Help needed using DVT on a t42

[MyM8V8]

I was on the dyno today, but couldn't get anything done because of kick down into 2nd. I have a 4L65E on LS2 (E40).

I tried to get the DVT controls working and at first couldn't connect to the TCM. When it appeared to connect I used the appropriate buttons to hold 3rd, but nothing seemed to work.

I have a 4200 stall which could be part of the problem?

Any help or an idiot guide would be gratefully received.

It could be I haven't set the software up correctly as well.

[joecar]

You could try setting D0907 PT 3->2 downshift table to 256 mph all across... this would prevent the 3->2 downshift from happening.

Also set D0930 to 250 mph.

[MyM8V8]

Thanks for that Joe. I'll use that failing all else.

Being able to use the DVT feature would be great for other things too, so I must figure a way of getting it to work.
:help2:

[joecar]

In the scantool, goto DVT tab and select the controller as "Transmission 4/5 spd T42" and you will see the right buttons show up...

Then press Activate, and then checkmark Activate Transmission Gear Control and press Hold 3rd.

[MyM8V8]

In the scantool, goto DVT tab and select the controller as "Transmission 4/5 spd T42" and you will see the right buttons show up...

Then press Activate, and then checkmark Activate Transmission Gear Control and press Hold 3rd.

Yep. Did all that. The screen's quite intuitive.

Then a red colour bar comes up and says -can't remember what now but along the lines of- "sequential gear" whatever. I take to mean it has taken control of the box.

But it did not hold in gear. I also tried checking the 3-2 kick down with off button used.

[joecar]

It didn't hold 3rd gear...?


Do this: key on engine off, click the Hold 3rd button and see if you can hear the solenoid clicking.


The 3-2 downshift solenoid does not trigger the 3->2 downshift... it simply controls the apply rate of 2nd gear.

[MyM8V8]

Hi Joe,

I connected to the box in my workshop today. All nice and quiet. You can hear hear the solenoids click for hold on all gears except for third!

Not being a transmission man, what do I have to do? Is the solenoid available from the pan?

Would this be the reason why I am getting an overly big thump in the back when the TCC locks in 3rd (when in manual 3rd position)? What other problems is this causing with the functionality of the box?

Obviously the EFI Live is working great and I am rapt with finding so much more you can do with it..

Cheers - Gareth

[joecar]

Hi Gareth,

In 3rd both A and B solenoids are off...

they do make a sound when turning off, but sometimes it's very faint...

Do this quiet test:
- if you hear a click going from 3rd to 2nd, then the B solenoid is ok,
- if you hear a click going from 3rd to 4th, then the A solenoid is ok;

When you drive the car you are getting 3rd gear so the solenoids are ok.

The big thump when TCC applies (you're already in 3rd) may be just the TCC apply rate being quick causing a jolt which is taken up in the diff... is that what it sounds like...?

The TCM may be interlocking the bidir controls if mph|kmh are present...
see if you can find these tables: C6150, C6151, C6152.

Cheers
Joe

[Blacky]

Then a red colour bar comes up and says -can't remember what now but along the lines of- "sequential gear" whatever. I take to mean it has taken control of the box.

The red bar will display the error message from the TCM explaining why it rejected EFILive's attempt to control the gear. It is important to know what that error message said.

Sometimes the TCM has an upper RPM limit, which when exceeded, will terminate DVT and return full control to the TCM.

Regards
Paul

[MyM8V8]

Thanks Guys,

Joe, it looks as though the solenoids are working OK then, and I must find the reason DVT is rejecting 3rd hold. I'll have a look at the tables you mentioned.

I looked, I don't have these tables-Joe I am E40 with T42


Paul, IIRC we did move the RPM range up in the tune, however when the throttle is applied against the dyno I think the stall is flashing quite high and it changed down.

I might try locking the TCC first -the manufacturer did say it was unbreakable!

It could be that I have a mechanical issue with the stall or gearbox or both.

I'll see if I can replicate the error message -and write it down!

Cheers.

[MyM8V8]

Just been out on deserted roads and tried again.

Holds in each gear while on the road.

Also used the TCC locking feature (Not recommended at at rest!!!).

I found that to use this on the T42, you had to tick and turn on TCC lock button first, then hit the TCC enable button second for it to lock.

I imagine the problem I had on the dyno was to do with my very loose stall.

Next time I will: 1. Press Hold in 3rd button. 2. ( Disable 3-2 kickdown),
3.Tick and press TCC lock button, tick Enable TCC box, build up rpm and then hit ENABLE (TCC) button. I reckon that should work.

Any other advice gratefully received.

[joecar]

Yes to lock the TCC you have to activate both TCC solenoids on the 4L60E (the 4L80E only has 1 TCC solenoid).

The 3-2 solenoid only controls the 3->2 accumulator fluid exit... it doesn't do a 3->2 downshift... so it won't matter what state you command the 3-2 solenoid.

[joecar]

IceBox wrote:I think ScriptDoc and CodeAssist are not based on the same approach. However it is a guess.

Is your issue "oEvent" is not code assisted as an Event object?

Regards,
IceBoxCome again...?