)
14. green/black - to T17/3 (N165 injection start positioner)
15. brown/blue - - to single grey harness connector (Air-con)
16. red/white - - - to track 40 (joins glow plug wire just before T17 connector)
17. white/red - - - to single brown harness connector (OBD)
18. yellow- - - - - to single yellow harness connector (OBD)

the wires that don't go directly from the T18 to T17 plugs terminate in this bundle of harness connectors:

[trev]

going from the other end, not every pin on the T17 round harness connector on the engine goes to the engine control module. Some go to the G1/G2 clear fusebox plugs and one goes to a single pin OBD connector.



pin out for the T17 round engine harness connector:

pin - colour - - - - - - connects from - - - - - - goes to

01. red/white - - - glow plug bus bar - - - - - - 50A fuse onwards to glow plug relay pin 4/87
02. brown/blue - - - earth on cylinder head - - - - - - G1/5 (body earth) and T18/8
03. green/black - - -N165 injection start positioner - - - T18/3
04. red/white - - - glow plug bus bar - - - - - - - 50A fuse
05. blue/white - - - coolant temp sensor pin 3 - - - T18/3
06. not used
07. yellow/red - - - coolant temp sensor pin 4 - - - G2/3 (temp gauge on dash and glow plug relay pin 3/85)
08. brown/white - - - cyl head earth - - - G1/5 (body earth) and T18/8
09. brown/green - - injection start sensor - - - T18/6
10. green - - - - - - G158 injection start sensor - - T18/1
11. not used
12. yellow - - - - - oil pressure switch - - G2/10 (oil pressure warning light)
13. not used
14. white/red - - - (unknown as of yet) - - - single pole OBD plug (brown)
15. blue/black - - - 0.3 bar oil pressure switch - - - G2/11 (oil pressure warning light)
16. black/yellow - - - cold start solenoid - - - G2/4 (switched live)
17. black/yellow - - - fuel cut off solenoid - - - G2/4 (switched live)

[trev]

as you can see there are still a couple of unknowns amongst the list. I'm going to check off the actual engine wiring to see where they go.

I thought I was doing the right thing snipping the wires on the electrical doobries on the injector pump with the exception of the fuel cut off solenoid. Now that I know what everything is and how I can hook it all up in the van I'm sorry I snipped them.

[trev]

figured out all the unknowns bar T17/14