Transmission Closed throttle shift and power downshift

[4wheelinls1]

I have a number of vehicles with the same issue. They are all conversions and all early E38 OS. I have tried different transmission OS that are acceptable to the early 6L80e. I have tried 2008 and 2009 ECU's with different operating systems. I have logged a ticket with HP who claim there are no additional shift tables yet these cars all log both power downshift and closed throttle downshift when downshifting at cruise speeds. The shift is not commanded in any table. Some vehicles have a BCM, some a CAN interface so TUTD will work. I thought it may be due to the brake pedal position switch missing but with no brake logging I still have undefined downshifts.

I know of others who have had this issue and have upgraded to later OS, but to do that is an expensive option with an early transmission.
I have multiple logs from 2 vehicles and another two that have come to me tuned elsewhere looking for a solution. There are clearly other shift tables or a closed throttle downshift and power downshift option on closed throttle but I can't get HP to look into it any further.

Any ideas would be much appreciated

Shifts unrelated to shift command.hplNormal pattern set low .hpt

[hjtrbo]

I can take a look at the binary.

In your log at 2min 6sec I presume that's an example of the issue?

[4wheelinls1]

I can take a look at the binary.

In your log at 2min 6sec I presume that's an example of the issue?

Yes and at 42.6

In this log in the first 45 seconds there are multiple downshifts due to power downshift at cruise throttle. The downshifts were all set to 0 when this was taken.


POwer downshift light throttle all downshift patter 0.hpl

Thanks

[hjtrbo]

There's some stuff in there like abs forced downshift etc that looks at output shaft speed. Can you out a ticket in to get that channel working. It's usually a couple of weeks.

Can you double check your settings for diff ratio and tyre revs in the Speedo tab. That should all match.

The first log has a nasty DTC logged. Can't remember the number but it's complaining about a ram error. Has that been addressed?

[TransGo Robert]

I doubt it will fix it, but I see the DTC in there for Crankshaft position Not Learned, you might want to do the relearn just in case.

Also, you guys talk about a first log with the issue happening at the 2 minute 6 second mark, but I must be blind I only see the log that just got posted 20 hours ago where it goes 5-6-5-6-5-6 for the first half of the log. Did that log got removed from the thread somehow?

[gtstorey]

You have to look close at the attachment in the first post. It has both a log and a tune.

[TransGo Robert]

You have to look close at the attachment in the first post. It has both a log and a tune.

Son of a gun I am indeed blind!

Thanks.

[hjtrbo]

Yes and at 42.6

In this log in the first 45 seconds there are multiple downshifts due to power downshift at cruise throttle. The downshifts were all set to 0 when this was taken.

Thanks

Holy shit, that's off it's head. I'm still poking around the bin. The shift logic is not as simple as I'd hoped I.e. km/h > shift speed. They've got modifiers to it, decel delay, anticipation logic, altitude and temp correction and a tonne of overrides. Good little project.

Please do the things Rob and I have asked.

1. Crank relearn
2. Diff and tyre size matching
3. Ticket in to support for output shaft speed

[4wheelinls1]

I doubt it will fix it, but I see the DTC in there for Crankshaft position Not Learned, you might want to do the relearn just in case.

Also, you guys talk about a first log with the issue happening at the 2 minute 6 second mark, but I must be blind I only see the log that just got posted 20 hours ago where it goes 5-6-5-6-5-6 for the first half of the log. Did that log got removed from the thread somehow?

I haven't been able to do a crank relearn due to it being a conversion, needs to see handbrake I think.

[TransGo Robert]

I haven't been able to do a crank relearn due to it being a conversion, needs to see handbrake I think.

Got it, probably not related to your issue anyway but you never know.

[hjtrbo]

ok. If you can make the changes I mentioned to diff / tyre size.

Can you please confirm the shifter position in your 2nd log. I.e. drive, sport, tutd.

[4wheelinls1]

ok. If you can make the changes I mentioned to diff / tyre size.

Can you please confirm the shifter position in your 2nd log. I.e. drive, sport, tutd.

The values are correct, the vehicle is a Landcruiser. Shifter position is normal mode. (I did try all modes including hot mode) I did initially think the issue was due to the absent Brake pedal switch, we have tried wiring to the ecu but there is also an option to wire to the trans, with the BCM fitted it would indicate the brake pedal was applied, since fitting the CAN adapter the Brake pedal logs not on so that canned that. This issue is in 4 vehicles I am aware of, all converted, all early OS. Odly I have one that does not do this using the same OS and CAN adapter.

The Vehicle attached drives normally, if there is something that can be seen different I've. I used all the OS from the vehicle that does not fault which did not resolve the issue.
This vehicle was not switching fans but I suspect it was in the wiring. Again this is a 4x4 conversion.

possible fault due to fans switching not through ecu.hpt

[hjtrbo]

Ah conversion, that increases the hay stack size. What is different in the vehicle that does not have this problem compared to the other vehicles? There has to be a clue there.

What is the can adapter? I'd like to take a look at it.

I insist on you getting the diff / tyre values matching. Even if it doesn't fix your issue, it's ticked off the list.

[hjtrbo]

Another thing to look at is set the TCM 461 Pattern Type B back to stock (which might be cruise? You'd need to check that). This could well be your issue, I know from what digging I've done if the pattern types are changed you push the shift table look up pointer to a table addresses that is either not mapped or is one of the obscure shift types like safety shift etc.

Failing the above and my post before this one; what happens if you use the same hardware in the good vehicle and with the last tune you posted 'As Is' and write entire both ecm and tcm on the vehicle with the fault?

Some of the stuff that has me confused as to why it would need changing if these swaps are the same...

[4wheelinls1]

Another thing to look at is set the TCM 461 Pattern Type B back to stock (which might be cruise? You'd need to check that). This could well be your issue, I know from what digging I've done if the pattern types are changed you push the shift table look up pointer to a table addresses that is either not mapped or is one of the obscure shift types like safety shift etc.

Failing the above and my post before this one; what happens if you use the same hardware in the good vehicle and with the last tune you posted 'As Is' and write entire both ecm and tcm on the vehicle with the fault?

Some of the stuff that has me confused as to why it would need changing if these swaps are the same...

I don't have the car ATM but I will get it, you may be onto something with the diff ratio as in the car that does work is all set the same. I used the wizard to set it up so perhaps it hadn't filled all the values?

Those differences may have been me trying all sorts to get a result, and then me calibrating the speed with compare copy and possibly moving the problem from one car to another? The vehicle when it came to me had mismatched everything, I had the BCM, trans and ECU programmed to match so the TUTD would work. After numerous attempts at solving this issue having two cars that did this and one that didn't I then got a 2009 ecu and updated the problem car to the same OS as the non-problem, as that did not work but we then changed the BCM out for the CAN device. The supplier is an Ex-Gm guy. Overline Technology. I will get the car and try the settings as suggested.

I did try changing the pattern select and also did all shift maps the same at one point as I did think it may be cruise control doing something funky due to the BCM or ABS having no inputs.

Thanks.

[4wheelinls1]

[QUOTE=hjtrbo;790506]Another thing to look at is set the TCM 461 Pattern Type B back to stock (which might be cruise? You'd need to check that). This could well be your issue, I know from what digging I've done if the pattern types are changed you push the shift table look up pointer to a table addresses that is either not mapped or is one of the obscure shift types like safety shift etc.

Failing the above and my post before this one; what happens if you use the same hardware in the good vehicle and with the last tune you posted 'As Is' and write entire both ecm and tcm on the vehicle with the fault?

Some of the stuff that has me confused as to why it would need changing if these swaps are the same...


I never noticed this.

Crazy values?

Tyere revs 155447.png

[4wheelinls1]

[QUOTE=hjtrbo;790506]Another thing to look at is set the TCM 461 Pattern Type B back to stock (which might be cruise? You'd need to check that). This could well be your issue, I know from what digging I've done if the pattern types are changed you push the shift table look up pointer to a table addresses that is either not mapped or is one of the obscure shift types like safety shift etc.

Failing the above and my post before this one; what happens if you use the same hardware in the good vehicle and with the last tune you posted 'As Is' and write entire both ecm and tcm on the vehicle with the fault?

I did start with a straight swap, spark, fuel, engine size, VE that stuff only but also speedo so maybe that is the isssue. getting the car Sat to test.

[hjtrbo]

Good. I'm not familiar with swaps. Some of your settings may be necessary so I'm not all over what's required. Did you by chance tune a swap in a Landcruiser shorty for Steve at Warragul Exhausts? And does your last name start with B? PM me if you want to keep it on the down low, I know of you.

[4wheelinls1]

Good. I'm not familiar with swaps. Some of your settings may be necessary so I'm not all over what's required. Did you by chance tune a swap in a Landcruiser shorty for Steve at Warragul Exhausts? And does your last name start with B? PM me if you want to keep it on the down low, I know of you.

Yep that's me. I tune around, mostly referral and remote support, a couple of shops as well that only do low volumes.

And the solution was in the detail. I set all the calibration and tested which made no difference, but the settings here did. many thanks for the input. Apparently, I copied the problem along the way.


Trans settings.pngTrans settings.png

[hjtrbo]

Beautiful thing. You helped me many years ago get to the bottom of non functioning tcc reg and offset scalars. You got the tcc desired pressure table defined for me. I've actually been wanting to get in touch with you since I last caught up with Steve. Will make an effort during the week. Cheers, Nathan P.