UrS4boy

I haven't finished the conversion write-up yet but some of you are interested in the pin-outs so here they are:

1.8t Coil Pack Conversion Pin-outs

The 4 pin 1.8t 06B 905 115 L Coil Packs have their pins numbered. The function of these four pins is as follows:

Pin 1 = switched power to the primary side of the coil - connect to the yellow power input wires on the firewall metal connector rack via the scrounged VW three pin O2 sensor connectors from item No. 8 in the parts shopping list.

Pin 2 = Ground for built-in Power Output Stage - connect to pin number 2 (brown white wire) of the 4 pin connector feeding power output stage (POS) N122 (the one for cylinders 1,2 and 3). Use one of the regenderized Jetta III taillight connectors (shopping list item No. 7) to make these connections to the OE ECU to OE POS four pin connectors, as per the pin-out below.

Pin 3 = The 5 V DC signal from the ECU to control the POS switch. Use the regenderized Jetta III taillight connectors (shopping list item No. 7) to make these connections to the OE ECU to OE POS four pin connectors, as per the pin-out below.

Pin 4 = Secondary Coil Ground - connect to corner bolt of cam cover where the OE coil pack ground was located. Use a ring-type terminal under the bolt.

Reference for the above (to check): Page 97-371, Wiring diagram No. 41/4 of the Jetta/Golf IV repair manual Edition 11/99)

The POS control wires come from the 55 pin ECU connector. Three for cylinders 1, 2 and 3 are in one four pin connector that goes to POS N122. The other two, for cylinders 4 and 5 are in the four pin connector that goes to POS N127.

You need to connect Pin 3 of the 1.8t coil packs to the respective cylinder's ECU wire via the regenderized Jetta III taillight connectors. The ECU to POS pin- outs are as follows:

ECU pin 1/55 = Green wire with a white stripe for cylinder No.1 (N122 connector Pin 4/4)
ECU pin 2/55 = violet with a black stripe for cylinder No. 2 (N122 connector Pin 3/4)
ECU pin 23/55 = Black with grey stripe for cylinder No. 3 (N122 connector Pin 1/4)
ECU pin 20/55 = Black with yellow stripe for cylinder No. 4 (N127 connector Pin 4/4)
ECU pin 21/55 = Black with white stripe for cylinder No. 5 (N127 connector Pin 3/4)

NOTE: The Bently on page X52/Electrical pg. 24 is wrong about cylinders 4 and 5. The above is correct. Pin 2/4 of the OE POS connectors is the Primary coil ground that the POS controls. I wrote up a description of how the POSs work and the OE pin outs and why the Bentley is wrong at the URL below.

Enjoy (or not).

Dave<ul><li><a href="https://forums.audiworld.com/s4s6/msgs/83085.phtml">https://forums.audiworld.com/s4s6/msgs/83085.phtml</a</li></ul>

popdemonic

Thanks Dave.

audiquatro75

<center><img src="http://pictureposter.audiworld.com/42023/s4coils.jpg"></center><p>

UrS4boy

no.3. Also I would relable the "coils" as "coil packs" (because they are more than just coils) and the "Power Output Stages". For one thing N122 is POS 1 and N127 is POS No.2. More importanly, you don't connect to either N122 or N127 but to the CONNECTORS from the ECU that used to go to N122 and N127. But you have the pin numbers and wire code correct (assuming you lable No. 3 black/gray).

Good work.

I am going to try to start a separate forum for these conversions.

Dave F.