Yeah but it will have given you a lot more info than that, version numbers, speeds etc. - copy paste the whole lot? Or even just a screenshot
EDIT: Oh I see you've edited your post, never mind
I think you will be fine to just go for it and give it a try anyway though and see what happens - the VIN block is the same length and format, as is the ABD itself, so the worst that can happen would be an incorrect checksum and possible Check Engine Light. I think this is very unlikely though given that the same algorithm worked on the Mazda 3 and RX8 - why would the same gen 5 be any different?
Obviously I take no responsibility if anything goes wrong etc, blah blah blah usual disclaimer. Up to you whether you want to give it a try
JamieM wrote:Yeah but it will have given you a lot more info than that, version numbers, speeds etc. - copy paste the whole lot? Or even just a screenshot
EDIT: Oh I see you've edited your post, never mind
I think you will be fine to just go for it and give it a try anyway though and see what happens - the VIN block is the same length and format, as is the ABD itself, so the worst that can happen would be an incorrect checksum and possible Check Engine Light. I think this is very unlikely though given that the same algorithm worked on the Mazda 3 and RX8 - why would the same gen 5 be any different?
Obviously I take no responsibility if anything goes wrong etc, blah blah blah usual disclaimer. Up to you whether you want to give it a try
after the obvious disclaimer i gave it a try anyway...
but it does not work , I have already installed the steering wheel buttons, brake pedal switch and the missing wires to the ecu.
maybe I missed something or the elm adapter does something wrong with that error.
no check engine light , car drives normal
Nope your ELM definitely got the data onto the car (otherwise the program would have returned an error - it reads the data back at the end to check it actually changed on the car), can see it in the comms log. And no CEL means the checksum calculation works on your car too
Bummer. That's annoying. Maybe it's a different byte on the MX-5 or just doesn't work on that car? Or double check your wiring? Check the associated pin at the ECU changes resistance to ground when you press the various steering wheel buttons. Should be continuity for the main on/off button I think, and like 300, 600, 1200 ohms etc for the other buttons (unless the 5 is different to the 8).
I assume the NC1 has an electronic (drive by wire) throttle like the 8 yes?
JamieM wrote:Nope your ELM definitely got the data onto the car (otherwise the program would have returned an error - it reads the data back at the end to check it actually changed on the car), can see it in the comms log. And no CEL means the checksum calculation works on your car too
Bummer. That's annoying. Maybe it's a different byte on the MX-5 or just doesn't work on that car? Or double check your wiring? Check the associated pin at the ECU changes resistance to ground when you press the various steering wheel buttons. Should be continuity for the main on/off button I think, and like 300, 600, 1200 ohms etc for the other buttons (unless the 5 is different to the 8).
I assume the NC1 has an electronic (drive by wire) throttle like the 8 yes?
exactly , it is the same story as the rx8.
US cars had cruise on nc1 and on the EU it was locked.
on NC2 2009+ it was unlocked everywhere.
i will check everything again...
Thanks JamieM,
I was able to activate Cruise on my 2007 Mazda3 Diesel 1.6 on 2nd try, would have worked on first try, but the switch on the ELM327 needs to be on HS-CAN
Btw, I did it with the switches from a Mazda6 wheel, the whole wheel is much cheaper than the switches for M3
They just need a little rewiring to work.
Hi all - I have a 2009 Mazdaspeed Axela (Mazda 3 BL) which is equivalent to the 2010- US Mazdaspeed 3. There are differences in spec, notably that the Axela does not have cruise control fitted.
I have been attempting to activate this option on my vehicle.
I have obtained and fitted the cruise control buttons and verified the 4 pin brake switch. I contacted our local dealer to request that they toggle the cruise control option within the IDS, but unfortunately they were not able to locate an option to activate cruise in the menu options within the M-MDS.
I have analysed the as-built data from a number of similar vehicles and believe that the cruise control option may be located in the PCM3 data line. All cruise enabled Mazda 3 vehicles appear to have “PCM3 - FF41 F3FF FF44”, my vehicle has: “PCM3 - FF41 F1FF FF42”. This is a one bit difference in the third byte and an adjusted checksum. It seems to be the only bit in the as-built that relates to this difference in spec.
A couple of questions:
1. Can anyone confirm whether this byte in PCM3 is, in fact, the cruise control option?
2. Could the rx8cc software, or a variation of it, achieve this change?
I did test the AT commands on my ELM327 and it appears that the PCM data block may be at a different address than the RX-8/earlier model 3s. When I send the command 2100, I only get back a standard data block, not the extended one.
Managed to get a friendly dealer service manager to help reprogram the PCM with the changes. If you get access to the M-MDS, then there is a facility to manually load the as-built data.
Still not working however and its particularly hard to see what's going on as my cluster does not have a cruise LED. (Next step to install after its actually working). I have verified the cruise button voltages at the ECU and they are as expected.
I do also have a 4 pin brake switch, although checking PIDS, the BOO (Brake on) works as expected "on/off" with brake, but the BPA (Brake pressure applied) PID doesn't change from "Off". I will swap out the switch in case it is to do with adjustment.
A few more questions if anyone is reading this:
- Does anyone know where the BPA signal orginates? - the manual indicates is is Brake Switch Circuit No. 2, which I assume is the "continuity when off" part of the brake switch, but I'm not sure. I *think* the switch is working correctly based on testing out of the car.
- Would the lack of the LED in the cluster prevent cruise control engaging?
- Any other things to check? (neutral switch and clutch switch are all behaving as expected)
Are you absolutely certain you've flipped the correct bit in the as-built data? I don't know why it wouldn't work. The LED is just an indicator so shouldn't make any difference. Don't know what else to suggest.
RX8CC will not work if the VIN block is different / in a different location, all the checksums, offsets etc are based on that. You could use the same principal to write a very similar script if you can figure out the differences, but it sounds like it will be specific to your car, so not easy for me to do and with no way to test it I wouldn't feel comfortable doing it anyway (I'd effectively be guessing, the probability of screwing it up is too high).
It is strange that Mazda would change the data block / location on a very similar car though!
Yes, I agree - I wonder if it could be my interface. Not a problem, though, as I have the change made now on the PCM via the dealer.
As to whether its the right bit, I've double checked multiple VINs for PCM 1-9 and the bit I changed is literally the ONLY bit that differs between the models with and without cruise. In fact for the same model year, every PCM line is identical except that bit. I've also gone through all the 7XX-XX-XX parts of the as-built and PCM3 is the only bit that consistently differs for cruise. There don't seem to be any bits in the as-built that relate, so I'm pretty sure its right.
Good to hear your comment on the cruise light - I might have to rig up a temporary LED though, as its hard to see whether it is active, but not engaged or just not active.
If I get it working, I'll report back here in case its useful for any future versions you may release.
Is there any way to verify that the PCM3 line has in fact changed? - maybe the write failed on the M-MDS.
I tried directly entering the AT commands from the log down to the "2100", but as mentioned just got a brief response rather than the expected data block.
Would running the RX8cc.exe do any harm if it can't find the block in the correct location? - might be worth checking if it isn't likely to write anything.
