[mcp]

No idea how this happened but I’m stuck in a culvers parking lot.

Just changed the oil, 7500 miles, i did change transfer case and diff fluids but shouldn’t be relevant.

Drove car to get gas, small lurch happened and CEL popped up, it was throttle potentiometer code which i’ve been getting so I sprayed the throttle body connector with cleaner and cleared the code and drove it to culver’s.

After I was done eating i get a long crank with no start. Throws a ton of codes.

2A9A Intake Camshaft Synchronization
3100 Boost Pressure Shutdown
2A80 Vanos Inlet Control
2A85 Vanos Outlet Control
2EF5 Thermostat Control
2E85 Water Pump Communication

All 6 codes come after clear + re crank. Water pump and thermostat are less than 10k miles old. Makes me think electrical issue. JB4 + MHD on the car but still no crank with JB4 disabled. Oil filter housing has the new o rings, aftermarket cap with metal cage so i didn’t forget it in the filter.

Vanos and cam sensor hasn’t been replaced AFAIK.

Next steps after I get it towed? Did my Vanos solenoids give out in a case of insane coincidence? Any help is appreciated.

[mcp]

Doing my own digging it seems like there’s 2 things that could be wrong, either something clogging the vanos track and the water pump codes are errant, or there’s an issue with the wiring/DME.

The water pump and thermostat codes indicate a BSD bus issue, but according to wiring diagrams, vanos + camshafts are on wholly separate lines. Unless the pins are right next to each other on the DME and shorting together i don’t see how something could hit all of these codes at once.

https://www.e90post.com/forums/showthread.php?t=1670915

This guy has nearly the same codes + later symptoms, leading me to believe it’s an issue with one of the connectors on the DME.

Car was purchased with JB4 pre installed. Wiring job for it looked very shoddy. Going to dig into the DME connectors on monday and if there’s nothing i’ll order the vanos solenoids; they probably should be replaced anyways.

Looking forward to what everybody else has to say.

[335i54n]

check the dme for water intrusion

[mcp]

Couple more issues. Car was towed home. When tried to start after work it is now a no crank no start. Radio says there is a transmission fault and AWD fault.

Watched the JB4 install video and the install in my car is similar but doesn’t match up. Pin used for the power replacement was extremely loose. Pushed it back in for now and tried to start it, to no crank.

Checked codes and there were none.

Pulled up ISTA and every single required to drive module is not responding anymore. Everything off of the JBE is red. DME, DSC, VTG, EGS, EKPS.

Battery voltage was low, but it’s been on a charger since saturday. Wipers are still doing the low battery constantly on, even though battery is fine now.

I’ll try digging into the wiring diagrams tomorrow after work, but man they’re confusing as shit. If anybody has any common fuses/relays/voltages to check that would be amazing.

[BRG_N54]

Depending on mileage and history I would look to the charging system, i.e. voltage regulator. Even if you charge the battery, a dead voltage regulator will cause all sort of codes and seemingly unrelated issues until it is corrected. New voltage regulator is about $50, and get the real Bosch one.

[924Carrera]

Originally Posted by mcp

No idea how this happened but I’m stuck in a culvers parking lot.

Just changed the oil, 7500 miles, i did change transfer case and diff fluids but shouldn’t be relevant.

Drove car to get gas, small lurch happened and CEL popped up, it was throttle potentiometer code which i’ve been getting so I sprayed the throttle body connector with cleaner and cleared the code and drove it to culver’s.

After I was done eating i get a long crank with no start. Throws a ton of codes.

2A9A Intake Camshaft Synchronization
3100 Boost Pressure Shutdown
2A80 Vanos Inlet Control
2A85 Vanos Outlet Control
2EF5 Thermostat Control
2E85 Water Pump Communication

All 6 codes come after clear + re crank. Water pump and thermostat are less than 10k miles old. Makes me think electrical issue. JB4 + MHD on the car but still no crank with JB4 disabled. Oil filter housing has the new o rings, aftermarket cap with metal cage so i didn’t forget it in the filter.

Vanos and cam sensor hasn’t been replaced AFAIK.

Next steps after I get it towed? Did my Vanos solenoids give out in a case of insane coincidence? Any help is appreciated.

I know this is a couple years old but I was hoping you might still be around and able to share what you were able to do to fix it, assuming you were. I have the exact same issue with my N54 535i, the same identical list of codes and behavior.

The first time it happened I was at the store; I couldn't clear all the codes with JB4, but I just disconnected the battery for like 30 seconds and then was able to clear the codes and it started right up without any problems.

The second time it happened I was fortunately at home. Disconnecting the battery did NOT resolve the issue. I ended up leaving it disconnected for about 45 minutes while I got into the E-box, pulled the K6300 relay, removed, cleaned and reinstalled the DME ground terminal, and unplugged and reconnected JB4 wiring. Finally I hooked the battery back up and cleared everything with ISTA and it started up just fine, but I'm worried this will keep happening more frequently. My only theory right now is that it's a warm start specific issue. But if you can share your fix, that would be awesome.

[BRG_N54]

Depending on mileage and history I would look to the charging system, i.e. voltage regulator. Even if you charge the battery, a dead voltage regulator will cause all sort of codes and seemingly unrelated issues until it is corrected. New voltage regulator is about $50, and get the real Bosch one.

Pull up the hidden KOMBI menu and monitor voltage before and after starting the car. Anything more or less than 13.5V-14.5V is an indication the voltage regulator is not working properly.

[GoRomeo]

Originally Posted by 924Carrera

I know this is a couple years old but I was hoping you might still be around and able to share what you were able to do to fix it, assuming you were. I have the exact same issue with my N54 535i, the same identical list of codes and behavior.

The first time it happened I was at the store; I couldn't clear all the codes with JB4, but I just disconnected the battery for like 30 seconds and then was able to clear the codes and it started right up without any problems.

The second time it happened I was fortunately at home. Disconnecting the battery did NOT resolve the issue. I ended up leaving it disconnected for about 45 minutes while I got into the E-box, pulled the K6300 relay, removed, cleaned and reinstalled the DME ground terminal, and unplugged and reconnected JB4 wiring. Finally I hooked the battery back up and cleared everything with ISTA and it started up just fine, but I'm worried this will keep happening more frequently. My only theory right now is that it's a warm start specific issue. But if you can share your fix, that would be awesome.

Double check your ground connections at engine bay. Look for lossen bolts holding the brown wiring. It happened to me after replacing my VCG in my E90. Tighten 1 bolt solved the issue.

[924Carrera]

This issue has happened again for the third time, stranding me at the store. I was able to get a ride home from someone to grab my laptop, come back and use ISTA to clear the codes; for whatever reason neither JB4 nor a generic OBD2 reader are able to clear them when this happens.

RE: previous thread suggestions, grounds are clean and secure, voltage is steady when running so regulator isn't looking like a culprit.

However, there is something very common that VANOS solenoids, cam sensors, thermostat and water pump have (the codes that come up every time) - shared power supply from Fuse F02 in the A8680 fuse block.

What else is common to Fuse F02? It's the one JB4 uses for its power supply.

That being said, I thoroughly examined, took apart, reconnected etc the JB4 power supply wiring and it looks perfectly fine and undamaged, so I'm not sure why it would intermittently (like once every 3 months) cause an interruption in this power supply circuit badly enough to trip the DME. I also removed and replaced fuse F02, but it looked perfectly intact.

For now my plan is just carry my laptop with ISTA and an inverter in the car at all times so I can clear the codes and get rolling again whenever this happens, but it would be nice to address the issue at the root. Short of deleting the JB4, which I do enjoy having, I'm not sure what else to do.

[mcp]

Originally Posted by 924Carrera

This issue has happened again for the third time, stranding me at the store. I was able to get a ride home from someone to grab my laptop, come back and use ISTA to clear the codes; for whatever reason neither JB4 nor a generic OBD2 reader are able to clear them when this happens.

RE: previous thread suggestions, grounds are clean and secure, voltage is steady when running so regulator isn't looking like a culprit.

However, there is something very common that VANOS solenoids, cam sensors, thermostat and water pump have (the codes that come up every time) - shared power supply from Fuse F02 in the A8680 fuse block.

What else is common to Fuse F02? It's the one JB4 uses for its power supply.

That being said, I thoroughly examined, took apart, reconnected etc the JB4 power supply wiring and it looks perfectly fine and undamaged, so I'm not sure why it would intermittently (like once every 3 months) cause an interruption in this power supply circuit badly enough to trip the DME. I also removed and replaced fuse F02, but it looked perfectly intact.

For now my plan is just carry my laptop with ISTA and an inverter in the car at all times so I can clear the codes and get rolling again whenever this happens, but it would be nice to address the issue at the root. Short of deleting the JB4, which I do enjoy having, I'm not sure what else to do.

Sorry, I don’t check forums super often anymore. I caused it when I was digging in the DME box to find the serial of the installed JB4. I rattled one of the piggyback wires wrong, and it took down the entire can network.

My diagnosis was just by re flashing stock tune (was on the piggyback helper tune), and removing the JB4. That fixed it. I did not diagnose which wire or connector had a bad connection.

I immediately purchased the full MHD maps and went on from there. Unfortunately I do believe mine was caused by the previous owner’s poor install as I didn’t really find any other note of bad wiring on JB4s, but it might be worthwhile for you to check.