DIY PSU Build for Flashing

[aboulfad]

Originally Posted by Jackog

...
Must have missed the seatbelt thing!

But can I ask, is it normal that it shuts down when connecting?
Thanks

No, it shouldn't shut down, how could it that be normal ? a PSU is supposed to provide a stable voltage, so if it shutdowns on connection there is something wrong with your mod.

Word to the wise, buy a finished product, sometimes its not worth the trouble to DIY. Most of us who did this had prior background with electronics. GL.

[psedog]

Double check the polarity. If that is correct then I think you have a bum power supply. Time to get another one.

[JakOG]

Hey guys,

Bit more info,

Firstly connecting the seat belt does not stop car from shutting down.
Timeout is 5 minutes.
Maybe because car is running 2015 istep/software?

I haven't been able to find anyone yet to build me a power supply, so in the interim I built another one.
I acquired another DPS600 and ran through the build carefully
Set it to 13.5 V output. Used 8ag cable.

Power supply will hold voltage when connected to car. Drops to 13.2V.
If I start the car with the power supply connected, it will shutdown.
I assume this is because if spikes the power supply.

As this is the second Power supply that does this, I can only assume it is normal behaviour.

Plan of action for tomorrow.
Run through Esys, get to the point just before flashing.
Connect power supply cold. Then power it on.
Flash car.
Try and do this in under 5 mins before car shuts down.

[aboulfad]

Jackog , it is very weird that your car is shutting down within 5mn to begin with, and then with driver seat belt fastened. This tip is from BMW's official ISTA-P release notes. My cars Istep was from March 2015 before I used the PSU for the first time and my car would shut down after 10mns if I didn't fasten driver seatbelt.

You can not risk your car shutting down during flash, in most cases Esys/car is robust to just abort the flash session, but in other cases it may be bad and you need to recover.

Regarding your PSU, it is not normal to shutdown even if you mod dozens of them! If the spikes shutdown your PSU, well that may happen during flash too! Did you try connecting the PSU to the car after ignition is ON. 13.2V with load is a tad low, aim for 13.5V.

[terahertz]

Originally Posted by Jackog

If I start the car with the power supply connected, it will shutdown.
I assume this is because if spikes the power supply.

You aren't really starting the car right? You're just turning on the ignition? Not starting the motor, correct?

If the motor is running, the alternator is probably outputting close to 14v, which would trip the over voltage protection on the PSU maybe.

You should not have the car running when flashing things. Only ignition on.

[aboulfad]

Originally Posted by terahertz

You aren't really starting the car right? You're just turning on the ignition? Not starting the motor, correct?

I am sure he meant turn the ignition on by "start" the car, that would defeat the purpose of a PSU

[psedog]

The drop down to 13.2 is a good one. That is most likely your current battery voltage. It will slowly increase as you are connected due to the battery charge level.
I'm assuming that when you said you started the car, that you cranked the engine. Once started the alternator would raise the voltage past your power supplies self protection levels which is why it's turning off.

As for the car turning off. If you started the engine and then turned it off. Your seatbelt won't matter. The car will be in an ACC mode which always turns off after 10 minutes (you can tell by your trip display being off and some of the iDrive features not being active). Next time just turn on the car (not start) then buckle the driver side belt.

Other methods that will kick your car into ACC would be to open the door while the belt isn't buckled.

One tip that I find a fool proof method is to plug in the OBD2 cable. String it to the passenger side. Put the key on the diver seat. Buckle the belt. Close the driver side door. Walk over to the passenger side. Get in. Plug the cable into your laptop (or wifi router). Press the start button.
This has always worked for me. It keeps me from worrying about if I open the door will it trip the ACC. I admit it's a bit overkill, but it works reliably for me. My other method is to roll down the window and route the cable out of the car and then pressing start (I'm standing outside of the car).

[JakOG]

Thanks Guys
Interesting info about the ACC on mode.
I'll try it out

I must admit I did actually crank the car in my early testing.
The problem I have, is that if I turn the car to ignition on without starting it, the fuel pump runs continuously. This happened after I accidentally coded DME with engine off a little while back. This fuel pump error is what I'm trying to fix with flashing.
If I briefly start the car, then turn it off, the fuel pump will stop running.

That aside, seems any little thing would trip the power supply.
I have since removed the potentiometer just for testing purposes.
Power supply is now rock solid. Can disconnect, reconnect, turn ignition on etc.
Still puts out voltage.

So I assume their is something wrong with the potentiometers on both supplies I have built.
I don't think the potentiometer is supposed to be that sensitive?
Maybe too much heat when soldering it?

I will buy a new one today and try it out.
I initially used the exact model of potentiometer shown in this thread
Wonder If I should try a different brand?

[JakOG]

Psedog

Spot on about the ACC mode.
Another mystery solved!

I pulled the fuel pump fuses, then turned ignition on, then plugged seat belt in.
Lasted past 10 mins!

So, I'm thinking I can flash this thing provided I pull the fuel pump fuses and have a working power supply.

Power supply works flawlessly until I connect the potentiometer.

Since a number of people have built these things successfully, I can only conclude its something I'm doing wrong. Maybe too much heat or soldering or bad soldering or too thin a gauge wire.
Regardless, I have now found someone locally who can build the power supply for me

[terahertz]

Originally Posted by Jackog

Psedog

Spot on about the ACC mode.
Another mystery solved!

I pulled the fuel pump fuses, then turned ignition on, then plugged seat belt in.
Lasted past 10 mins!

So, I'm thinking I can flash this thing provided I pull the fuel pump fuses and have a working power supply.

Power supply works flawlessly until I connect the potentiometer.

Since a number of people have built these things successfully, I can only conclude its something I'm doing wrong. Maybe too much heat or soldering or bad soldering or too thin a gauge wire.
Regardless, I have now found someone locally who can build the power supply for me

The pot is used to adjust the voltage. If the voltage is adjusted too high, it will trip the over voltage protection around 13.65v and it will shut off. That's my best guess as to what's happening since you say it works without the pot connected.

[JakOG]

I bought my 4ht Pentiometer yesterday and wired it up.
The other 3 pots must have been damaged by heat or spiking as they now don't work at all.
Works well but is a bit flaky when connected to car

I had it reading about 13.7, turned it down a little and seems to be behaving OK.
SO you may be right!

[dzvero]

Its weird you have to start the car. As terahertz stated it has something to do with voltage, not the potentiometer not working. GL

[JakOG]

I don't have to start the car.
That was something I had to do when their was a problem with the DME being corrupt and causing the fuel pump to run continuously whilst car was in ignition on mode.
I pulled the fuel pump fuses and was able to reprogram the DME, so I no longer have that issue.

I have 3 potentiometers that no longer work at all. turned up or down - whatever. They are dead.
My new one works just fine.

[terahertz]

Originally Posted by Jackog

I bought my 4ht Pentiometer yesterday and wired it up.
The other 3 pots must have been damaged by heat or spiking as they now don't work at all.
Works well but is a bit flaky when connected to car

I had it reading about 13.7, turned it down a little and seems to be behaving OK.
SO you may be right!

As I wrote in the DIY, there is the overvoltage protection feature of the PSU at 13.65v. That's probably what's going on. I have mine set at 13.5v with no load.

[FredDE]

This is pretty interesting, any chance to get the pictures back? I can´t see them

[terahertz]

Originally Posted by FredDE

This is pretty interesting, any chance to get the pictures back? I can´t see them

Dang. Sorry. I linked to the photos from the other forum. I don't actually have them anymore.

Maybe if someone goes through with making another they can take some? I actually have the parts to make one more, but don't have the time.

[aboulfad]

Similar photos can be found in the original forums that implemented this DIY. I think I?ve pasted the links in this thread somewhere. Also YouTube has few videos on the DIY.

[Pierre26]

Originally Posted by terahertz

Dang. Sorry. I linked to the photos from the other forum. I don't actually have them anymore.

Maybe if someone goes through with making another they can take some? I actually have the parts to make one more, but don't have the time.

+@Aboulfad !! (Thanks)

As i wanted to do this I recorded some of ones, see FA.
Still ''on the way'' because not much free time !
Anyway thanks for sharing the Bimmers real life

[terahertz]

Originally Posted by Pierre26

+@Aboulfad !! (Thanks)

As i wanted to do this I recorded some of ones, see FA.
Still ''on the way'' because not much free time !
Anyway thanks for sharing the Bimmers real life

Thanks! I attached it to the original post.

[Pierre26]

Ok, so first post still alive (like the cat )
Just received my Icom this afternoon, 48h from dhl Singapour (lightning sent ...)
And Now have to work ...

[jwzimm]

FYI to anyone looking to pick one of these up rather than build one. I have sold my M3 and I have the PSU that Terahertz build for me for sale here: http://f80.bimmerpost.com/forums/sho....php?t=1425270

I am open to offers too.

[Pierre26]

Originally Posted by jwzimm

FYI to anyone looking to pick one of these up rather than build one. I have sold my M3 and I have the PSU that Terahertz build for me for sale here: http://f80.bimmerpost.com/forums/sho....php?t=1425270

I am open to offers too.

I just bought two of ones for 4 Euros + shipping (20 E) ...
Going to connect them in // (13V-90A)
I saw on others threads that in this way NO need to isolate the negative DC part of the second unit.
They are each one linked with the Body unit AND the AC ground (verified with a multimeter).
About the moded Voltage on output, they told that they linked the 2 sensors (Pin7 and 9) with a calibrated resistance that works in // with the factory one inside used by the unit, I also put the correspondence:
1.8K ......... 13.8V
2.1K ......... 13.6V
2.3K ......... 13.5V
2.7K ......... 13.35V
3.3K ......... 13.2V
3.9K ......... 13.1V
4.7K ......... 13.0V
10K .......... 12.7V
I will verify after I received the Pins sockets, I took those from BMW, Réf = 1252 1 436 649 instead of unmounts the whole thing for what I want to have.
I think first try classic thread (Pin3 and 9)and both are running, before the new one and if the output doesn't look sufficient.
Aboulfad told about that he would try but didn't give the results.
https://www.rcgroups.com/forums/show...1#post22805472