terminal 87 3 location

[semeoneor]

trying to solve the issue i have in the check engine light photo screenshot biggest issue oil level sensor says inactive have some other codes also

3156 tank vent valve activation short circuit to ground
3157 tank vent valve activation line disconnection
3330 terminal 87 3 no voltage
3446 bsd message oil condition sensor missing
348F characteristic map thermostat activation short circuit to ground
3490 characteristic map thermostat activation line disconnection

shadow code DME map thermostat activation 2EF7

these codes dont cause any issues with drivability , got new thermostat same issues

biggest issue is oil level sensor doesnt work so i dont know the oil level , shortly happened after a motiv reflex controller installer so ill be searching around the dc/md/va area for a installer who can check the wiring

[MightyMouseTech]

The oil level sensor and MAP thermostat are on the same LIN BUS. You have a com problem on that BUS. Probably have alternator issues too then.

[semeoneor]

Originally Posted by MightyMouseTech

The oil level sensor and MAP thermostat are on the same LIN BUS. You have a com problem on that BUS. Probably have alternator issues too then.

alternator is working fine and was recently replaced with bmw oem part last febuary of 2021

[MightyMouseTech]

Originally Posted by semeoneor

alternator is working fine and was recently replaced with bmw oem part last febuary of 2021

When the alternator looses comms on the BUS, it just charges at a steady voltage as a fail safe.

[semeoneor]

Originally Posted by MightyMouseTech

When the alternator looses comms on the BUS, it just charges at a steady voltage as a fail safe.

how would i diagnose that bus port? disconnect the ethanol / reflex controller ? check a fuse?

[MightyMouseTech]

Originally Posted by semeoneor

how would i diagnose that bus port? disconnect the ethanol / reflex controller ? check a fuse?

Use a scope and check the waveform.

[Edwine90man]

Hey man was this issue ever fixed? Having the same issues with my 335i e90 n55

[semeoneor]

Originally Posted by Edwine90man

Hey man was this issue ever fixed? Having the same issues with my 335i e90 n55

Yellow fuse top row glove box fuses

[dcegreen]

i believe i am having this problem also(2013 135is)did you happen to fix it?

[tpl.mallon]

Originally Posted by semeoneor

trying to solve the issue i have in the check engine light photo screenshot biggest issue oil level sensor says inactive have some other codes also

3156 tank vent valve activation short circuit to ground
3157 tank vent valve activation line disconnection
3330 terminal 87 3 no voltage
3446 bsd message oil condition sensor missing
348F characteristic map thermostat activation short circuit to ground
3490 characteristic map thermostat activation line disconnection

shadow code DME map thermostat activation 2EF7

these codes dont cause any issues with drivability , got new thermostat same issues

biggest issue is oil level sensor doesnt work so i dont know the oil level , shortly happened after a motiv reflex controller installer so ill be searching around the dc/md/va area for a installer who can check the wiring

That combo of codes points way more to a wiring/power issue than bad parts.

Terminal 87.3 no voltage + multiple “short circuit/disconnection” faults (vent valve, thermostat, BSD oil sensor) usually means those components are losing power or signal, not all failing at once.

Since it started right after the Motiv Reflex install, I’d check there first, likely a bad tap, loose pin at the DME, or blown fuse on that circuit.

Oil level sensor showing inactive (BSD missing) fits that too.