The Rabbit TDI Project
Part 6: Wiring 3: Of Keys and Readers, IMMO3
Or: Throbbing headaches of antitheft
My TDI engine has an Immobilizer.
IMMO3 = good idea, but not for retrofitting engines to older cars.
The IMMO system consists of three parts, the ECU, the cluster, and the key/key reader. The ECU must know the cluster, the cluster must know the ECU and the keys. The keys, well they're just hanging around because they have nowhere to go.
My cluster was brand spanking new, my ECU was used, my key came from Ebay.
With the TDI engine and cluster, my 1982 Rabbit is now OBDII, complete with communication port. A borrowed laptop and a VAGcom license lets me communicate with my cluster and ECU.
Coding the ECU to the cluster was a pain. There are vast threads on the TDI club forums about this, so I won't go into it here. But one of the main things is that there must be no DTCs (Diagnostic Trouble Codes) and you must get the SKC (Secret Key Code) from the dealer.
I don't have ABS, and I don't have Airbags, so I'm guaranteed to have two DTCs in the engine computer. Plus, the local dealer refused to tell me my SKCs. Grrrr....
The solution: Christmas.
I took holidays over Christmas, and travelled back to Manitoba, the land of my people.
I took my key, ECU and cluster home for the holidays. Using my parents TDI as the donor car, I sweet talked my way into the back shop at a Winnipeg dealer. I did the wrenching, and they sent a tech over to do the coding.
Actually, they sent a tech-trainee over who had never done it before, but that's a different story.
Anywho, a piece at a time, coded my ECU to the other car, coded my cluster to my ECU, repinned the cluster connector to use my key reader, and coded my key to my ecu and cluster. Oooohhhh, magic.
Ok, so what next?
I did some investigation into keys and lock cylinders and such:
The Cabrio lock cylinder fits into the steering lock of my 1982 Rabbit. Cool.
Dave get's to use a switchblade key.
But I had to get a switchblade key cut to fit, as they aren't native to the Cabrio.
There are different kinds of IMMO keys. There are various types of fixed code and change code.
If you buy a G/JIV lock cylinder, it comes with "W" keys, and a permanently attached key reader, but it doesn't fit into the steering lock of the older cars. The switchblade key is a "W" key.
The Cabrio lock cylinder comes with "W3" keys, and you have to buy the key reader seperately.
The IMMO in the G/J cluster, connected to the Cabrio reader, doesn't recognize the W3 keys. It does recognize the W keys.
For my current setup, I'm using a cabrio reader, and a used W switchblade
key, buried up under the dash, with a 2002 cabrio lock cylinder for the
I don't know why the W3 keys don't work.
The W3 keys work with the cabrio reader with the cabrio IMMO box.
The W3 keys work with the G/J reader with the G/J IMMO,
but not with the cabrio reader and the G/J IMMO.
summary: IMMO3 is a pain
Part 1: Introduction
Part 2: Installing the Engine
Part 3: Transmission
Part 4: Wiring 1
Part 5: Speedometer and Cluster
Part 6: ImmobilizerIII
Part 7: Drive By Wire
Part 8: Intercooler
Part 9: Intake and Exhaust
part 10: MFA and Cruise Control
Part 11: The Dash
Part 12: The Little Things
Part 13: The End (for now)
Part 14: 6spd transmission and brake upgrades
One Year Later
Who Needs a VR6