Vehicle Speedo correction issues E38/T43

[Hooter]

Hi Guys Ive searched high and low through here on this topic, and I read somewhere that speedo correction cant be done correctly
I have a VF L77 and 6L80 in a VS Commodore ute.
I can do what Im trying to do here easy when doing LS1 conversions and using LS1 OS
It appears that I can only change the general VSS stuff and get the speed in the scantool to match my GPS, but the trouble is, when actual speed is say 80kph, my VS speedo only reads 30kph. I can change this globely, but obviously I need my ecu speed to be accurate for my gear shift points, and it seems the fine tuning doesnt work at all with this OS.
I realise I can add an electronic adjuster to my speedo, but does anyone know how to adjust without that
I have speedo set as serial data, which is the only setting it will work on, and flick shows the rest19182

[Hooter]

Is there some way I can bump up the speedo output from the ecu to speedo, without upsetting the ecu speed... anybody know???
I tried a Jayar speedo corrector yesterday, and at the max setting, I can now get it to within about 10%
I realise I can change the global speed so that the speedo will show correct speed, but at the expense of the ecu speed being nearly doubled, which will mean a complete revamp of all my A6 trans speeds amongst other things.......
Anyone got any better ideas or a fix please???

[Hooter]

I'm not sure what to say here without criticizing someone or something, or whether its just me.....
This E38 software has a lot left to be desired....
The problems I'm having are a snap with LS1 stuff.....
So here's where I'm at
I reduced H0105 from 481 by 50% to 253 because I know this effects Scantool speed and actual speedo speed, so this combined with my speedo corrector set at 50% actually gave me a very close reading compared to my GPS, except the scantool was reading way high......
I thought this would mess up my shift point speeds but they remained the same..... wtf..???
So.... I thought this is pretty cool.... so I dropped H0105 another 20% and zeroed my speedo corrector, and bingo speed was now very close...... except, my scantool was even worse higher, and when it reached 160, I got speed cut, which was actually at 65kph....., so I changed this back to previous settings, and still got speed cut at 160kph although actual speed was now 80kph.... time to check other things
Then I noticed Speed limiter comms failure H0131 is set to 160, so i will max that out and try tomorrow, as it is late now and a couple of rums to numb things....
Blacky, Ross, Ian, Taz, am I barking up wrong tree????
Is there a variable that splits scantool versus speedo (as does the speedo fine tuner in LS1), or is it part of the protocol, and the design of the E38 that prevents this??
I know that the VR VS auto pcm has a similar issue where ppk or mph factor does not effect displayed speed, but changes shift speeds correctly, and you just have to live with that and work off you actual speed, similarly here....
H0105 effects scantool and actual speedo, but has no effect on shift points, so you can still tune your shift points from your speedo or GPS, but cant log speeds with scantool.
I can work with this if the Comms failure speed cures speed cut....
I can test all this stuff for you, as this is the purpose of this exercise with the conversion of the VF L77 and 6L80 into the VS ute to begin with so that I can nut out most issues for others doing these conversions (which is huge) as I make the wiring harness conversions and tuning here in WA, and Im sure the eastern states guys are interested in this too......
Cheers Al

[Taz]

... it is late now and a couple of rums to numb things ...

Now that is funny - those years are far behind me.

No Holdens sold here - so I don't completely follow what you are attempting with the VF or VS references.

I believe the L77 was released in 2010 ?

I take it a VS is an older vehicle ? Did it originally use an LS1-B PCM ?

Are you using E38 and T43 tunes from the same vehicle ?

Post your tunes when you get a chance.

[Hooter]

Hi Taz, I thought you may be Tasmanian....
VF Commodore is latest and current model and sadly the end of production lines for Holden... thanks to GF meltdown.....
VS ran from '95 to 2000 and was pre LS1 here in Oz....
How do you attach files here??? duh...

[Tre-Cool]

VF is the latest model commodore, VS is pre LS1 engine. so it's OLD. it used ALDL comms.

On a slightly related topic, I'm planning on trying to put a e38/t43 combo in a vy ute. but i'll be using a vz pim module to translate can data into aldl signal for the dash cluster.

Would this be something you could try in the vs?

[Hooter]

Yeah the VS used Uart serial data, but dash was not controlled by BCM, and is just old school.
Interestingly I cant get Tacho to work either, Ive also had a remote tacho on it and also no go...
I will have to scope X1-48 to see if there is signal.
Now the update, Changing the speed limit comms failure H0131 to max fixed speed cut at 65kph ( 160kph on scantool), so i now have speedo spot on with H015 set at 200, but VSS on scantool is reading approx 100kph higher....... anyway the good news is, this doesnt effect A6 shift points
I converted a Vz V6 to VZ Ls1 last year.... what a headf$%k... but i got it, and changed PIM modules, and even got cruise control to work
As far as i know Im the only clown that has done this, by modifying (probably worked out a $2.50 per hour... lol).... others have done it by swapping whole body harness etc from complete donor car....
VZ V6 has a Can bus PIM also ( I havent compared VZ E38 type to V6 yet)..., so I was concerned that the 2 different PIM's would output speak the same Class 2 serial data... It did so all was good... kinda like converting German and Swahili to English.... with maybe different meanings........ kinda like late friday nights at the local....

BTW, the lighter VS ute is awesome with the 6L80, fits right up to original rear crossmember using CAE front mounts and headers, and could have used original 5L 4L60e transmount as it was a perfect fit, but didnt have the safety tab, so I spaced up the VF mount as it does has the safety tab, and at that height the donut type tailshaft lined up perfect with the centre bearing, so this should work in the VY/VZ as well. If the VY/VZ 4L60e transmount is different to VS, you may be able to use yours.....
I used 3.45 gears with Truetrac.... Im thinking now I could have left it at 3.08, as it is in 3rd gear within first 50m...., great for skidding, but doesnt put it down too well, but has great decel compression braking...

[Taz]

... VS ran from '95 to 2000 and was pre LS1 here in Oz....

Were these OBD-1 ?

Or OBD-2 with some type of Black Box PCM ? Everything in North America had to be OBD-2 compliant beginning in 1996.


... How do you attach files here??? duh...

When you log in to post - click the "Go Advanced" button - I believe the image of the paper clip is the file attachment button.

[Taz]

VF is the latest model commodore, VS is pre LS1 engine. so it's OLD. it used ALDL comms.

On a slightly related topic, I'm planning on trying to put a e38/t43 combo in a vy ute. but i'll be using a vz pim module to translate can data into aldl signal for the dash cluster.

Would this be something you could try in the vs?

Thanks Tre-Cool. The only North American vehicle that I can think of that may have used a PIM (Powertrain Interface Module) was the GTO - but these were only sold in the USA - have never worked with one.

Do you only need the PIM in your future conversion project to translate CAN Bus communications to Serial Data communications, or do you need it for other functions ?

The E67 (with a Trailblazer, H3, or Colorado calibration) will output Serial Data to the gauge cluster (IPC). Perhaps using an E67 in your conversion would alleviate the need for a PIM ?

[Taz]

... I cant get Tacho to work either, Ive also had a remote tacho on it and also no go...
I will have to scope X1-48 to see if there is signal ...

You will need to add a pull-up circuit to get it to drive the Tach. Lots of information on how to do this already on the internet.


... I used 3.45 gears with Truetrac.... Im thinking now I could have left it at 3.08, as it is in 3rd gear within first 50m...., great for skidding, but doesnt put it down too well, but has great decel compression braking...

The 6L80/90 have a deep first gear ratio - they work well with axle gears in the 3:1 range - in lightweight Hot Rods or even in light duty two wheel drive trucks (as long as there is a 6.2L under the hood !).

[Hooter]

Here are the tunes
Ive attached the originals as well so you can compare
Ive done minimum mods yet as it runs pretty well as it is, and also I cant put on the dyno yet without having TUTD connected
Im hoping to get this done later today
19196191971919819199

[Tre-Cool]

Taz, the pim module is same as what they used on the gto models (both 5.7 & 6lt), for the local vt-vz range the dash (IPC) still used aldl comms (8192 baud) as i suspect due to holden wanting to keep the same body harness for the v6's which had the old comms stuff for the ecu still.

I think it's probably like the serial comms you guys get in the usa but old as hell. it's also used for the bcm/srs to talk to the dash & ls1 for check engine light/low oil pressure signals.

late vz models went to the e38 along with e40 (only in the hsv's and export gto's) so they used CAN but still had to talk back to the dash cluster in aldl. as such there is 2 types of pim's. 1 does ls1 serial? to aldl the other is can to aldl.

http://pcmhacking.net/forums/viewtopic.php?f=10&t=219

While the vt-vz dash clusters can have the rpm/tacho wired directly in from the ls1 ecu, you wont get coolant temp/oil pressure warnings and a bunch of other stuff. So for the sake of some additional wiring i've added bcm's & pims to both of my drag cars. it saves having to add additional sensors/gauges.

Hooter as for the tapshift, i've got one these but i havent used it as of yet.
http://www.eficonnection.com/eficonnection/ItemDetails.aspx?ItemId=1050

[Taz]

Tre-Cool ... Thank you for the explanation - it sounds like Holden didn't do you gents any favours during the transition from OBD-1 to OBD-2 vehicles.

Hooter ... Thank you for posting the tunes ... what is the rear axle gear ratio and tire size (i.e. P235-75-15) in the conversion you are working on ? Once I get this information, I will post a new E38 tune for you to try - that hopefully fixes the Speedometer / VSS issue.

[Hooter]

My Axle ratio is 3.45 and tyre size is 235/40x18
Interestingly I changed my scantool over to read the T43 which is another (very frustrating) story in itself.... and the VSS speed there is correct, where in the E38 it reads approx 120% higher, but I have the actual speedo correct now.
Also I put a 10k pullup resistor in the tacho input and that is now good, with the G1202 and 1203 both set at 8 .

Ive always had issues with my scan tool with E38 stuff, and often if I add certain PID's, I get really berserk data, usually with -40 CLT and -40 MAT, and to get it to read right i have to start the PID list and Dash page all over again from fresh.....
Yesterday I kept getting an error report with $31 code, which I looked up and then selected Shift f2 and it fixed it, and it worked fine.... until I added more PIDs, so I selected Shift f2 again, and noticed it actually removes all the selected PIDs from the PID list, so now I have a situation where I cant unselect PIDs in any of my PID lists, as they have all disappeared including my LS1 lists...
Am I missing something???

[Taz]

Attached is the modified E38 tune that you posted, with the Speedometer portion adjusted for your gear ratio and tire size. It should be close (usually within 5% of GPS speed). Use the Speedo Calculator to fine tune the speed - by adjusting the Tire diameter or Tire circumference as necessary.

I am using a newer version of the software (looks like you are using version 281), so you probably won't be able to open the tune that I posted. I also posted a PDF "how to" - so that you could do this for yourself.

EDIT: I forgot to mention that you should no longer need to use any type of Speedometer adapter / correction device.

[Hooter]

Thanks very much for that Taz, but although displayed vss on the scantool was close, the actual speedo was less than half the speed, similar to how I first began.
Yes I did have the earlier version, so i risked an update, which thankfully all went well....
The trouble Im having now is that I cant log any T43 PID's whatsoever as all are marked invalid.
Ive posted this elsewhere here, and here is another screen shot... whats going on??1921819219

[Taz]

Sorry that tune didn’t work out … not really sure what is causing this issue … below are two more tunes to try. Be very cautious using the “Test 2” tune, as it could act unpredictably.

The goal of all of this is to avoid the use (and cost) of any type of Speedometer correction device in future conversions.

Please log SAE.VSS and E38.VSS_DMA (if it is available), and compare to GPS speed.

I have not reprogrammed a V2 in quite awhile. I recall having issues once with the Options.txt being empty - and this causing problems.

[Hooter]

Thanks Taz, I tried your cals, but they resorted back to near correct ecm scantool speed reading, but actual speedo was less than half.
With my H0105 set at 202, my actual speedo reads correct without a speedo corrector, but my e38 scantool speedo reads approx 100 kms faster.
This isnt an issue so long as you have speed limiters set to max
My T43 santool shows/showed transmission speed as being near correct also, so I am happy with the way i have it
It would be good to have my e38 scantool reading correct, but it doesnt appear to be a big deal
I have used the Excel shift point correction spreadsheets i found on here, where you copy and paste your shiftpoint tables in, and along with setting tyre circumference and diff gear ratio with Rev limit. You need to do this when you have changed diff ratio and or tyre size, as the recalculate speedo and shiftpoints aren't available with E38/T43 software (yet).
The spreadsheet calculates along with each individual gear shift, the max speed (WOT) for each gear. For others reading this, its a very handy tool, as you enter these max speeds into the charts and then reshape both the normal upshift and downshift speeds to suit, and then copy and paste them back into EFI Live
You also set your WOT shift points to these.
I only wish I could get my Scantool to work, as all of my T43 PIDs have become unvalid, and some of my e38 and LS1 PIDs have as well, and Ive tried everything.
Maybe my V2 has a problem.... although it flashes and retrieves fine.
Anyone else experienced this??

[Hooter]

Something I forgot to mention is, on our earlier VE Commodore models, up to approx 2013, there is no VSS output from pin 16 in the A6 transmission plug to pin X1-71 in the ecm plug, and I have seen many instances where in conversions where, with no Body Control Module and no ABS, that you actually dont get any speed reading in your Scantool.
Whereas my 2014 VF does have this wired between the 6L80 and the E38...
Do any of you know if the American models have this????
Also our early Australian say VZ 2005 E38/T56 has an actual VSS (same as LS1), but the next model didn't have a VSS and the ecm got its signal from the ABS via canbus.
Is this the same for USA???

[Tre-Cool]

So i got my vy ute running with the 6l80e and looks like i got the same problem. however i can change the ppl value in the dash from the stock 6200 to 3000 and it bumps it up the speed closer to ecu speed.

I'm just going to try something in the tune to see if i can get it closer.

[Hooter]

So i got my vy ute running with the 6l80e and looks like i got the same problem. however i can change the ppl value in the dash from the stock 6200 to 3000 and it bumps it up the speed closer to ecu speed.

I'm just going to try something in the tune to see if i can get it closer.

From memory changing HO 0150 to 203 started things on the right path for me
Its all spot on now
Let me know how you go and I can send tune

[Tre-Cool]

From memory changing HO 0150 to 203 started things on the right path for me
Its all spot on now
Let me know how you go and I can send tune

Yeah i read that, but it screwed with your ecu vss didnt it? i guess at the end of the day as long as the tcm vss reads correct. shouldnt make a diff to what the ecu see's.

[Tre-Cool]

So i changed H0105 to 182
H0122 to 8
Modified the PPK value in my dash cluster to 3000 as that is the lowest it will let me input. If i could change it to 2600 i'd be much easier.

Now the TCM reports 100kph. ECU - 120~122 ish.
Dash Cluster matches TCM speed

That's with a 3.73 diff gear, I'll be changing to a 3.08 after the new year.