ALH TDI pinout.

jettawreck

Top Post Dawg
Joined
Aug 2, 2004
Location
Northern Minnesota-55744
TDI
2001 Jetta and 2003 Jetta
I'm subscribing so I can find this info easier, as I'm sure I will need to reference it. I'm doing a swap from my rear ended 2003 manual Jetta TDI into a 2003 manual Jetta 1.8 chassis. Both are/were complete cars, other than the 1.8 engine was toast. Both were almost identical equipment/option wise.
I have been using some instructions given by a vortex/TDIClub member who had done a similar swap. He leaves the gas chassis harness intact and swaps the 2 engine/ECU harnesses and wires in a 109 panel. He references this thread and diagrams, but my GP relay is vastly different in pin locations and numbers so I'm wondered in what wire to splice into on that.
http://forums.tdiclub.com/private.php?do=showpm&pmid=3196879
Comments?? Help?!
I'm otherwise ready to install the engine and send my TDI cluster and ECU off for immobilizer delete.
Hope I'm going down the right path...
 

AndyBees

Top Post Dawg
Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
Jettawreck and I have been conversing via e-mail about his TDI install in the 2003 Jetta which had the 1.8T gasser engine.

While discussing the OBD port set-up, a thought relating to the Cruise Control Operation come to mind.

Doesn't the Cluster Out-put VSS signal of the recipient vehicle need to be tapped (spliced) and sent to the TDI ECU?

ECU Pin 20 goes to T32/3, Blue side of the cluster. This is the Output Signal circuit from the Cluster to the ECU for the Speedometer data. I have to assume the data is only used for the Cruise function only as in some conversions this circuit has been omitted and the engine did just fine.


Note: the Vehicle Speed Sensor (VSS) has three wires (switched hot, ground, and out-put to the Cluster). And, there is a VSS signal sent to the ECU from the Cluster via T32/3 to ECU Pin 20, which, as stated above, is most likely used to operate the cruise function. Thus, in order to have the Cruise Function, you may need to find the same circuit for the 1.8T Cluster and splice into it for Input Data to the TDI ECU.

Or, what are you guys doing to make the Cruise functional? My conversion was in an 84 Vanagon that did not have cruise. But, since I set-up all those bells and whistles, I do have cruise.

Also, back to the OBD function. Did you guys set-up a separate OBD port to monitor the TDI engine? Obviously, the OBD use is a must, otherwise, setting the timing using VCDS would be impossible without it.
 

jettawreck

Top Post Dawg
Joined
Aug 2, 2004
Location
Northern Minnesota-55744
TDI
2001 Jetta and 2003 Jetta
I just sent a text to the vortex guy that I had been following the wiring swap instructions from which used the OPs of this thread info, and he says his OBD port functioned normally after the swap.
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
I'm looking for the specific function of the wires in the MAP/IAT sensor if anyone knows what they are.

I know there is:
+5v power
Ground
0.5-4.5v pressure signal
RTD for temperature signal

I'm guessing that Pin 2 is the temp signal, Pin 1 is either common +5v power or common ground for the two sensors and Pins 3 & 4 are pressure signal and either common +5v power or common ground depending on what Pin 1 is.

Has anyone mapped this out to this level of detail so I can fill in the below?

Frustrating that they don't provide this level of detail in the wiring diagrams.

 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
I pinned this out today...

Pin 1 = Ground
Pin 2 = Temperature - voltage goes up as temperatures go down - Has 5v pull up
Pin 3 = 5vdc Supply
Pin 4 = Pressure - voltage goes up as pressure goes up - Has ~55k ohm pull down resistor
 
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EvilLawnGnome

Active member
Joined
Sep 28, 2006
Location
Louisville, KY.
TDI
2000 Jetta
I'm working on an ALH swap into an Early Westy Rabbit. I'm keeping the early cluster, as it looks fantastic. I'm curious if there is a good way to trigger the glow plug relay light and the CEL using anything that's on the ALH engine harness. Thoughts?
 

tgray

Veteran Member
Joined
Sep 12, 2004
Location
Marengo, IL
TDI
'02 Beetle, '05 Golf, 2000 Jetta, 2001 Jetta, 2002 Jetta
Using proper ground wire connection point in your wires

I have not seen any mention of this in the write ups and the understanding is not always obvious so I am going to try to explain why the VW original plan should be followed if possible. This is important when you are doing a conversion because it is tempting to find a ground wire and splice it into another ground wire without understanding why there are so many running all over the place.
Back in the old days before computers all you needed to do was bolt down a ground wire to the frame and splice in where every you wanted with no problems. Now, with computers it is a different world. Wires have resistance and so do grounding points. Resistance in long runs adds up and to make the problem worse, the sensors often are read on voltage drops or resistance. So just that in itself will cause problems if they are not hooked up right. The other part of the problem is what is called a ground loop. A ground loop is where there is a potential difference between one ground point and another. The path of the current will start going places you don't want or even will know if things are not on the common plane of reference. Wires switched on and off will create pulses that induce stray voltages back into other wires that affect the computer system. When you see the twisted pair wires (this is to help stop induced voltages from the pulses), these are for the CAN Buss system that send digital messages and a stray pulse or 2 will really mess your ECU communications up. This is not good because how do you troubleshoot something like that?
I have pulled apart the MK4 wire harness and see many small ground wires lugged together into one big ground wire before it goes to the grounded lug. The purpose of VW designers is to bring the grounds together to one common point to keep resistance as equal as possible to one common plane between the critical components. Things like lights and horns can be just bolted down where it is works the best.
Can you ground a wire anywhere in your conversion and find the car will start and run. Probably so, but keep in mind that VW didn't just pull wires all over the car and bundle them together when they could have easily found a closer ground point for less expense and hassle.
If grounding is confusing try to think in terms of landing a common point with other wires rather than going where it is quick and easy. If you do need to splice a wire in without being sure, it is always better to splice a little wire into a big wire that goes to the ground. At least the resistance will not go up so much. I haven't verified it but I think VW uses tracers on some of the more critical grounds that should be lugged together at a common point.
 

zspace

New member
Joined
Aug 7, 2017
Location
lac simon qc
TDI
2001 jetta
i have found the picture dont know how to post them anybody needs them send me a pm with your email adress i will send them to you
 

fjdiesel

Well-known member
Joined
Oct 2, 2017
Location
MN
TDI
76 fj40 w/02 ALH, 04 Jetta BEW
Andybees I see it has been over a year ago since you referenced the VSS wiring for the cruise control function. Did you or anyone make that work? Or can you just put the VSS signal directly into the ecu if your conversion is not in a vw?

zspace I sent you a pm also. Thanks
 

oilcan_boyd

Veteran Member
Joined
Sep 15, 2003
Location
St. Albans, WV
TDI
2012 Touareg TDI Sport, 2005 Wrangler Unlimited TDI
Andybees I see it has been over a year ago since you referenced the VSS wiring for the cruise control function. Did you or anyone make that work? Or can you just put the VSS signal directly into the ecu if your conversion is not in a vw?

zspace I sent you a pm also. Thanks
I am also interested in getting cruise control to work. I took the Jeep on a 1000 mile round trip and my right leg got a little cramped up.
 

Motohead1

Veteran Member
Joined
Jul 16, 2016
Location
charlotte
TDI
2002 bug+telephone pole
Andybees I see it has been over a year ago since you referenced the VSS wiring for the cruise control function. Did you or anyone make that work? Or can you just put the VSS signal directly into the ecu if your conversion is not in a vw?

zspace I sent you a pm also. Thanks
I am also interested in getting cruise control to work. I took the Jeep on a 1000 mile round trip and my right leg got a little cramped up.

The VSS is covered in several builds but to recap. You need a valid brake switch/ signal. and a VSS pulse. The VW is 8000ppm signal. Dosent have to be exactly that ppm but its nice to have speed match up for logging. HTH
 

superhl

Veteran Member
Joined
Jul 21, 2017
Location
27534
TDI
2002 new beetle
pictures

vduspeed,
Could you email me these pictures? I am in the process of converting 1992 isuzu pickup to 2002 vw TDI diesel? I can't open these images. Thanks
 

jhax

Veteran Member
Joined
Jan 24, 2012
Location
Golden, CO
TDI
96 Passat B4V, ALH engine out of a 2002 Jetta, some IE Rods and ASV Pistons. Nothing drivable yet though
For the cruise control, in my research, I have found that ECU (T121/20) SEEMS like it is for cruise control, the AHU/1Z equivalent is T60/43 on the ECU. If you are using a MK3 gauge cluster, ECU PIN 43 goes to W/1 on the CE2 fuse box and out of the fusebox at U2/2 "Speed Sensor" on the a2resource website. So if I am correct, and if you are using a MK3 cluster/fuse box ALH ECU (T121/20) goes to W/1 and then to the speed sensor in the cluster.
 

dremd

Veteran Member
Joined
May 31, 2007
Location
South Louisiana
TDI
06 sprinter. 03 jetta wagon premium with 6 speed ALH swap, 14 JSW
I have them printed in my glovebox, I’ll get them to you when I get back to my TDI probably Friday
 

Bolts-n-Hose

Active member
Joined
Nov 9, 2017
Location
New Hampshire
TDI
TDI
Can someone confirm what I think may be an error on the diagram above? It appears to me that (at least for my 01 Jetta) the red/purple shares the 30 amp constant 12v fuse with the main power to the ECU. This diagram shows this 30 amps being switched off of relay 109.
 

AndyBees

Top Post Dawg
Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
I realize this is a late response ....

Bolts-N-Hose, yes, the circuit that goes through 14a/5 is switched via the 109 Relay as shown in the diagram in this Thread. The fuse in question is #32 in the original application.

My notes, Bentley, etc., confirm it and that's how I installed it in my conversion.
 

blkhatsilhouette

Well-known member
Joined
Jun 21, 2007
Location
Portland, OR/Chelmsford, MA
TDI
2003 Wolfsburg Jetta TDI
Hey everyone, I'm in the middle of swapping an '00 ALH/5 speed into an '03 1.8t/automatic (both were jetta's).

I'm having trouble with the T14a connector that the pin out is shown on this thread. In the 1.8t jetta, I'm missing pin 3 (green) and pin 10 (black with green stripe).

On the harness that was in the 2000, it has these wires, and I traced them around on the hacked up harness for comparison.

I know that pin 3 of this connector should go to pin 28 on the blue connector of the instrument cluster. I don't have the green wire on the T14a connector, but there is a green wire in the blue connector of the instrument cluster... where does that green wire go to on a 1.8t?

I also see on the diagram that pin 10 should go to the load reduction relay. I traced this black/green stripe wire to fuse 10 (small fuses) on the 2000 wiring, but it doesn't seem to exist on the 1.8t. The bottom blade of the load reduction relay traces continuity to fuses 20, 21, and 36 on the 1.8t, but those also exist on the TDI, so I need that extra wire...

Any input would be greatly appreciated!

Thanks!
 

simbatheking

Member
Joined
Aug 24, 2018
Location
invermere
TDI
01 jetta
Pita harness

I am trying to remove the harness from my donor 03 Jetta in one piece but it’s quite the pita. It goes everywhere. What is everyone doing about this? Do you remove the entire harness or are you guys building your own harnesses? What’s the process for getting the factory harness out if required?
 

dremd

Veteran Member
Joined
May 31, 2007
Location
South Louisiana
TDI
06 sprinter. 03 jetta wagon premium with 6 speed ALH swap, 14 JSW
Remove engine harness. And cut off body side plugs as a rule.
The secret spot is in the fender well near battery on golf/ Jetta and under cowl on beetles. You have to pull water tight box on everything.
 
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