D2 S8 AQH (ME7.1) ECU Vs C5 S6 AQJ (ME7.1) ECU

[Nollywood]

Any ideas, anyone?

[tc4332]

Too techy for me, sorry.
Good luck though

[Goran]

I have no idea, except for following curious differences:
S6 40V 4.2 produces 335hp, is it just de-tuned or is there a mechanical reason for this?
S6 40V 4.2 has and electric fan instead of the viscous fan, would this different coding be reflected on its ECU and would it result in a different pin-out?

[MikkiJayne]

Originally Posted by Nollywood

This soft coding only prevents the automatic ECU from looking for the absent TCU, thus not throwing a CEL. It does not however improve drivability, or prevent the rpm from being too high at idle, or allow the rpm to drop quickly or smoothly between shifts.

I'm curious how you know this? Have you tried it? I would have expected the soft coding to change the software it uses, not simply deactivate the TCU.

Originally Posted by Goran

S6 40V 4.2 produces 335hp, is it just de-tuned or is there a mechanical reason for this?

It is mechanically identical, even down to the injectors. The S6 has a second solenoid attached to the front of the manifold which activates something off the engine, but it still has a single-stage flap activation. The difference in power output is purely software.

The electric fan is probably a separate circuit, the same as the S8 and B5.

[Nollywood]

Originally Posted by MikkiJayne

I'm curious how you know this? Have you tried it? I would have expected the soft coding to change the software it uses, not simply deactivate the TCU.

Yes, I have tried it on 2 different cars, even with the clutch switch wired in.

Originally Posted by MikkiJayne

It is mechanically identical, even down to the injectors. The S6 has a second solenoid attached to the front of the manifold which activates something off the engine, but it still has a single-stage flap activation. The difference in power output is purely software.

The electric fan is probably a separate circuit, the same as the S8 and B5.

The S6 motor is mechanically similar to the S8, the S8 has a more aggressive intake cam, more lift and duration. Pistons are the same, heads are different. Both run the same dual-stage intake, same as the D3 4.2, which shares cam shafts with the S8, I can't remember which.

[Nollywood]

I've ordered a manual S8 ME7.1 ECU (AQH) from TPS.

[nakata]

Originally Posted by Nollywood

I've ordered a manual S8 ME7.1 ECU (AQH) from TPS.

On which car you want to install it?
I'm done it many time this procedures, sorry but just now see the thread.

[MikkiJayne]

Originally Posted by Nollywood

The S6 motor is mechanically similar to the S8, the S8 has a more aggressive intake cam, more lift and duration. Pistons are the same, heads are different. Both run the same dual-stage intake, same as the D3 4.2, which shares cam shafts with the S8, I can't remember which.

Inlet cams are the same part number (077 109 012FR) for all the 40V 'S' engines - AQJ, ANK, AQH, AVP and BCS, ditto the cylinder heads. I've yet to find a single difference between the S6 and S8 apart from the mounts. I spent a lot of time researching that before buying a new AQJ to replace my sick AVP

The AQJ and AVP definitely have a single stage manifold. Two flaps, two actuators, both plumbed in to the same solenoid via a T-piece. I'll post a pic later. The manifold looks the same, but both sets of flaps are activated together. The wiring diagrams show the same iirc - two solenoids on the 'A' engines, one on the 'S'.

I would have suggested loading the manual software on to an auto ECU, but I guess its too late now!

[Nollywood]

There are lots of different files floating around for the manual S engines, and the results in terms of drivability vary. I had to replace my ECU regardless, as it is ME7.1.1. The cost of used is at least 50% of the cost of new (exchange). Besides either coding the immobiliser out, or programming my keys to the new unit, and enabling cruise, it's plug and play.