Thread: Auto trans no second

Originally Posted by thai_tiger

Hi all, looking for pointers before i get started please.

Auto trans has lost second gear all other gears including reverse are fine even goes into lockup correctly. Stall test comes up good and within speck

Select D pulls away in 1st but will not change up until 60+ klms when it hen goes into 3rd and acts normally after that

Nanocom showed no faults.

Any tips appreciated

What happens if you manually select 2nd?

Originally Posted by shack

What happens if you manually select 2nd?

Manually selecting second does the same goes into 1st then nothing just holds 1st as if 2nd has been deleted

With your nanocom, you can view the solenoid states.

Solenoid 1 and 2 are gear solenoids, 3 is for the lockup clutch in the converter.

I can't remember what the states are for each gear, but if you start off in 1st and watch the solenoids on the nanocom, you should see states change as it tries to select another gear.

Watch this to see if solenoids change but no noticeable gear change happens.

That will tell you if it is trying to change or not.

Report back and we can go from there.

You can check what version TCU you are running with the nanocom, of you find that can you post it back here please.

Cheers

Interesting thread. James, can the Nanocom record the solenoid activity?

Good luck with it t_t.

Originally Posted by Tins

Interesting thread. James, can the Nanocom record the solenoid activity?

Good luck with it t_t.

Yes it does John.

If you physically can't feel the shifts but the solenoids are showing on the nanocom that they have been activated, it gives you somewhere to start.

My guess would be valve body problems, I was thinking sissy a solenoid issue, but that would stop other gears as well.

And lastly a failing TCU.

The last one is not likely but it's certainly possible, I've seen one.

The only thing with the failing TCU is that the firmware is pretty tightly checksummed, so if something becomes corrupt, it should throw a fault.

There could be a physical problem with something on the PCB though.

Thanks, James. I don't want to hijack t_t's thread, but am interested as mine seems to hold second longer than I like. I don't mind it when the car is cold, but it seems to be happening when it warms up. (I'm going to change the oil back to TransMax when I'm fit enough to get under it. Needs a filter change anyway.) So I'll record a log.

Originally Posted by Tins

Thanks, James. I don't want to hijack t_t's thread, but am interested as mine seems to hold second longer than I like. I don't mind it when the car is cold, but it seems to be happening when it warms up. (I'm going to change the oil back to TransMax when I'm fit enough to get under it. Needs a filter change anyway.) So I'll record a log.

If you record a log from the Auto Trans section and send that to me or post it back here along with your TCU revision (you can retrieve it with the nanocom) I'll take a look.