speedo and odometer calibration?

[flamed]

I bought my monaro about 3 yrs ago and it had 3.9 gears already fitted, at the time the speedo was reading correct, but the odometer was reading about 20% more. this wasnt a problem as the car was leased and the extra Ks helped. anyways I had a tune done on Saturday and the calibration in the ECU was still set at 3.07 which explains the ODO, but this was reset to suit the 3.9s and now the speedo is reading about 20% slow. I went to Holden today to see if they could reset just the speedo with Tech2 and apparently they cant. they suggested I go and get the speedo recalibrated through a gauge expert? what I would like to know is it possible that when the gears were fitted that someone recalibrated the Speedo only? and how/why would this be done & can it be reversed? any feedback or suggestions would be appreciated

[Sonnymad]

I bought my monaro about 3 yrs ago and it had 3.9 gears already fitted, at the time the speedo was reading correct, but the odometer was reading about 20% more. this wasnt a problem as the car was leased and the extra Ks helped. anyways I had a tune done on Saturday and the calibration in the ECU was still set at 3.07 which explains the ODO, but this was reset to suit the 3.9s and now the speedo is reading about 20% slow. I went to Holden today to see if they could reset just the speedo with Tech2 and apparently they cant. they suggested I go and get the speedo recalibrated through a gauge expert? what I would like to know is it possible that when the gears were fitted that someone recalibrated the Speedo only? and how/why would this be done & can it be reversed? any feedback or suggestions would be appreciated

Wat you have to do is go back to a dealer that has brains & they have to set the calibration in ur cluster bak to factory settings and this will bring everything bak to spec,if ur cars a auto,it will affect auto change points,if its a manuel,it really wont affect it,though its better to have it right,if you have any issues let me know and i,ll send you to a dealer to get ur cluster flashed bak to std.hope this helps.

:)

regards sonny

regards sonny

[planetdavo]

"Still being set at 3.07" suggests you have an auto..?
If that's the case, there is no "factory" PPK for 3.91 ratio auto's, only manuals, so the dealer would be correct and they cannot set it.
If it's a manual, refer Sonny's advice.

[flamed]

Yeah sorry guys it is an auto, If there is no PPK for the auto settings could a gauge specialist "easily" recalibrate it?
It was accurate prior to the Tune so why would it be working out of sync to the odometer which obviously it still is with out being adjusted?
Cheers Jeff

[VX2VESS]

nah he means set the dash back to 3.07 PPK at the dealer, so the new tune will read right on the dash. the dask ppk setting and the pcm diff setting are two very different things

he had the ppk changed for the right speed 3 years ago, now it been changed the right way with a tune in the pcm, however the old ppk change is still in the dash stuffing that up

most dealers can set the dask ppk back to the factory setting, except stupid ones..

if it had 17" rims originally its probably 6301 PPK

[Sonnymad]

nah he means set the dash back to 3.07 PPK at the dealer, so the new tune will read right on the dash. the dask ppk setting and the pcm diff setting are two very different things

Thats exactly right,if the dash has been messed with,iit "must" be restored bak to std,all diff ratios changes to speedo are done thru the "pcm"


regards sonny

[flamed]

Thats exactly right,if the dash has been messed with,iit "must" be restored bak to std,all diff ratios changes to speedo are done thru the "pcm"


regards sonny

Cheers Sonny
By having it reset will this affect the shift points? can you also let me know which dealer to go to. I went to one at Campbelltown today.
thanx Jeff

[Sonnymad]

[

Cheers Sonny
By having it reset will this affect the shift points? can you also let me know which dealer to go to. I went to one at Campbelltown today.
thanx Jeff


Jeff,

Gimme a call tom and i,ll organise it for you,it certianley will affect the shift points.

regards sonny

[VX2VESS]

or another way to think about it

the dash options can be programmed seperatlly to the pcm calibrations, The dash is just a smart display, it doesn't tell the pcm anything. one dash option is the conversion of pulse per minute (ppk) from the pcm. but no need as the pcm alone can do the conversion required for the right speed, if you do both you have two conversions going on.

sonny is right, ppk is bad news on autos, as a number of calculations and gear changes are based on the speed in the pcm. if dash ppk only is done the speedo/dash reads right, however the pcm and gearbox are 10 k's out or so depending on the ratio fitted. so pcm still does the wrong thing at the wrong time/speed.

adjust the pcm it makes everything right.


Jeff,

Gimme a call tom and i,ll organise it for you,it certianley will affect the shift points.

regards sonny

sorry incorrect sonny, i think you missed it was tuned last Saturday.

changing the ppk will not effect the shift points he just had done with some form of edit last week.

he had a new tune on saturday so they will be right, he has a wrong speedo reading due to the old ppk setting that was done ages ago, that his tuner didn't know about or din't update with a tech 2. he just needs the ppk back to the factory setting and the speedo will be correct. and his new tune will have done the rest already, if done properly. and reading now 20% wrong the other way now the pcm was done i'd say.

just get the ppk reset and you'll be fine.

if i'm wrong then i misunderstood the story in the first post. diff 3 yrs ago and only dash ppk done at that time i read...

[Sonnymad]

or another way to think about it




sorry incorrect sonny, i think you missed it was tuned last Saturday.

changing the ppk will not effect the shift points he just had done with some form of edit last week.

he had a new tune on saturday so they will be right, he has a wrong speedo reading due to the old ppk setting that was done ages ago, that his tuner didn't know about or din't update with a tech 2. he just needs the ppk back to the factory setting and the speedo will be correct. and his new tune will have done the rest already, if done properly. and reading now 20% wrong the other way now the pcm was done i'd say.

just get the ppk reset and you'll be fine.

if i'm wrong then i misunderstood the story in the first post. diff 3 yrs ago and only dash ppk done at that time i read...


Steve,

wat i am trying to say is,if the tuner adjusted his speedo to suit ,it would affect it,it wont affect it if the dash is wrong,it will just read wrong speed,hope this clears it up.

regards sonny

[flamed]

just get the ppk reset and you'll be fine.

if i'm wrong then i misunderstood the story in the first post. diff 3 yrs ago and only dash ppk done at that time i read... SPOT ON:yup:

Thanx guys the replies are great even I feel like I know whats going on now, Sonny I will be in touch later in the week to get a contact. great to know that people understand so much more then the so called experts and are willing to share.
Cheers Jeff

[MostlyBS]

I have the same problem in my VY SS.
I've installed 3.9's & at the time worked out the ppm & changed in the dash with a tech 2.

I now have a new tune & need to reset the dash back to stock.
Can anyone help with the stock ppm for a VY SS ute??
The original ratio was 3.46 I think

[DaveHAT]

I have the same problem in my VY SS.
I've installed 3.9's & at the time worked out the ppm & changed in the dash with a tech 2.

I now have a new tune & need to reset the dash back to stock.
Can anyone help with the stock ppm for a VY SS ute??
The original ratio was 3.46 I think

18" wheels - 6300
17" wheels - 6301

[MostlyBS]

Thanks for the fast reply.
I'll try it tomorrow

[smokey777]

im surprised at the VEs as mine is about 3-4ks (100 GPS = 103-4 speedo) out compared to GPS

[VX2VESS]

im surprised at the VEs as mine is about 3-4ks (100 GPS = 103-4 speedo) out compared to GPS

made that way on purpose speedos to always be over. manufactures don't want it the other way to get blamed for speeding with slight variation between cars they err that way so never reading less.

[Millsy]

i recently put 20s on my m6 vy ss with stock 3.46 gears and the speedo is now out by 5-6kph at 100 (checked against gps) is this a pcm thing, or can holden recalibrate the speedo? cheers

Millsy

[DaveHAT]

i recently put 20s on my m6 vy ss with stock 3.46 gears and the speedo is now out by 5-6kph at 100 (checked against gps) is this a pcm thing, or can holden recalibrate the speedo? cheers

Millsy

PCM ... get Chev to put it on the dyno and check the speedo against the indicated dyno speed.

Correction can be made through the PCM.

[smokey777]

made that way on purpose speedos to always be over. manufactures don't want it the other way to get blamed for speeding with slight variation between cars they err that way so never reading less.

ya i thought this & understand, it was funny as my VY SS before this was exact

[Millsy]

PCM ... get Chev to put it on the dyno and check the speedo against the indicated dyno speed.

Correction can be made through the PCM.

Dave its a HPF mafless tune, i heard that they are usually locked? :flipoff:

Cheers,

Millsy

[DaveHAT]

Dave its a HPF mafless tune, i heard that they are usually locked? :flipoff:

Cheers,

Millsy

Ah yes ... that old chestnut. :rolleyes:

Ask HPF to change it or ask Chev to see if he can read the tune ... then you'll have your answer.