[colman]

Hello,

Every few days or so I will get a group of codes when I accelerate to get on the highway, in 4th gear. If I accelerate quicker, these codes typically do not show up and they never have shown up on WOT pulls.

The half engine light is gone after restarting the car.

30FF (Have yet to diagnose where the leak is)
2E83 - Coolant pump power - reduced operation
2E85 - BSD: coolant pump: Missing
2E98 - BSD: Alternator: Missing
2E8B - BSD: IBS: Missing

Sometimes I get a Map-Thermostat code as well.

Bad IBS? Water pump going out?

This issue has been intermittently occurring before and after MHD stage 1 flash

Thanks for the help!


2009 335xi E92, BMS charge pipe, Tial BOV, BMS DCI, MHD stage 1

[dpaul]

You probably do not have a boost leak - 30FF is a result of the DME shutting off boost when the waterpump reports an error.

The BSD bus is a serial bus connecting water pump, alternator, oil level sensor, and the IBS (intelligent battery sensor) to the DME.

A fault in one BSD device can bring the whole bus down, resulting in communication errors with all the devices.

The fact that the fault is intermittent and only brought on under specific circumstances might be a useful clue but electrical problems can be difficult to troubleshoot. It could be a bad wire or/connector on one of the devices or the device itself. You could completely disconnect the oil sensor, IBS and even the alternator (the latter will stop the battery from charging) from the BSD bus without harm and see if the water pump error remains.

If I had to guess, it would be the water pump, given how often those things fail in the N54.

[colman]

Originally Posted by dpaul

You probably do not have a boost leak - 30FF is a result of the DME shutting off boost when the waterpump reports an error.

The BSD bus is a serial bus connecting water pump, alternator, oil level sensor, and the IBS (intelligent battery sensor) to the DME.

A fault in one BSD device can bring the whole bus down, resulting in communication errors with all the devices.

The fact that the fault is intermittent and only brought on under specific circumstances might be a useful clue but electrical problems can be difficult to troubleshoot. It could be a bad wire or/connector on one of the devices or the device itself. You could completely disconnect the oil sensor, IBS and even the alternator (the latter will stop the battery from charging) from the BSD bus without harm and see if the water pump error remains.

If I had to guess, it would be the water pump, given how often those things fail in the N54.

Ah good to know about the 30FF. This issue has occurred without the water pump codes before but always includes the alternator code. I suppose it is an electrical problem I need to investigate.

I'm aware of the water pump issue and have prepared for that inevitability.

Thank you for the information!

[southbaysteve]

Originally Posted by dpaul

You probably do not have a boost leak - 30FF is a result of the DME shutting off boost when the waterpump reports an error.

The BSD bus is a serial bus connecting water pump, alternator, oil level sensor, and the IBS (intelligent battery sensor) to the DME.

A fault in one BSD device can bring the whole bus down, resulting in communication errors with all the devices.

The fact that the fault is intermittent and only brought on under specific circumstances might be a useful clue but electrical problems can be difficult to troubleshoot. It could be a bad wire or/connector on one of the devices or the device itself. You could completely disconnect the oil sensor, IBS and even the alternator (the latter will stop the battery from charging) from the BSD bus without harm and see if the water pump error remains.


If I had to guess, it would be the water pump, given how often those things fail in the N54.

What he said ^^ Couldn't ask for a better response on what to look for. The
30FF is a part of engine control to protect an overheat/low pressure on coolant for the engine. I'm chasing my real 30FF (I popped it WOT so likely stock charge pipe or stock intercooler supply side broke).
Hope you get it fixed!

Steve

[colman]

Forgot to post the solution to my issue here.

These codes were due to a faulty voltage regulator on the alternator:

2E83 - Coolant pump power - reduced operation
2E85 - BSD: coolant pump: Missing
2E98 - BSD: Alternator: Missing
2E8B - BSD: IBS: Missing

The 30FF was due to wastegate rattle. I adjusted the rear wastegate by the threaded actuator rod, and the front wastegate with the washer method.

The thermostat code still comes on in the winter - it is failing in cold conditions and fails open so it takes forever for the car to warm up. This will be replaced with the waterpump soon.