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Top miles on a UB3 cluster


pitzel
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I did something similar when I advanced my Denali cluster from 29k miles to 120k miles. Instead of using a soundcard, I used a 555 timer chip generating square waves with a 50% duty cycle. The Denali cluster would advance at up to 2000mph, but once power was disconnected, it would reset back to original mileage since apparently it wasn't able to write to the EEPROM that fast. The fastest it would run and be able to permanently write to EEPROM was 800mph.

Just for kicks, I plugged my original cluster into the circuit and ran it as high as it would go, I think 999,999. At the point, it just stopped. It wouldn't roll over.

 

I'd be interested to know if the Cutlass cluster will actually roll over or not.

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Thats really cool, you certainly now your shit. Anyone figured out how to get 150kms to function? It shows up during post.

 

I think I'm gonna try and wipe the chip that stores that info and see if it still works after.

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Any way to set it BACKWARDS...?

 

The approach I am trying is to try and 'roll' it over the million mile mark, and then keep rolling it until I have set the appropriate mileage, in my instance, I am aiming for 111k km's.

 

My theory is as follows. 1636 miles/hour corresponds to 1820Hz for 1 hour.

 

1636 miles = 1820 * 60minutes * 60 seconds = 6552000 pulses.

 

So, roughly 4000 pulses per mile, each pulse representing a single internal counter tick.

 

Now, a million miles is 4000*1 million = 4 billion counter ticks.

 

4 billion counter ticks can be represented by a 32-bit counter, since 2^32 is approximately 4.096 billion. The math works out incredibly well for a million miles.

 

32-bit counters are relatively common electronic components, and I bet if I completely dissassembled the cluster, I would find one.

 

 

But a lot of the components are pretty hard to get at without a ton of soldering so I will try this approach first.

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If I remember correctly, all the IC's in the cluster are masked so there's no easy way to know which is the EEPROM.

 

I can pretty much identify most of whats visible on the rear side. Some of the part numbers are pretty much dead giveaways.

 

Are you referring to the stuff on the inside, where you essentially have to remove the display (by unsoldering the thousand pins that keep it in place)?

 

Some time hooked up to the probes of a logic analyzer (neat device we have that we use to characterize I/O of individual chips) would give a pretty good idea of the sort of data and the state transitions that are taking place. But praying that won't be necessary :P

 

Another way to approach the problem might be to electrically trace where those test pins go. i mean, you put a signal on the input of one of those and probe every pin on the board and see what, if anything lights up. The test pins should give a reasonable indication of where to send reprogramming signals (though that might be controlled in the i6530 that's sitting on there too). I personally suspect the 6530 is there to speak to and decode the ALDL bus though, and not to actually engage in transactions relating to the odometer.

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Thats really cool, you certainly now your shit. Anyone figured out how to get 150kms to function? It shows up during post.

 

I think I'm gonna try and wipe the chip that stores that info and see if it still works after.

 

I understand that certain functionality of the cluster, ie: the amount of redline that is present, and the 150 is controlled through ALDL. You would need therefore to modify the MEM-CAL in the main ECU in order to make it work.

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No, the chips behind the display I'm almost certain are just VFD drivers.

I can't ID anything other than the 4xxx CMOS logic chips.

 

I can't even find specs on the D457778 MCU nor the 6513 MCU which appears to be a Nippon Denso custom part (ND logo). Do you have any more info on those?

 

I think the NDM457 is the odometer chip, but that's just a guess based on what appears to be a deliberately placed access hole above it. That and it's also a Nippon Denso custom part. Not to mention I can actually pull up some digital odometer stuff on the web when I plug in NDM457, although that could just be coincidental. The test connector IS rather close to the NDM457, although I haven't traced the test pins to see if they go to the NDM457 or not.

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I can't even find specs on the D457778 MCU nor the 6513 MCU which appears to be a Nippon Denso custom part (ND logo). Do you have any more info on those?

 

Mine shows a 6530 and © Intel which makes it pretty obvious that it is an Intel 6530 microcontroller, fairly common out there. It probably has an embedded EPROM or OTP loadout to run the logic that it needs to run, hence the ND logo also on the chip.

 

Thanks for the info, next step, failing this I guess, will be to characterize that 457 chip. I guess the counter could be a serial device, who knows? Access hole, hmmmm.

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Mine is definitely 6513, but it does say ©Intel '80 so it's probably an older version of the same thing. I can't find anything on the web about it though.

If you can characterize the I/O of the 457 chip, you're way ahead of me!

I wouldn't even know where to start.

 

What is this 150kms thing?

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What is this 150kms thing?

 

Put your cluster into 'metric' mode and tell us whether it shows 150km as an option on the speedometer.

 

Just on the bench, mine doesn't. Nor does it show any redline either.

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The UB3 on regals have a small square dot that comes on just right of the odometer when you roll over 199,999 so you can tell it has 324,000 on it when the od is reading 124,000, I imagine cutlass's gp of the same vintage (88-95) do as well

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Thats really cool, you certainly now your shit. Anyone figured out how to get 150kms to function? It shows up during post.

 

I think I'm gonna try and wipe the chip that stores that info and see if it still works after.

 

I understand that certain functionality of the cluster, ie: the amount of redline that is present, and the 150 is controlled through ALDL. You would need therefore to modify the MEM-CAL in the main ECU in order to make it work.

 

On Canadian cars there is a pushbutton on the dash to switch between metric and imperial, kms,oil Pres in kilopascals,temp in celcius. There is also another mode switch which allows you to set the cluster to just display the hockey sticks, just the display digital mhp/rpm or both. The MemCAL chip is not different on Canadian cars tho, there are only 2 memcal chips for a given model, federal or california emmissions so you should be able to just wire in the switch someplace

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If you're cluster is on km/h when you first turn it on the 150km/h (which is also for 80mph) will light up during post.

 

The video of Daggar's UB3 shows it exactly, and his is a 3.4L so I doubt engine size matters.

http://www.w-body.com/forum/viewtopic.php?t=27162&postdays=0&postorder=asc&start=0

 

It sort of looks stupid cause it's not fully light like it is on mph.

 

I guess it just pisses me off cause there's no reason for it not to function other then GM's BS. :?

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The only reason engine size matters is for the redline.. It places it at 6k on the 2.8/3.1s, and at 7k on the 3.4s..

 

Actually the 3.4L redline is 6500 on the cutlass UB3.

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Redline info and tach signal come from the ALDL which gets the info from the ecm, so no they are not engine specific. I don't know if the info is the same on OBD1.5 as 1.0 so if you got a 3100 you might be SOL.

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