Help with 4L80E

[flak monkey]

Finally got my fresh motor and transmission installed in my Camaro. But I have a few issues....

I've attached a datalog and my current MSQ. The VSS is set wierd because I am using a DRAC. I still have yet to figure out the correct settings, but it's sort of working enough for testing.

The car has the rear wheels off the ground in these tests....

This is a 1994 4L80E behind an LQ9.

When shifting into drive, the input switch patterns don't seem to change, the datalog shows me manually shifting through the gears using the selector.

I shift from N to D at 188 sec, the input switches don't change. Then there are other shifts, down to 1st then back up.

The other shifts look a bit screwy too. I'm about to check my wiring, any other suggestions?

Also I notice that my input shaft RPM doesn't seem to be working? Stuck at 418rpm throughout. What could be causing this? I've noticed it does change sometimes, but not as you would expect.

My speedo also doesn't work...

[Bernard Fife]

When shifting into drive, the input switch patterns don't seem to change, the datalog shows me manually shifting through the gears using the selector.

flakmonkey,

As long as the gear indicator shows the current shift lever position correctly, that it what is important. It means the code is seeing the correct input signals, even if these aren't being reported in TS (you could look at the input 1/2/3 voltage signals in the gauges to see what they are reporting). The input indicators have given trouble before though, and there may be something wrong there, so I will have a look when I get a chance.

Do you have your input shaft sensor hooked up properly? Did it work on the stim? If you don't have a stim, have you tested the ISS input circuit (VR3 to PT5) another way? There are a number of tiny leads to solder on the transistors, and it's easy to bridge these accidentally.

[flak monkey]

Hi Lance, thanks for the quick response.

I found I had missed one of the jumpers off the input pins - fitted that and it's OK now.

This is the first time I have had the controller connected to the transmission, I don't have a stim.

Took another datalog with the inputs working correctly this time - attached. I noticed my ISS started working toward the end - no idea why, as it's stopped working again now. The sensor is a new one, I pulled all my wiring out and checked that and it's all OK too.

The other thing I am not sure of is whether it's actually shifting or not.

If I put the lever in any position from 2 to D and give it some throttle to bring the speed up past the shift point I can't feel it shift at all. (See datalog). But if I put it in manual 1st then I can feel and hear it shift, then shift up when I put the lever in 2. But it doesn't shift past that....

The current gear seems to report either 0 or -1 (in reverse). Se datalog...

Reverse seems to work - at least the wheels rotate backwards

Not really sure where to go next. The transmission is newly built, although I reused the original solenoids, so perhaps there is a duff one? But then if it will manually shift to 1st, why doesn't it start in first then at least shift to 2nd?

I have about a week's worth of work to do before the car is ready for the road...

[flak monkey]

Also, not sure what the spare port functions should be set at - I'm not using any as far as I know?

Aaand - when you set the 4L80E as the transmission type it sets the output solenoids as the attached photo. This is different to the picture at the bottom of this page, though as 'Output 3' isnt used with the 4L80E I expect it doesn't matter?

http://www.msgpio.com/manuals/mshift/4L80E/4L80e.html

output solenoids.JPG (218.85 KiB) Viewed 13240 times

[flak monkey]

Anyone?

Looking at the datalog it seems that the gear indicator isn't working - other than in reverse. And I assume this is what is stopping the transmission shifting?

No idea why, as everything else is working OK. I might try re-loading the firmware tonight and then seeing if it works. Otherwise I am at a loss.

[flak monkey]

Reloading the firmware and msq made no difference.

[gui67]

HEllo,

I would try do not force RPM check during the tests.
And also, try to make the sensors ISS and OSS work, or at least VSS: ISS is not needed if you have the RPM from CANbus.

here is a datalog from my friends 4L80e, if you want to see what should happen.

2016-04-02_15.58.47.msl

(2.64 MiB) Downloaded 531 times

I don't think current gear should stay at 0 when the manual gear is at 4. This is what happens in your datalog.

[Bernard Fife]

I don't think current gear should stay at 0 when the manual gear is at 4

It might if the VSS is zero (or otherwise screwed up). The VSS is the single most important input - is must be right. So get that working first; here's some hints: http://www.msgpio.com/manuals/mshift/vss.html

Then the manual lever inputs need to reflect the actual position of the shift lever. In your case, we don't know if that's because of the input voltage signals themselves are as designed, or perhaps the GPIO circuits aren't working to spec, or maybe the code isn't configured to match your input patterns, or it's possible there's a problem in the code (but the previous issues are more likely).

Here's a plan for testing a new installation: http://www.msgpio.com/manuals/mshift/test.html

But since you haven't checked the board on a stim, we really can't say much about what might be the problem. Input values that are out-of-range can cause all sorts of problems in the code, and this can freeze things, etc. So you need to make sure the inputs are correct and reflect the physical inputs AND that the outputs are responding correctly. The best way to do that is with a stim. There are other ways, but they require a lot of thinking and more testing equipment (see the link I gave above).

[flak monkey]

The VSS is working fine in the second datalog. I had to change settings as I am using a DRAC so the PPM are different. It's the ISS that doesn't work.

The switches are also working fine in the second datalog, they match the lever position as I shift through the gears.

Current gear only changes in reverse, otherwise it stays at zero. How does the controller determine this? Just the switches?

I pulled the controller out of the car last night and looked over the board. Checked every component value and all solder joints, everything looks ok.

Getting a stim is going to take me a couple of weeks by the time the board arrives from the USA. This is holding up getting my car back on the road now

[flak monkey]

HEllo,

I would try do not force RPM check during the tests.
And also, try to make the sensors ISS and OSS work, or at least VSS: ISS is not needed if you have the RPM from CANbus.

here is a datalog from my friends 4L80e, if you want to see what should happen.

2016-04-18_15.45.24.msq

(61.85 KiB) Downloaded 739 times

I don't think current gear should stay at 0 when the manual gear is at 4. This is what happens in your datalog.

I don't understand why the gear indicator doesn't work consistently.

Pressure switch inputs are OK, and the patterns are OK compared to the manual.

I used the 4L80E msq you posted for me a couple of weeks ago and just changed the PC solenoid frequency and the speed bins on the tables. Nothing else.

I'll try again tonight, after that I have to wait for parts to arrive.