Memory dump of ECU

[b3lha]

Originally Posted by Trevor

As a result of this post I will no doubt again be accused making an attack, but so be it. Incorrect information is not in the interests of members and requires correction. This particularly applies in respect of the arduous work covered by this thread.

Thanks Trevor. I do not read your post as an attack, merely a differing opinion. I asked Harvey to post here because I value his opinions. I also value yours and those of anybody else you wants to chip in.

Originally Posted by Trevor

Solenoid valves 1, 2, & 3 are normally open devices and close and shut off fluid when energised (electrically turned on). In this state they do not bleed off pressure and close the bleed so that pressure is applied.

These normally open solenoid valves are turned ON in order stop pressure bleed off and as a result then provide control pressure in respect of the selection of ratios 2, 3, & 4.

Solenoid valves A, B, & C, in the case of transmissions incorporating a centre clutch, are all normally closed devices. Solenoid valve C is a normally open device in the case of transmissions incorporating a centre differential.

In regard to this project, I don't see that how the solenoids operate is important. That subject has been done to death a few times already. The information I am looking for is why the solenoids operate. What is the TCU trying to achieve when it increases or decreases a given duty cycle. What is the nature of relationship between, for example, the solenoid C duty cycle and the torque split.

Originally Posted by Trevor

Thus in both systems the respective C Solenoid valve is near fully energised for virtual lock up of front rear, without requiring a different configuration of electrical or hydraulic systems. Both C valves bleed off fluid as a means of control.

That's the sort of thing I'm looking for. On my car, with the JDM box, when the stick is in N, solenoid C is at 5% duty. On Nomake's car, with the USDM box it is 95%.

I don't know how the duty cycle relates to torque split on the JDM box.

On the USDM box, Nomake is assuming that 95% is FWD because it starts out at 95% and drops on hard acceleration when the TCU is presumably transferring power to the back. You seem to be suggesting the opposite. This discussion is certainly worth having.