Trailblazer Mileage correction With Digiprog 3 Odometer Programmer

Theblackarrow

Original poster
Member
Feb 1, 2015
95
OK Hello Guys i made a small video for you all on how to Correct or Change the Mileage of Your Trailblazer Using Digiprog 3 odometer programmer
Before i begin i am confirming that this topic & video is only for educational purposes and not by any means to be wrongly or criminally used for cheating or manipulating with cars Mileage for Sales purposes Doing So is Considred a Fraud and is prohibited by law :popo: i have done this only because i had a problem with my mileage and i needed to correct it.

https://www.youtube.com/watch?v=61MznrvTdRw&feature=youtu.be



And here is some useful pictures for the same process
IMG_0816_zpsav9osrn4.jpg


IMG_0794_zpsy6gbniwf.jpg



IMG_0795_zpsbj9qwkn9.jpg


IMG_0815_zpsxwc73paw.jpg


IMG_0813_zpscts1fnna.jpg




IMG_0793_zpsiknaklrm.jpg









And here is the Final Result





Before

IMG_07321_zpsfktvhfui.jpg


After
IMG_0812_zpsgqrjxnd8.jpg


And here is some notes for doing this properly :-
  • For US Users Please make Sure to Check the Voltage of your adapter before connecting to AC (use the one included with the unit as it's 110-220 V ) Just to make sure you don't fry your programer
  • Also For US Users they Need to Change the Metric Unit from KM to MPG or Vise Versa From MPG to KM for European Users before reading or Writing on the Chip
  • You will need to Use The ST 01/2 Cable for the Trailblazer see Here
  • Very Very important to Connect the programer Clip as per the Pictures attached where the Red Color pin in the Clip is Up (See Picture No.6)
  • Before assembling the cluster back together connect it to the car first and check the mileage reading before installing needles back and installing the whole cluster back to the car
  • Also Very Very Very Important that you Always Save the Old chip data in the Programer for any thing goes wrong so you can write it back if needed or even if someone fried his chip and needed to install new chip it will be really easy to write it back
  • if you needed any time to restart again or your programmer got stuck while working simply take out the Power plug and reinsert it again to restart the programmer ( :nono: Never ever unplug AC power Plug when programmer is reading or Writing on the EEPROM CHIP otherwise you will destroy it :Banghead: :Banghead: )
In the End i hope you liked my Topic and i hope i did something useful to the GMTNATION and to the awesome members here ( Special thanks for MAY03LT my GM True Mentor :biggrin: )
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
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Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Great. Just great. Now I'm seriously thinking that my Saab's odometer was tampered with because it looks like it has more mileage than what it says. But this is still useful info for LEGAL and JUSTIFIED odometer manipulation, like after a cluster replacement. Good info.
 
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AtlWrk

Member
Dec 6, 2011
674
Awesome stuff! I just assumed the odometer data would be buried and locked away in the main processor's memory. Looks like a fairly basic, off the shelf, Atmel 2K eeprom (AT25020). Wonder if it's possible to read/write to the eeprom directly from a console or Arduino, etc. instead of their programmer :undecided: I do have a spare to play with...
 

Theblackarrow

Original poster
Member
Feb 1, 2015
95
Blckshdw said:
:goodpost: Looks like the cheapest I could find it was $163 shipped from here... That's only $40 more than it cost me to get my DIC cluster reprogrammed when I bought it a while back. I would have seriously considered buying this at this price point, help a couple local members out for a nominal fee, and it pays for itself! :yes:

New DIGIPROG III Digiprog 3 V4.88 obd version with OBD2 ST01 ST04 Cable Digiprog3 with Full Software multi-language
ya that's a great idea i thought also maybe some members can share it together and when someone needs it i believe it can be sent to him by post office and all USA members can get the benefit
 

Theblackarrow

Original poster
Member
Feb 1, 2015
95
AtlWrk said:
Awesome stuff! I just assumed the odometer data would be buried and locked away in the main processor's memory. Looks like a fairly basic, off the shelf, Atmel 2K eeprom (AT25020). Wonder if it's possible to read/write to the eeprom directly from a console or Arduino, etc. instead of their programmer :undecided: I do have a spare to play with...
Will that's a good point i believe unfortunately that the programmer only changes the Mileage in the cluster Not the One in the Car's computer system so i think any OBD2 programer reader will still read the actual one i will test that soon and update you :smile: But still i love to see my cluster with a low mileage :biggrin:
 

Theblackarrow

Original poster
Member
Feb 1, 2015
95
Blckshdw said:
:goodpost: Looks like the cheapest I could find it was $163 shipped from here... That's only $40 more than it cost me to get my DIC cluster reprogrammed when I bought it a while back. I would have seriously considered buying this at this price point, help a couple local members out for a nominal fee, and it pays for itself! :yes:

New DIGIPROG III Digiprog 3 V4.88 obd version with OBD2 ST01 ST04 Cable Digiprog3 with Full Software multi-language
Will i bought this one that has all the Cables for any Car which is a good investment for you guys to work with any car in the World :biggrin:

http://www.ebay.com/itm/Top-quality-Digiprog-III-Digiprog-3-V4-88-Odometer-Programmer-Digiprog3-Full-Set-/261795179216?hash=item3cf4356ad0&item=261795179216&vxp=mtr
 

AtlWrk

Member
Dec 6, 2011
674
What I meant was that I thought the mileage would have been stored within the cluster's processor, not on an auxiliary (and obviously accessible) EEPROM.

The cluster is the official repository of the vehicle's mileage, not the engine computer.
 
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Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
The PCM can be swapped without any issues except for a security relearn. Nothing is stored in there except the parameters for running the engine. The cluster is the only location that stores mileage.
 
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kickass audio

Member
Aug 25, 2012
955
Just out of curiosity for this. I am switching from a non-DIC to a DIC cluster. I have really good soldering/desoldering skills and was thinking of what if I unsolder the eeprom chip from my current non-dic unit and solder it into the new dic unit. Now I know they are two different setups so I don't know how that would behave but just an idea I had. Do you think that it would work that way or would the other parameters that make the DIC feature function not exist since the eeprom chip on my current cluster is for non-dic setups?
 

coolasice

Member
Oct 27, 2013
1,019
Northern Maine
AtlWrk said:
Awesome stuff! I just assumed the odometer data would be buried and locked away in the main processor's memory. Looks like a fairly basic, off the shelf, Atmel 2K eeprom (AT25020). Wonder if it's possible to read/write to the eeprom directly from a console or Arduino, etc. instead of their programmer :undecided: I do have a spare to play with...
it can be read/written to but you need to know what bytes to modify

kickass audio said:
Just out of curiosity for this. I am switching from a non-DIC to a DIC cluster. I have really good soldering/desoldering skills and was thinking of what if I unsolder the eeprom chip from my current non-dic unit and solder it into the new dic unit. Now I know they are two different setups so I don't know how that would behave but just an idea I had. Do you think that it would work that way or would the other parameters that make the DIC feature function not exist since the eeprom chip on my current cluster is for non-dic setups?
if you had a couple spares you could try it... or if you had a eeprom reader/writer you could clone one to the other or just dump both and compare.
 
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Theblackarrow

Original poster
Member
Feb 1, 2015
95
Robbabob said:
Did you confirm the original mileage was still read via an OBDII scan tool?
Well i checked the reading from the OBDII using the Same programer and it still reads 270000 KM so i don't know if it' an error as the programer can't communicate properly with the PCM so it's showing a false reading or it's the actual correct mileage i am really confused But still at least my Cluster is showing 150000 KM which is great still :biggrin:
IMG_0830_zpsgln20cuf.jpg
 
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Theblackarrow

Original poster
Member
Feb 1, 2015
95
kickass audio said:
Just out of curiosity for this. I am switching from a non-DIC to a DIC cluster. I have really good soldering/desoldering skills and was thinking of what if I unsolder the eeprom chip from my current non-dic unit and solder it into the new dic unit. Now I know they are two different setups so I don't know how that would behave but just an idea I had. Do you think that it would work that way or would the other parameters that make the DIC feature function not exist since the eeprom chip on my current cluster is for non-dic setups?
Well i believe it its impossible to do that the two cluster are totally different and i think you need to change more than an eeprom Chip see this post from LED Thread where you can see the difference clearly i do believe the only option you have is to replace a whole DIC Cluster with the Non DIC cluster you have and adjust the mileage.

Maybe some other more experienced members can answer your question with a more technical opinion :smile:

http://gmtnation.com/forums/topic/922-led-mod-thread/?p=420539
 
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kickass audio

Member
Aug 25, 2012
955
Theblackarrow said:
Well i believe it its impossible to do that the two cluster are totally different and i think you need to change more than an eeprom Chip see this post from LED Thread where you can see the difference clearly i do believe the only option you have is to replace a whole DIC Cluster with the Non DIC cluster you have and adjust the mileage.

Maybe some other more experienced members can answer your question with a more technical opinion :smile:

http://gmtnation.com/forums/topic/922-led-mod-thread/?p=420539
I was thinking the exact same thing and am just throwing out my idea to swap the eeprom chip and just send my cluster in to get it reprogrammed and be done with it. I will be testing the used cluster I bought on ebay tonight when I get home from work.
 

kickass audio

Member
Aug 25, 2012
955
I can tell you that it is not possible to simply swap the eeprom chip from the non-dic to the dic units. I didn't try to go back but after putting my non-dic eeprom chip in the dic cluster, it totally killed all the mileage in it. The odometer is at 0 and trip at 0. Luckily for me my new odometer has 183k miles and my truck now (before my dumbass screwed with the eeprom chip) has 138k miles on it. In all honesty, i don't care to get it reprogrammed. It is well past the high value in selling it for lower mileage as it has exceeded 100k and thats where I usually find the value diminishes a lot unless you kept up your vehicle but even thin it can get you in a loss. I learned several things to not do with the cluster. I learned to NEVER use a solder sucker to remove a bad stepper motor. My damn sucker ripped off the little pads on the circuit board at the rear where the wires come through. I luckily had some 22ga wire I used in m front doors to do the LED mod with so I used a knife to scrape the protective coating on the front side of the PCB where those 4 pins make contact at and ran the wires to the back of the board and soldered them on the little nubs that are on the stepper motor. I then put a dab of CA glue on the 4 corners of the front part of the PCB to secure the stepper motor in place.

I also found out that in another thread on here where people mentioned their battery light showing up very dim on the dash when the truck is shut off completely is actually an issue with the instrument cluster. As soon as I put my DIC cluster in, it didn't have the faint light of the battery LED on. Never bothered me anyway, I just dealt with it, but good things for others who may see that.
 
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kickass audio

Member
Aug 25, 2012
955
I found it way easier with the wick. I just add a bit of flux to it before and then a quick dab and its all gone. Live and learn. It's working fine now. I just need to see if my gas gauge is still spot on accurate. My new cluster has it so the needles don't go straight back to 0 for the temp, oil pressure and tach. but thats fine for me though.
 

AtlWrk

Member
Dec 6, 2011
674
So after a lot of false starts, Googling and relearning a bit of programming I was able to cobble together some Arduino code to dump the EEPROM from my spare cluster :biggrin: (yep a $20 Arduino, some jumpers and a SOIC-8 test clip was all it took :thumbsup:)

I also made dumps with 1 mile more on the odometer and 10 miles more so I can compare side by side to see what bytes have changed and how to decipher the data but I haven't gotten to that yet.

Odometer: 101880
Trip: 0

0x00 0F 8B FF FF FF FF FF FF FF FF FF B8 0F 8B FF FF
0x10 FF FF FF FF FF FF FF B8 0F 8B FF FF FF FF FF FF
0x20 FF FF FF B8 43 54 21 30 00 02 10 09 0F 00 00 00
0x30 0F 0F 0F 0F 00 00 00 59 72 73 00 00 08 54 61 C0
0x40 00 00 A5 00 42 40 3C 43 3F 44 51 3A 56 4E 4E 48
0x50 54 57 00 00 00 00 00 00 A5 00 00 00 00 00 00 00
0x60 00 00 00 00 31 47 4E 44 54 31 33 53 36 34 32 31
0x70 33 34 38 38 31 00 10 04 04 04 10 04 00 00 00 00
0x80 00 00 00 00 30 35 30 46 30 30 30 30 30 31 32 32
0x90 33 48 59 00 E6 5C 1D 44 50 58 55 00 00 00 00 00
0xA0 00 32 31 33 36 60 00 00 00 00 48 50 4A 18 C2 84
0xB0 D7 17 F9 A6 48 18 3A 5B 48 18 B8 90 E8 1B 80 A9
0xC0 03 00 00 65 04 00 A5 00 00 00 00 00 00 00 00 00
0xD0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0xE0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0xF0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Also, sorry OP :hijack:
 

AtlWrk

Member
Dec 6, 2011
674
The one I'm playing with is non-DIC, though I do have DIC I'm going to be swapping into my truck soon. I have the mileage on the DIC unit really close and when it comes time I'll match it up exactly using a signal generator on the vehicle speed input to the cluster. The odometer just counts pulses (4000/mile) on that line and increments accordingly. Obviously this only works if you need to count up and you're limited to about 230mph on the speed signal before the cluster freaks out. If you have a long way to go like I did it can take days letting it run for it to catch up. But now that I'm close I probably won't mess with the EEPROM on it (though getting a dump from it would be fine).

I haven't tried writing to the cluster EEPROM yet. There's no technical reason I can see why I shouldn't be able to, I just haven't gotten to that step yet.


B8 0F 8B FF appears three times in the first three lines (1 is split up) and changes as the odometer updates:

B8 0F 8B FF (101,880 miles)
BD 0F 8B FF (101,881 miles)
FF 0F 8C 14 (101,890 miles)


No other bytes changed. This is all in line with what I've come across Googling. The trick now is deciphering how that data corresponds to the odometer reading (order, bit inversions, other conversions, etc.)...could be tricky.
 

coolasice

Member
Oct 27, 2013
1,019
Northern Maine
Odometer: 101880
Trip: 0

Multiply odometer x 10 = 1018800
Convert to Hex =0F8BB0 (yours is 0F8BB8 as it has 101880.8 mi)
0x00 0F 8B FF FF FF FF FF FF FF FF FF B8 0F 8B FF FF
0x10 FF FF FF FF FF FF FF B8 0F 8B FF FF FF FF FF FF
0x20 FF FF FF B8 43 54 21 30 00 02 10 09 0F 00 00 00
0x30 0F 0F 0F 0F 00 00 00 59 72 73 00 00 08 54 61 C0
0x40 00 00 A5 00 42 40 3C 43 3F 44 51 3A 56 4E 4E 48
0x50 54 57 00 00 00 00 00 00 A5 00 00 00 00 00 00 00
0x60 00 00 00 00 31 47 4E 44 54 31 33 53 36 34 32 31
0x70 33 34 38 38 31 00 10 04 04 04 10 04 00 00 00 00
0x80 00 00 00 00 30 35 30 46 30 30 30 30 30 31 32 32
0x90 33 48 59 00 E6 5C 1D 44 50 58 55 00 00 00 00 00
0xA0 00 32 31 33 36 60 00 00 00 00 48 50 4A 18 C2 84
0xB0 D7 17 F9 A6 48 18 3A 5B 48 18 B8 90 E8 1B 80 A9
0xC0 03 00 00 65 04 00 A5 00 00 00 00 00 00 00 00 00
0xD0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0xE0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0xF0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Your VIN is also stored here


31474E4454313353363432313334383831 = 1GNDT13S642134881
 
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coolasice

Member
Oct 27, 2013
1,019
Northern Maine
AtlWrk said:
Holy crap! That is amazing :eek: :thumbsup: :thumbsup: :thumbsup: :thumbsup:

I really didn't think it would be that straightforward.
Figured that out with some trial and error with software called tachosoft. Would like to see the dic version, isn't there some welcome text when the dic version is started up?
 

AtlWrk

Member
Dec 6, 2011
674
Funny, the ToyotaNation forum that got me started on this road mentioned the TachoSoft software for decoding too.

I just see "Unknown Driver" when I power it up outside of the truck--not sure what normally comes up but I see what you're getting at :undecided:

Unfortunately I'm leaving on vacation straight after work so I won't be able to get the EEPROM dump from my DIC cluster until Sunday/Monday.
 

AtlWrk

Member
Dec 6, 2011
674
Here's the dump from my DIC cluster. Turns out the bytes in red are actually the odometer ones (with the 10x factor but no re-ordering). It must've been a coincidence that the other worked out. I was able to write those address locations with my mileage and showed up correctly when I powered up the cluster :thumbsup:

0x00 16 4E 5A FF FF FF 56 FF FF FF FF FF 16 4E 5A FF
0x10 FF FF 56 FF FF FF FF FF 16 4E 5A FF FF FF 56 FF
0x20 FF FF FF FF 43 56 11 94 00 00 28 81 0F 00 00 00
0x30 0F 0F 0F 0F 00 00 00 59 72 73 00 00 32 8B F3 6C
0x40 00 00 A5 00 43 4F 3C 3A 49 40 51 50 4F 4F 53 49
0x50 47 4E 00 00 00 00 00 00 A5 10 00 00 00 00 00 00
0x60 00 00 00 00 31 47 48 44 54 31 33 53 39 32 32 32
0x70 30 33 39 38 33 00 04 04 04 04 04 04 00 00 00 00
0x80 00 00 00 00 30 35 30 46 30 30 30 30 30 31 31 33
0x90 30 48 50 00 E6 2F B7 44 4E 4E 43 00 00 00 00 00
0xA0 00 31 31 39 35 19 00 00 00 00 88 3E DA 22 88 3E
0xB0 DA 22 19 28 2D 1A 00 00 00 00 00 00 00 00 80 A9
0xC0 03 00 00 65 04 00 A5 00 00 00 00 00 00 00 00 00
0xD0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0xE0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0xF0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 
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coolasice

Member
Oct 27, 2013
1,019
Northern Maine
That dic cluster is for a 2002 bravada... Maybe they had slightly different programming?
 

AtlWrk

Member
Dec 6, 2011
674
Hmm, something odd here. Looking at the original data:

using the method you described:

B8 0F 8B FF --> 8B0FB8 = 1018808 = 101,880.8 miles
BD 0F 8B FF --> 8B0FBD = 1018813 = 101,881.3 miles (perfect, trip showed 0.5 miles)

but then at 101,890:

FF 0F 8C 14 --> 0F8CFF = 1019135 = 101,913.5 (???)

however:
directly using 0F8C14 = 1018900 = 101,890.0 miles (correct)

Programming my mileage (146k+ miles) using your method I ended up a few miles off. Using the addresses highlighted in my last post showed up correctly on both the non-DIC and DIC clusters. I tried a variety of mileages all over the range on the DIC cluster and they came out as expected. I really can't explain what happened and why the memory locations jumped like that.

Anything else fun embedded in the eeprom you can see?
 

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