When brake is pressed, MAP is incorrect. Disconnecting brake switch fixes the issue

[ElDominio]

As title states, seems brake switch input is mucking MAP.

https://youtu.be/s4iHTNE2S2A

[rusefillc]

@ElDominio please provide logs with vehicle not running and tapping on the brake pedal, need to see how MAP sensor voltage changes

[ElDominio]

brakelog.zip

raw voltage changes from 1.8 to 2.1

[rusefillc]

@ElDominio weird

One board or many boards? One vehicle or multiple vehicles? Only hyundai or any other models?

[ElDominio]

Only H154, 2x of them. Unaware of rev but definitely on-board wideband

Have not tested vehicles with hellen PNP's with working brake switches

[rusefillc]

@ElDominio please use DMM

• MAP signal
• 5v MAP supply

[ElDominio]

a car with an unknown revision does NOT have this issue, no wires have been cut? definitely older rev

braketest.zip

CurrentTune.zip

log shows me braking and voltage NOT changing

[ElDominio]

can we check if anything about this circuit changed from revD to revC? This is starting to become more of a problem as more units go out

[rusefillc]

@ElDominio revD is a complete re-work of the board, everything has changed between those revisions

@ElDominio did you have a chance to use DMM on revD board?

[ElDominio]

@rusefillc do i need to be able to press brake pedal? I have a Genesis with revD, but brake wire has been cut. If we only need 5v and map signal, I can do that, but brake does not affect this car

[ElDominio]

Reports:
Brake off:
MAP signal - 0.1v
5v MAP supply - 4.9v

Brake on
MAP signal - 5.3v
5v MAP supply - 4.9v

disconnecting brake input from ECU fixes the issue

[rusefillc]

@Qwerty-OFF ^^^

[rusefillc]

https://docs.google.com/spreadsheets/d/14IxjitlEFrC2bSp0IRdNRyXZondlvw2CmJ3Q9DUdvyo/edit?gid=0#gid=0

@Qwerty-OFF https://github.com/rusefi/rusefi_documentation/tree/master/OEM-Docs/Hyundai "2010 2.0 coupe" and "2014 * 2.0 coupe"

Looks like I've poorly articulated request and @ElDominio has responded vaguely. @Qwerty-OFF need your help articulating request much better than me.

[Qwerty-OFF]

@ElDominio please measure the following values with a multimeter:

	No Brake	Brake
GND - GNDA
GND - 5V
GND - MAP

[rusefillc]

https://rusefi.com/docs/pinouts/hellen/hellen154hyundai_revD/?pin=K14 agnd
https://rusefi.com/docs/pinouts/hellen/hellen154hyundai_revD/?pin=K31 MAP
https://rusefi.com/docs/pinouts/hellen/hellen154hyundai_revD/?pin=K30 5v

[rusefillc]

@Qwerty-OFF @ElDominio I am able to reproduce this on a bench - note 0.3v diff in voltage

https://rusefi.com/docs/pinouts/hellen/hellen154hyundai_revD/?pin=A29 floating

https://rusefi.com/docs/pinouts/hellen/hellen154hyundai_revD/?pin=A29 goes to +12v

[rusefillc]

@Qwerty-OFF

	No Brake	Brake
GND - GNDA	0	0
GND - 5V	4.9	4.9
GND - MAP	4.2	4.1-4.2

but raw MAP reads different value

[Qwerty-OFF]

[rusefillc]

no brake: in 4.2, out 4.2

@Qwerty-OFF

with brake: in 4.6, out 4.6

[rusefillc]

rev D/E brake and MAP share srv05

older rev B is not affected
https://github.com/rusefi/hellen154hyundai/tree/rev-b

"SRV05-4-P-T7","D200, D201, D202, D203, D204, D205, D102","SOT23-6","C85364"

[rusefillc]

rev E bad PN

https://jlcpcb.com/partdetail/Msksemi-SRV05_4_PT7/C6454456

[rusefillc]

rev B zero voltage leakage

best look

[rusefillc]

@Qwerty-OFF please provide perfect digikey/mouser PN

[rusefillc]

problem: there is another variation of S5 which while better than V05 is not perfect

[Qwerty-OFF]

https://www.mouser.com/ProductDetail/Semtech/SRV05-4.TCT?qs=rBWM4%252BvDhIe0tfPjqKjR5Q%3D%3D

[rusefillc]

@Qwerty-OFF а можно картинку, где мне искать 5в на мегамодуле, они же другие?

[Qwerty-OFF]