Replacing ECU with IMMO-disabled unit from Reflect Tuning - what's required?

[jeffeverde]

New to Audi's and VAG-Com, so this is probably a dumb noob question, but-

I'm replacing my flaky ECU (bogus cam faults, fan running when engine off, etc) with a unit from Reflect Tuning (IMMO-disabled, Stage 1). I've reviewed the articles on R&R'ing the ECU, but I haven't found any tech docs on what to do after the replacement ECU is installed.


The little I've found about replacing the ECU talks about dealing with the IMMO. My replacement has the IMMO disabled, so that doesn't apply. So what else do I need to do? I understand that the ECU stores the VIN, so I assume I'll have to program the VIN into the new unit? (I've got Ross-Tech's VCDS, but haven't used it yet). Does the ECU decode the VIN to determine the engine details, or do I have to load other parameters? (stock '05 A4 Cabrio - no mods other than this tuned ECU)

Is there a tech doc that details the VAG-Com part of R&R'ing the ECU?

[Matt Devo]

the only thing that's actually required is to set the soft coding of the new ECU to match your old one. VIN setting can't be done via VCDS but isn't required for normal operation.

[walky_talky20]

If you wanted the VIN to match, you might be able to do the IMMO "used ECU swap" procedure anyway. Part of that procedure is to push the VIN from the cluster to the ECU. But whether it would work (or screw something up) would depend on how the IMMO defeat is done. That would be a question for whomever did the IMMO defeat.

But I wouldn't even bother. It would be unnecessary messing about with important things. As long as the car runs and the IMMO light isn't flashing, I'd leave it alone.

[diagnosticator]

If the fans are running with the car OFF, check for water inside the ECU box.

[jeffeverde]

the only thing that's actually required is to set the soft coding of the new ECU to match your old one. VIN setting can't be done via VCDS but isn't required for normal operation.

Would that be the "Software Code" section described in this Ross-Tech doc - Recode Module ?

[Matt Devo]

Would that be the "Software Code" section described in this Ross-Tech doc - Recode Module ?

correct. write down the code from your current ECU, then recode the new ECU to match.

[jaydeff]

With the immo defeated it should be plug and play with no extra steps required.

[blitz2190]

if you wanted it to be perfect you could copy your ecu's 95040 and write to the new one in boot mode. now your immo works and vin matches. But with immo off you will never notice anything wrong unless someone tries to steal the car ha.

[diagnosticator]

correct. write down the code from your current ECU, then recode the new ECU to match.

The ECU will learn the new VIN from the cluster by entering the Login code in login II, then going to channel 081 and entering the login code there again in Basic Settings. IIRC, the login II is 13682 or similar.