How To: 99-02 GM Truck

**garnerm** · 23rd March, 2019, 04:08 PM

This how to is a short one for 99-02 GM trucks. This covers Silverado, Sierra, Tahoe, Suburban and Yukon. This is for people like me using a MiniPro or gq-4x4. Note of caution I do not recommend trying to use a cheap manual desoldering pump to remove the smd board from the the cluster. The main board has really easy to lift solder pads. I have anesty zd-915 and it worked fine for me. This is the hard way to do it. The easy way is to drop the old board into the new cluster but if its going from non trans temp to to a trans temp cluster you can't just drop it in.

What you need: EEprom programmer like a Minipro with SOIC 8 adapter, Tachosoft (its free and on this website), a hot air station, soldering station, solder and flux.

First remove the the SMD board off the through hole board. It is 64 pins so this i would say is the hardest part I guess even though its still easy to do. I know with the carprog and some of the other flash tools you can solder on the the back of the board and do it in circuit but since we are using a minipro I would rather remove the EEprom to insure a good clean flash and reading.

Now that its off the main board get your hot air and flux out. Remove the EEprom pay attention to the correct orientation. Once that is free drop it in your programmer and read it, save a backup of the original Bin. I read/flash it with ST m95020 protocol I have seen other people use the ATMEL protocol but the ST works for me.

Since we now have a bin file on back up and a second copy to play with open up Tachosoft to get your mileage. First thing you will notice is the mileage isn't stored in plain text so you will need the software to convert it for you. Second thing you will notice if you are over here in the US the mileage is stored in K's so you need convert the miles you want into K's first then put it in the software. take you values from Tachosoft and edit your bin. Flash using the same protocol.

Simply reverse taking it a part and now you have changed the miles or K's depending on where you are at.

I figured for my 2nd Post I would do a short how to that is hopefully useful to someone. Last note the the numbers aren't perfect but you will be within 250 miles of what you wanted... better than 100,000 miles.

**rukartinatv** · 24th March, 2019, 02:25 AM

This car work thru obd
30 sec job

**clusters** · 24th March, 2019, 03:02 AM

Or through back solder points (which he also posted), nobody in their right mind removes the board to correct these.

**garnerm** · 26th March, 2019, 10:21 PM

Originally Posted by clusters

Or through back solder points (which he also posted), nobody in their right mind removes the board to correct these.

Well to be fair I am never in my right mind

.
True to both the above comments. I guess I was just trying to share another tool for your tool box if you just have cheap programmer laying around and need to do just do one. This is not the way to do it for someone doing this for a living. I Did myself just to see if i could do it and I've had my minipro laying around for years I used to flash EEproms for old GM TBI/TPI units. Im just cheap Hobbyist messing around with this stuff for fun. I didn't know these could be flashed in the OBD port.

**AppolageticSoul** · 27th March, 2019, 08:32 AM

use to in my young days till i found out about the back connections and then the joys of obd :>

**garnerm** · 5th April, 2019, 04:48 AM

Ok I got a question. I noticed that the trip resets it's self every time the cluster reboot s but only after it's been reflashed. What's up with that?