Crackers02 wrote:Cheers Martin. Were you able to workout the pinout for the bench testing? I know pin 10 and 14 is (Battery Positive Voltage) and 12 & 14 is ground; is it as simple as hooking up +12V and -12V to these pins?. I am ordering a GQ-4X Programmer this week to re-flash the main board EEPROM and HCE. Is it possible for someone to do a write up on basic use of these programmers for people who have not used these before?.
Hi
No I wasnt able to get my headunits powered up on the bench even following the GM wiring code on the plug, the units power up then lock out in security mode, awaiting msenj's response as she definitely had one that worked on the bench. Just to pickup on a trivial point, it is +12 volts and 0Volts (or GND) which gets connected to the HU (had visions of somebody with a -12 volt capable lab psu firing 24 volts through the HU and frying it).
Anyway, for programming, powering up the units is not required. I am not familiar with the GQ-4X but most programmer software works in roughly the same way:
first you clip onto the chip you are going to read (hoping you also bought a clip and cable to go with your programmer, they don't usually come with one)
with the programmer connected to the pc, you fire up the software and select the type of EEPROM you will be reading/writing
At this point SOME software will tell you which pins to connect the lead to on the programmer.
next you read the existing EEPROM data and save it as a file to backup the original content just in case something goes wrong
with the file still in memory, perform a verify to make sure you really captured the existing content without error
once verified, make a copy of the captured file with a different name then edit it with a hex editor
once the desired changes are made, save the file, open it in the programmer software and program the EEPROM
again verify against the modified file to make sure the chip was successfully programmed
Test the unit in the car (probably best if you don't screw it in until you verify it works).
Some footnotes to these generic instructions based on my experience doing this.
1. make sure you correctly orient pin 1 of the clip to pin 1 of the EEPROM there is the potential to fry the IC if you get it wrong
2. the programmer software is usually pretty flaky, dont be surprised if you get odd messages, badly spelled screens etc etc
3. because the software is flaky, it often reports correct dumps being obtained when in fact what you got was junk.......make sure you verify everything
4. the clips can be a pain in the butt to get seated properly on the chip, take your time to line it up well and often assisting the spring pressure a little helped with mine.
5. the SOIC chips sometimes have a laquered finish over the pins making the connections even less reliable, get a brand new paintbrush and cut the bristles down to around 5 mm and very carefully brush the pins outwards away from the chip to clean them up a little, again this worked well for me
6. read the docs supplied with the programmer, different chips will use different pins of the 40 way ZIF socket for programming (IE not all 8 pin IC's are programmed from the same 8 pins on the 40 way connector on the programmer). some software actually pops up a graphic when you select the chip type, telling you which pins to hook the EEPROM up to.
Out of interest, are you doing the full dual zone HVAC+LCD HU+Sensors conversion or are you doing the single zone+LCD HU with resistors conversion?
Hope this helps
I join others in wishing you and your partner well and hope all is OK. Sorry for late response, I've been busy on other things lately.
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