Author Topic: Dont start after jump start  (Read 8271 times)

Offline R-242tic

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Dont start after jump start
« on: May 19, 2015, 05:31:00 pm »
Have problem to start my car after dead battery, and I try to jump start it. I dont Connect wrong cables on the battery.   No lcd, no fuelpump.    Wiring, fuses, relay are okay. 
Something wrong inside the ecu?

Offline VEMS

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Re: Dont start after jump start
« Reply #1 on: May 19, 2015, 08:25:43 pm »
Hello R-242-tic,

Did you jump start using an unregulated booster or charger connected during cranking ? Than yes most likely the over voltage protection inside the ecu tripped.

Best regards, Dave

Offline R-242tic

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Re: Dont start after jump start
« Reply #2 on: May 20, 2015, 07:37:19 am »
I use a charger with boost function under cranking.  I have measure the voltage on the charger later, And it charge with 19-20 voltage, not good! 
Is there something I can do inside the ECU, or need it service on vems.hu? 

Offline VEMS

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Re: Dont start after jump start
« Reply #3 on: May 20, 2015, 09:24:44 am »
Hello R-242-tic,

I use a charger with boost function under cranking.  I have measure the voltage on the charger later, And it charge with 19-20 voltage, not good! 
Is there something I can do inside the ECU, or need it service on vems.hu? 

The 18-20v (when charging) most likely much higher when using boost function during cranking will kill your ecu! During cranking disconnect the charger.

If you are lucky it should be just a matter of replacing the transient suppression diode inside the ecu, it can be cut off until you find a suitable replacement (same type).
I highlighted the diode in the yellow circle here: http://vems.hu/dave/v3_top_channels_and_pins_transsp.png

If you have an ecu without the polyfuse (yellow square and flat device) on the bottom side, it might have blown a small fuse wire on the bottom of the pcb check (and replace if needed) this also.
When all else fails use the retest repair option in webshop to request a repair (and full checkup): http://shop.vems.hu/catalog/repair-upgrade-p-103.html (take care currently quite long lead time)

Best regards, Dave



« Last Edit: May 20, 2015, 09:27:50 am by VEMS »

Offline R-242tic

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Re: Dont start after jump start
« Reply #4 on: May 21, 2015, 04:39:56 pm »
I found some burned wires on the mainboard.   I make new wires, but when i tryed the ecu,  ignition fuse just broke.   
Do i have to remove the diod first?   And whats the name of the diod, where can i buy it?




Best Regards

Offline VEMS

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Re: Dont start after jump start
« Reply #5 on: May 21, 2015, 04:59:29 pm »
Hello R-242tic,

If traces burned of the PCB then you were not lucky. Your only option is to send the ecu in for repair using the repair upgrade option i posted earlier.

Best regards, Dave
« Last Edit: May 21, 2015, 05:18:52 pm by VEMS »

Offline fphil

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Re: Dont start after jump start
« Reply #6 on: May 21, 2015, 05:26:31 pm »
btw what about a 12V regulator to filter those spikes to be sold by the webshop?

Offline VEMS

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Re: Dont start after jump start
« Reply #7 on: May 21, 2015, 05:53:00 pm »
btw what about a 12V regulator to filter those spikes to be sold by the webshop?
There is already onboard protection protecting against these spikes (transient suppression diode) together with automatic polyfuse (snubber R), not sure what went on with this ecu (it is undoubtedly quite old), but the over voltage protection seems to be missing judging from the bottom side picture.

Best regards, Dave

Offline R-242tic

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Re: Dont start after jump start
« Reply #8 on: June 10, 2015, 09:16:53 pm »
The ecu was delivered for repair,  two injection output, the tranzient voltage supressor and the mcp3208 went out in controller.
Due to burnt traces and the possibility of broken cpu, so they hardly recommend mainboard replace.

Thank you for all help