Matt Cramer Posted June 22, 2007 Share Posted June 22, 2007 Hmm, how did you reload the firmware without the unit powering up? While it looked like it was not powering up, I ran a voltage check and established the voltages were normal, no sign of a short. However, because of firmware problems it was neither communicating nor blinking any LEDs. So it was actually powering up, but not showing any indication from the outside of being powered up. There are a lot of LEDs on the Megasquirt and the Stim, but there's no LED that just indicates the unit has power. Every last one of the LEDs only blinks in response to a processor output. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 22, 2007 Author Share Posted June 22, 2007 Is there is a way to "carry a spare" something just in case this happens again? Or is there anything that I could do to load the firmware should this happen again? I would hate to get stuck and know how to fix it but not have the proper tool with me. Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted June 22, 2007 Share Posted June 22, 2007 It's pretty straightforward to reflash it in the field. You'll just need a screwdriver to open up the case, and to equip your laptop with the appropriate programs. Then you can pop the top off the case, install the boot jumper by hand, and use the laptop to load the code. You'll find full instructions here: http://www.megamanual.com/ms2/code.htm Note that your Megasquirt has V2.687 code (I reloaded it with the same code it originally had to keep compatibility with your tune files) and the download files on that page have newer code which will not work with your MSQs. You can get a copy of the V2.687 code for reloading here, or update to the newer code and bring over your MSQ by hand. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 22, 2007 Author Share Posted June 22, 2007 I know I can reflash with the laptop but I was wondering if I could reflash if communications fail, like they did. Thanks for reloading the same code I was going to ask you to keep it the same. -Dave Quote Link to comment Share on other sites More sharing options...
naviathan Posted June 22, 2007 Share Posted June 22, 2007 You're not understanding, your comms didn't fail. Your code was corrupted so there was nothing to run the comms with megatune, however by setting the system in boot loader mode with the jumper it would take an upload of new code. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 22, 2007 Author Share Posted June 22, 2007 Ahhh OK. That makes sense. Thanks for clearing that up. The chip will take the new code once the jumper is moved....assuming it was still getting power, which it was. Kind of like flash updating the BIOS on a PC. As I get older...I get denser. Quote Link to comment Share on other sites More sharing options...
naviathan Posted June 22, 2007 Share Posted June 22, 2007 Ahhh OK. That makes sense. Thanks for clearing that up. The chip will take the new code once the jumper is moved....assuming it was still getting power, which it was. Kind of like flash updating the BIOS on a PC. As I get older...I get denser. Exactly, that's the best way to think of it is like flashing the BIOS on your computer. Quote Link to comment Share on other sites More sharing options...
Danno74Z Posted June 22, 2007 Share Posted June 22, 2007 Matt, Have you or someone else figured out why Dave's ECM had corrupted code or became corrupted over time? "Code corruption seems to be a common problem with the MS-II CPU...Wonder why that is...?" is this true statement or a very rare instance? Thanks, Dan Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 22, 2007 Author Share Posted June 22, 2007 In an email, Matt said that the code could become damaged by wires near the spark plug wires, or a bad configuration of Megatune. My laptop did lock up a few times while connected to MS-II while the car was running, but it ran fine after that. Also, when I just purchased the unit new, assembled, it would sometimes not boot up when I plugged the power supply into the wall. SO either: A) The code was flawed from day one. I "damaged" it when I made jumper mods for the 83 dist. and added the 4-bar sensor. C) My power supply (microsoft 120v AC - 12v DC wall wart) created dirty power that damaged the code. D) My laptop some how jolted the code during tuning. E) Spark plug wires too close to other wires. (not really a problem in my car AFAIK) My bet is either A) or C) Quote Link to comment Share on other sites More sharing options...
z-ya Posted June 22, 2007 Share Posted June 22, 2007 The embedded code should not just corrupt itself for no reason. Usually a hardware problem causes this. For example, if there were excessive noise on the boot pin (27) of the CPU, it could cause the CPU to enter bootloader mode. This may cause firmware corruption. They have a voltage divider setup off of the 12V, so when the boot jumper is not installed, that pin sits at 1/6 of 12V = 2.0V. When the jumper is installed, it essentially grounds the boot pin, put it into bootloader mode. I'm not sure why they pull the boot pin to a potentially noisy 12V, when they could have used 5V from the regulator, which will more stable, and cleaner. There really isn't any low frequency filtering on the 12V that the boot jumper is using. There is a MOV, which might help. Bottom line: adding a filter network to the 12V source for the MS could minimize this if in fact it is the cause. A car stereo noise filter might help. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 26, 2007 Author Share Posted June 26, 2007 I got the ECU back from DIY and it booted right up on the bench and I loaded in the msq and the sensor data and the Z runs fine again. I will look into a power stabilizer for the MS-II. What do you recommend? Specs? By the way I have a dedicated 10g wire from a new 800cca Optima Battery feeding the MS-II and all the EFI, FAN RELAY, COIL, FAST IDLE, DIST, MEGAVIEW, FUEL PUMP RELAY....I would think that the battery acts as a stabilizer. Main Power connects on the lower right terminal direct from the battery. Quote Link to comment Share on other sites More sharing options...
z-ya Posted June 26, 2007 Share Posted June 26, 2007 That 4GA wire will add inductance, but no measureable DC resistance! What you need is an LC filter (inductive and capacitive). This is what most of these car stereo filters have in them. They filter most of the low frequency (audible) noise on you cars 12V source. The MS has a 0.001uF capacitor inside, which will filter most high frequency noise that the MS could care about. You can build your own filter using this equation and calculator: http://circuitcalculator.com/lcfilter.htm You only need to filter the power going to the MS (not the coil, fans, injectors, etc.). So pick a filter with a max current rating of 10A. The MS probably draws around 1A by itself. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 26, 2007 Author Share Posted June 26, 2007 Thanks! Sounds like a plan. I will start working on the filter right away. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 4, 2007 Author Share Posted July 4, 2007 Update, I have not yet installed a 12v filter but now I carry the laptop equipped with the firmware ready-to-load just in case. I have had no more issues in about 300 miles of street tuning and cruising. It is running great. I think that the laptop must have killed the firmware because it's the only thing that I can remember being strange. It locked up once or twice while connected to MS-II and maybe it zapped it enough to make it unstable. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 27, 2008 Author Share Posted July 27, 2008 One year later.....I have not had anymore problems with the firmware going bad. I have installed a 12v line noise filter from a car stereo supply store. I have had problems with ignition dropping out and going haywire. I am going to post my ignition saga in a new thread. http://forums.hybridz.org/showpost.php?p=915851&postcount=10 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.