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I have a 2002 VY SS ute (auto). and my cluster has a wrong tacho reading. It appears to show less rpms than what it actually is. It was always like this

I have tried-
"resetting" the cluster, via eeprom, then matching it to my cars specifications
plugging in a friends cluster. it also reads low
putting a default tune on it, incase it had been messed with (which was true) but no difference to tacho reading
i have tried using an obd2 cable to read the engine rpms which confirms the issue, eg reads 650idle when cluster shows 300-400

mechanically i don't believe there are any issues with my car.

Is there any idea what it could be? i only appear to have an issue with the tacho reading, nothing else

any help would be appreciated

some1 has probably adjusted the tacho pulse settings in the ecu tune.

u might need to get someone to adjust it. it should have 6 pulses for low/high.

Thanks, I had a look at the tune im using. I'm using a "default" vats removed, hsv one, as I already assumed the ecu tune was the issue

I have a tacho low pulse of 6. and a high pulse of 6 also. The references on the tunerpro files I have, state :
v8 should be at 3 for both
v6 should be at 4 for both
v4 should be at 6 for both
which i'm a bit confused about. is mine correct already or should I adjust it?

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* EDIT, For those interested, I did find some information about the pulses
"ls1 pcm files are set for 6 pulses from factory"
So my pulses on my old and new tune are where they "should" be, at 6 pulses

So that's not the "issue". changing the pulses may help. If I find any info or can solve it I will post.

Well, why not simply try "v8 should be at 3 for both" and see how that goes ...

Joe.

I did some testing on the tune (tacho pulses) and found:

(In park)
6 pulse (default)
low cluster reading

5(not tested)

4 pulse
Close, reads 100 or so too low

3 pulse
Cluster reads too high

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4 pulse seems to be somewhat accurate, off by 100 or so
what the actual issue is i'm not too sure but I do seem to have found a "solution" from what I can tell.

I was going to say slightly lower than 4 might be perfect but its been brought to my attention it needs to be an integer

Bummer. Maybe your tacho is faulty?

Joe.

Thought so too, but I tried a mates cluster in mine and it still read low

because I still havent solved it and I came across something, can anyone answer this

I read my car in HpTuners and it says
Hardware: P01 ECM, GM Gen3 V8, 4.3L V6

what the hell is 4.3L V6? is this because ive changed the pulses, or the custom os? surely not, is it the pim?

moistlemons wrote:...because I still havent solved it and I came across something, can anyone answer this I read my car in HpTuners and it says
Hardware: P01 ECM, GM Gen3 V8, 4.3L V6...

From what I've read the same OS and computer (P01/ '0411) was used on (Vortec 4.3L) V6 and V8.
That part looks to be normal.

"4.3L V6" is normal. The HPT vin decoder doesn't properly support aussie vin decode. Its got nothing to do with the settings in the tune and can be ignored.