Hello guys,
I hope someone can help me out.
I'm trying to flash a 95 ECM on the bench using EEHack, but i´m getting an error when doing the flash and i'm not sure what i'm doing wrong...
If someone can see the pictures and help me with this i would be very thankfull....
ECM: 16188051
Thanks
i did just answer this in a PM but just in case anyone else is reading:
VPP voltage if you aren't aware is a signalling voltage to the EEPROM in a state where it can be erased/reprogrammed. without VPP it's 'safe' to twiddle any pins without actually damaging information on the EEPROM, we need to supply voltage to that pin to do any damage to it.
unfortunately that flash routine built into eehack does not tell you why the VPP apply routine failed, it just gives up. my new flash tool will tell you but it's not quite ready yet.
if you are really curious why its failing, open eehack's debug log and check the 'verbose' box it will dump all of its bus messages. right after it fails it'll probably spit out a short message containing a return code, which i could use to tell you why its failing.
the VPP apply routine first checks the IGN voltage (it has to be 10.8 to 16 volts so that's unlikely to fail) but then it tries to apply VPP voltage and tests its output, which will fail if input voltage is insufficient. it must be in a very narrow range, so if your input voltage is too low, it'll fail. usually 11.5-13.5v of clean input is fine, though.
what is the ignition voltage in eehack if you just run a datalog for a few seconds?
be very careful flashing until you find out whats going on, a small failure might brick that ecm.....
Thanks for the quick answer...Originally Posted by steveo
I saw your PM now.
I will do some tests on the afternoon / night and see if i can get that Log messages and let you know...
Questions: from the USB-TTL adapter, do we need to connect the VCC to anything?
I just have the GND, RX and TX connected...
What is the purpose of that blue box between the pcm and power supply?
if your asking about the blue PCB were the cable go conneted, its and OBD2 adapter / PCB so that i can connect ECM/ECU, Dash, Immo box, etc for some bench tests...
In this case, i´m just using it to supply voltage and ground to the ECM, because it has several pinouts / connections that makes bench tests easier for me...
nope, just rx/tx and ground.
Ok, so i just tried again and still same error...
I'm uploading here the log you mention to do and also the picture of the "Stability Test" so that you can see that i got no errors...
Doing the flash, im using both "Skip Unused Regions" and "Insert Patches" options activated (not sure if this is the way).
As i remember i also read with those options activated...
Can you take a look at the log and see if there is anything i can do to solve this?
Also, about the voltage, when i tried this minutes ago it was giving me 13.6V.
I also made the test using 12V showing on EEHack and still same problem...
By the way, i tried to change VIN and it worked. I made the VIN change without any problems...
Can this be related to the COM por configurations? i have it setup with "1" in latency and speed with 9600 (Default)
Thanks
Last edited by boxsport; 04-03-2020 at 05:34 AM.
yeah the vpp voltage isn't sufficient, maybe its the power supply or a connection. check all your connections and power the ecm from a charged battery rather than your power supply to see if that works.
i just went up to 16v and still same error...
need to get a battery or a battery charger to test this.
I just realize that the USB-TTL adapter that i have has a Fake FTDI chip on it...() Can this be also the reason for this not to work?
Thanks
i don't think its a communication issue as it appears the command to set VPP is uploading and executing just fine, but after applying it, it's out of range. i would assume a noisy power supply or some kind of resistance. what is the battery voltage reported in the eehack datalog?
i might need to review all the wirings and probably make new cables because i´m using a protoboard and some "dupont" cables that like you say might create some noise...
the voltage i reported is the value that shows on the eehack "ECM voltage".
i will also try with another laptop i have just to make sure that its nothing to do with the laptop...
i will keep you posted
An electrolytic cap on the power of your breadboard should clean it up.
40v or higher, ~10-100uf should do it ;)
-Carl
thanks. i will try that. i should have some of those in some place here...
i'd say it would have to be a decent amount of noise to cause issues, the ecm does have some half-decent filtering of its own.
i developed eehack from start to finish with a crappy switching 1 amp wall wart (i think it used to power a cordless telephone or something). i wouldn't doubt if it had a single electrolytic cap with hot glue on it inside. for a lot of the time the wires were just twisted and taped together too. NEVER had an issue, and i reflashed that particular ECM many hundreds of times.
its usually when you put these things in cars with 20+ year old wiring that you have issues.. and it's not good wiring at all.. GM used the thinnest gauge possible.
another possibility is your ECM's VPP circuity is shot. this might be the first time it's ever been used. these are really old ECMs and were never intended for this length of service.
don't suppose you have an oscilloscope, do you?
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