Voltage & Other Codes

[fastgoat]

I recently purchased a 2011 135i (6M). The previous owner installed an airlift system and JB4. Prior to purchasing, the car was throwing some codes but I took the dive as this is intended to be a weekend/project car. Running the codes on Bimmerlink show the following:

3330 Terminal 87_3: no voltage
3490 map thermostat, control: line interruption
3157 Tank bleeder valve control, line interruption
3446 BSD, communication (oil condition sensor): missing
2C90 Diverter valve: stuck closed

My understanding is these codes could be thrown because there’s no voltage to the terminal. I’ve checked the fuses, battery cables, engine ground cable, and DME fuses without issue. I’ve also had the battery on a trickle charger as Bimmerlink showed it was at 39% life. Even fully charged it’s still throwing the same codes. I’m now lost and was hoping someone had some insights before it goes to a shop. Car is still driveable.

[Slw1e82]

I would look into how the airlift or jb4 is wired. Electrical issues are tricky on these cars. If you have insta+ software that would be a great way to check wires correctly it will pin point where and what exactly to look for

[fastgoat]

I believe I was able to solve this issue. After reviewing all key fuses, nothing appeared to be blown. However, I did add a 20A fuse per the fuse diagram related to the CEL light and noticed a 20A in place of a needed 15A. Not sure which of these solved the issue, but the CELs have all cleared.

Note, before the fuses I did trace the JB4 wiring, Earth/ground wire in the engine bay, airlift wiring to the battery, and multiple visits to the fuse box...

[drwillb]

Where do you place the 20A fuse? I'm assuming it's for the JB4 system and the ever-present CEL for "tuner codes."