www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2016 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You

Order your TDIClub merchandise and help support TDIClub


Go Back   TDIClub Forums > VW TDI Discussion Areas > TDI Conversions

TDI Conversions Discussions on converting non TDIs into TDIS. More general items can be answered better in other sections. This is ideal for issues that don't have an overlap and are very special to swaping engines.

Reply
 
Thread Tools
Old December 27th, 2019, 08:52   #1
Millennium Falcon
Veteran Member
 
Join Date: Nov 2016
Location: Central pa
Default 120 pin ALH Tdi analog tach install

I thought this info would fall under the "google it" catagory since it seems so basic.... I i didnt want to ask a question that has been asked a million times so I tried searching it and didnt come up with much. So here are my findings. I realize its elementary but maybe it will help someone.

Ive been using a tiny tach on my ALH swap but really wanted an analog tach. So I looked at my pinout and found that #27 pin of a 120 pin alh ECU is the tach signal. The book says Green/brown wire) It looks like the AHU, and 80 pin ALH have a wire in the harness for tach signal but the 120 pin ALH does not.



The 3rd hole in from the left in the row above the blue wire is #27. This is the larger of the two ECU plugs.






When I disassembled the plug I found the pin to be in place with a small piece of insulation (brown & Green) not sure if this is how all ALH's are or if someone cut mine... I have two harnesses and they both are like this.
Knife is pointing at #27







Here is the pin removed.







I stole a pin and a length of wire from a spare harness......






I put everything back together and hooked it up to the tach. This one has adjustable dip switches but I didnt have to mess with them at all. It was dead on right out of the box.





I compared the new tach with my old tach and VCDS. All is good! Dont worry this engine is in my 71 year old Jeep and will never see 4000 rpm. I chose this tach because its very easy to read from 1500-2550 which is where i usually live.





The final product!

https://youtu.be/9jLoXL-lgGA



Hopefully this can assist someone who is trying to get info on this procedure. Thanks!
__________________
2003 Jetta TDI wagon, 5-speed, swap, Sprint520 nozzles 165k
2004 passat 1.8t auto 104k

1949 Willys cj3a ALH tdi swap

Last edited by Millennium Falcon; December 27th, 2019 at 09:24.
Millennium Falcon is offline   Reply With Quote
Old December 27th, 2019, 09:15   #2
eddieleephd
Veteran Member
 
Join Date: May 2012
Location: Asheville, NC
Fuel Economy: 38mix / 47@70-75
Default

Awesome write up! Now I know where to point someone

Sent from my moto g(7) power using Tapatalk
__________________
'02 1.8t Jetta Wagon Alh w/5spd swap, SB 21#SM DD, bew lift pump, 11mm IP, VNT17, Malone stage4 tune, 2.5"cat back st. pipe,Vr6 brakes, 2" lift, Panzer, Bilstein HD, Bosio DLC 1019's PD_fuel_delivery TDI Search Plug release tool Howto terminal release tools VW/Audi
eddieleephd is online now   Reply With Quote
Old December 27th, 2019, 10:52   #3
CasaEd
Member
 
Join Date: Mar 2017
Location: Portugal
Default

Pin 27 deffo tacho signal in all 121 pin ECU's, PD included, looks like someone cut the wires in your looms. You can take an analog signal from one of the windings in the alternator before it passaes through the diode, but if you are using the VW alternator it will only read correctly on a VW analog diesel gauge, this is what I have done in my ASZ converted B3 passat.
CasaEd is offline   Reply With Quote
Old December 27th, 2019, 19:58   #4
1.9ZOOK
Veteran Member
 
1.9ZOOK's Avatar
 
Join Date: Dec 2015
Location: Dunsmuir,Ca.
TDI(s): ALH Samurai
Fuel Economy: pending
Default

Nice!
1.9ZOOK is offline   Reply With Quote
Old December 27th, 2019, 20:35   #5
Millennium Falcon
Veteran Member
 
Join Date: Nov 2016
Location: Central pa
Default

Thatís what I thought too... several people told me that I would have to add the wire. I was told the 1.8/vr6 have the wire but the tdi does not. I have two harnesses and they are both like this. I removed one from a stock car myself. So Iím hearing and seeing conflicting info.

Quote:
Originally Posted by CasaEd View Post
Pin 27 deffo tacho signal in all 121 pin ECU's, PD included, looks like someone cut the wires in your looms. You can take an analog signal from one of the windings in the alternator before it passaes through the diode, but if you are using the VW alternator it will only read correctly on a VW analog diesel gauge, this is what I have done in my ASZ converted B3 passat.
__________________
2003 Jetta TDI wagon, 5-speed, swap, Sprint520 nozzles 165k
2004 passat 1.8t auto 104k

1949 Willys cj3a ALH tdi swap
Millennium Falcon is offline   Reply With Quote
Old December 28th, 2019, 04:38   #6
jimbote
 
jimbote's Avatar
 
Join Date: Jul 2006
Location: spiral arm, milky way (aka central NC)
Fuel Economy: golf=38-43mpg...tacoma tdi=29-33mpg
Default

https://forums.tdiclub.com/showpost....90&postcount=4
__________________
'You know what? This is a business.' So, now, I just keep my mouth shut and pet my chihuahuas." Mickey Rourke
jimbote is offline   Reply With Quote
Old December 28th, 2019, 08:51   #7
jhax
Veteran Member
Default

Now, that's what this forum has been missing!
jhax is offline   Reply With Quote
Old December 28th, 2019, 11:11   #8
CasaEd
Member
 
Join Date: Mar 2017
Location: Portugal
Default

Nice list @jimbote, but I also like to use pin 18 which is the earth switch wire for the ECU control relay
CasaEd is offline   Reply With Quote
Old December 29th, 2019, 18:03   #9
jimbote
 
jimbote's Avatar
 
Join Date: Jul 2006
Location: spiral arm, milky way (aka central NC)
Fuel Economy: golf=38-43mpg...tacoma tdi=29-33mpg
Default

Quote:
Originally Posted by CasaEd View Post
Nice list @jimbote, but I also like to use pin 18 which is the earth switch wire for the ECU control relay
which ecm are you referring to? pin 37 on the 121 ecm is the wake up wire, then the ecm sends "earth" to relay 109...i'm not short-cutting the factory pathways... can you clarify your approach?
__________________
'You know what? This is a business.' So, now, I just keep my mouth shut and pet my chihuahuas." Mickey Rourke

Last edited by jimbote; December 29th, 2019 at 18:06.
jimbote is offline   Reply With Quote
Old December 31st, 2019, 12:04   #10
CasaEd
Member
 
Join Date: Mar 2017
Location: Portugal
Default

Pin 37 is the feed from the ignition switch which then lets pin 18 go to earth which energizes the ECU relay which then sends power to the ECU to get it up and running, and yes I'm talking about the 121 pin ECU's, the 80 & 68 pin ECU's also power up the ECU in the same way, but the pin numbers are different,On the 68 pin ECU Pin 38 is the ignition feed & pin 42 earths the EC relay, on the 80 pin ECU pin 47 is the ign feed and pin 33 is the EC relay earth wire. Hope this helps

Last edited by CasaEd; January 4th, 2020 at 12:51. Reason: Incorrect Information regarding pins
CasaEd is offline   Reply With Quote
Old January 2nd, 2020, 08:57   #11
jimbote
 
jimbote's Avatar
 
Join Date: Jul 2006
Location: spiral arm, milky way (aka central NC)
Fuel Economy: golf=38-43mpg...tacoma tdi=29-33mpg
Default

Quote:
Originally Posted by CasaEd View Post
Pin 37 is the feed from the ignition switch which then lets pin 18 go to earth which energizes the ECU relay which then sends power to the ECU to get it up and running, and yes I'm talking about the 121 pin ECU's, the 80 & 68 pin ECU's also power up the ECU in the same way, but the pin numbers are different,On the 68 pin ECU Pin 38 is the ignition feed & pin 23 earths the EC relay, on the 80 pin ECU pin 47 is the ign feed and pin 33 is the EC relay earth wire. Hope this helps
still confused by your post, if maintaining the stock pathways why would you need to touch pin 18? it's function is undisturbed and not really worth mentioning unless there is damage to the stock wiring.
__________________
'You know what? This is a business.' So, now, I just keep my mouth shut and pet my chihuahuas." Mickey Rourke
jimbote is offline   Reply With Quote
Old January 4th, 2020, 12:58   #12
CasaEd
Member
 
Join Date: Mar 2017
Location: Portugal
Default

Ok, pins 18,42 & 33 is what the ECU sends to earth to enable relay 109 or 53 to send main battery power to the ECU when you turn the ignition switch on i.e pin 37 on the 121 pin ECU. Relay 109 is not turned on by an ignition feed, it has permanent battery feed at pin 30 and when pin 42 is earthed it switches the relay on which in turn sends
power through pin 87 of the relay to pin 23 of the ecu which then turns it on.
CasaEd is offline   Reply With Quote
Old January 4th, 2020, 17:49   #13
jimbote
 
jimbote's Avatar
 
Join Date: Jul 2006
Location: spiral arm, milky way (aka central NC)
Fuel Economy: golf=38-43mpg...tacoma tdi=29-33mpg
Default

Quote:
Originally Posted by CasaEd View Post
Ok, pins 18,42 & 33 is what the ECU sends to earth to enable relay 109 or 53 to send main battery power to the ECU when you turn the ignition switch on i.e pin 37 on the 121 pin ECU. Relay 109 is not turned on by an ignition feed, it has permanent battery feed at pin 30 and when pin 42 is earthed it switches the relay on which in turn sends
power through pin 87 of the relay to pin 23 of the ecu which then turns it on.
yes, i understand that relay 109 is not directly turned on by the ignition switch, but is grounded by pin 18 of the ecm, so why are you concerned with pin 18? unless you are bypassing the ecm grounding ? and grounding the relay yourself to excite relay 109?
__________________
'You know what? This is a business.' So, now, I just keep my mouth shut and pet my chihuahuas." Mickey Rourke
jimbote is offline   Reply With Quote
Old January 6th, 2020, 13:57   #14
CasaEd
Member
 
Join Date: Mar 2017
Location: Portugal
Default

I did'nt see pin 18 on your list
https://forums.tdiclub.com/showpost....90&postcount=4
CasaEd is offline   Reply With Quote
Old January 11th, 2020, 06:48   #15
jimbote
 
jimbote's Avatar
 
Join Date: Jul 2006
Location: spiral arm, milky way (aka central NC)
Fuel Economy: golf=38-43mpg...tacoma tdi=29-33mpg
Default

Quote:
Originally Posted by CasaEd View Post
It doesn't need to be on the list... i only listed wires and pinouts that require attention when making a standalone harness. The wire coming from pin 18 is NOT one of those because it's path remains undisturbed between the ecm and R109. If you are disturbing that wire, you are taking an unnecessary step.
__________________
'You know what? This is a business.' So, now, I just keep my mouth shut and pet my chihuahuas." Mickey Rourke
jimbote is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Analog clock install Passat 03Springer Upgrades (non TDI Engine related) 0 April 14th, 2019 15:55
06 jetta tdi to install cam pin. fluxcore TDI 101 3 July 24th, 2018 06:20
80 pin alh vss pin? pr0cess0r TDI 101 4 February 15th, 2014 11:15
Is it worth updating to a 120 pin ECU? tdibeliever TDI Power Enhancements 9 November 11th, 2009 21:49
1996 1Z TDI Tach Wire Doesn't Operate Mk1 GTI Tach CrewCabCaddy VW MKIII-A3/B4 TDIs 1 April 9th, 2005 16:20


All times are GMT -7. The time now is 21:24.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2017
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
© 1996 - 2017, All Rights Reserved
Page generated in 0.17942 seconds with 11 queries
[Output: 130.54 Kb. compressed to 108.95 Kb. by saving 21.60 Kb. (16.54%)]