Gear changes stopped working?

A forum for discussing applications and implementations of the MegaShift transmission controller code for the GPIO from B&G. This can control up to 8-speeds and 6 shift solenoids (plus a 16x9 table for controlling a PWM line pressure valve). It has manual and fully automatic modes (16x9 load x speed table), with under and over rev-limit protection, and full data logging of all inputs and outputs (among many other abilities). A TransStim to test your completed board is also available.
Post Reply
shaodome
Posts: 58
Joined: Thu Aug 22, 2013 6:28 am

Gear changes stopped working?

Post by shaodome »

So I was driving the car today and everything was fine for about 20 minutes then out of nowhere it didn't want to shift gears anymore. The current gear always stayed at 1 regardless of what the manual gear was or the trans tables were.
Attachments
3_CurrentTune.msq
(45.21 KiB) Downloaded 563 times
won't change gears.zip
(318.84 KiB) Downloaded 648 times
shaodome
Posts: 58
Joined: Thu Aug 22, 2013 6:28 am

Re: Gear changes stopped working?

Post by shaodome »

I know the trans temps were high on the above (the cooler isn't big enough) so I was trying to get it home and couldn't get it to get out of first gear.

Now...after it cooled off, it's fine again!!!!????
shaodome
Posts: 58
Joined: Thu Aug 22, 2013 6:28 am

Re: Gear changes stopped working?

Post by shaodome »

Anything on this?
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Gear changes stopped working?

Post by Bernard Fife »

shaodome,

What do you see happening in the log? Is there anything that doesn't look right? Was the VSS value acting up? Are there error codes? Does the manual gear lever value do anything unexpected? How does the current gear compare to the target gear and manual gear? Was the trans still in auto mode, or was it in manual mode (even if you didn't deliberately put it there)? Was the speed too high for a shift from first because of rev limiting? You were the one driving the car, and you know best what was going on (in terms of the things that aren't in the datalog) so you are the best person to make the initial assessment of the datalog then I can help with more specific details about how the code works (and how it should work).

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
shaodome
Posts: 58
Joined: Thu Aug 22, 2013 6:28 am

Re: Gear changes stopped working?

Post by shaodome »

Lance wrote:shaodome,

What do you see happening in the log? Is there anything that doesn't look right? Was the VSS value acting up? Are there error codes? Does the manual gear lever value do anything unexpected? How does the current gear compare to the target gear and manual gear? Was the trans still in auto mode, or was it in manual mode (even if you didn't deliberately put it there)? Was the speed too high for a shift from first because of rev limiting? You were the one driving the car, and you know best what was going on (in terms of the things that aren't in the datalog) so you are the best person to make the initial assessment of the datalog then I can help with more specific details about how the code works (and how it should work).

Lance.
You can see the behavior in the log. The manual gear is 4, the trans is in auto mode, the speed is working perfectly now, but current gear remained at 1.

The error field says 1.0, but I don't know what that is referring to. It says 1 in other logs where the car shifted fine.

Rev limit checking was disabled, and even if that was the case a power cycle would have wiped that.

I was driving the car and flogged it a little then was cruising home and half home on the cruise (via local streets, so stop n go) it just stopped shifting out of first gear.

The car was in auto mode (Mode =1) according to the log.

What I find very strange was after letting the car sit for a few hours, I came back outside and it shifted as normal, with nothing changed other than temperature of the trans/engine. The trans cooler definitely wasn't up to the task so it was on the hot side.
Post Reply