Murdered530xi

2007 530xi N52B30

I was sitting in traffic the other day, not moving, when my dash lit up, 4x4 DSC limp mode activated.

I can still drive but because of limp mode it’s a hassle. If I pull over and pull the codes and erase them with my reader when I start back up the codes come back within 30 seconds.

If I erase all of the codes and then reset throttle adaptations I can get a clear slate and drive as normal but within 1/2 hr if I come to an idle stop…the tach will rise up 200 rpm then come back down and all of the codes will come back.

these are all of the codes:

ECM Codes

2D09 Throttle valve
2CED Throttle valve actuator jamming briefly
2CEC Throttle valve actuator jamming continuously
2F9A Ambient Temp Sensor

DTC Codes

55C3 AWD Limp Mode Activated
5F77 Engine Management Interface

My gut tells me it’s a throttle valve error/ communication throttle valve wire issue. I’m thinking the car goes into AWD limp mode because the ECM detects a problem with an erratic throttle valve (that 200 rpm) surge and then tells the DSC system to shut it down so the car can’t just decide to rocket ship itself wherever it pleases…hence all the codes.

my wallet on the other hand tells me that this may all be some kind of ECM wiring nightmare from the 6-7 times I’ve taken the air intake out dealing with starter issues.

everything on the car is stock. recently I replaced a the right side DISA valve, crankcase breather and hoses, intake gaskets (6) and the starter.

I welcome all of your thoughts.

Murdered530xi

Did find a similar post on another forum…
https://www.bimmerforums.com/forum/s...=throttle+body

habbyguy

The thread you posted was in reference to a 550i (a very different animal).

Thing is, your 530xi's throttle body really doesn't do anything under normal situations. The throttle body just lives its life wide open, and the "throttle" is the lift on the intake valves, the amount controlled by rotation of the Valvetronic system (the cam rotates and a small "lifter" sets the bias on the intake valve to change the amount of lift). Apparently this reduces (eliminates?) traditional intake manifold vacuum, making the engine much more efficient (and giving BMW dealers more maintenance and repair opportunities). I'm betting those codes have something to do with the throttle body NOT remaining wide open. I think the TB does close slightly under some conditions to help along the evaporative system though.

If you've had that intake off several times, you might have bunged something on the throttle body up a bit. I recently had mine out as well, and it's a really busy area down there where the TB lives - it would be dead easy to get something wrong.

There's also apparently a throttle body adaptation reset procedure, which sounds like a very good idea in this case (can't hurt, doesn't cost anything, and could save a whole lotta effort). ;-) It's probably easily found on INPA / ISTA or on one of the (many) BMW-specific code readers, but for those not so inclined, here's a process I found (but haven't tried myownself)...

1. Please make sure the ignition is Turned Off
2. Press the Gas Pedal to Full Throttle (while ignition is off).
3. Turn on the Ignition to the 3rd position for 30 seconds (Do Not Crank the Vehicle) (Do Not let go of the Throttle)
4. After 30 seconds are over, Turn Ignition Off and Remove Key (Do Not let go of the Throttle).
5. After Key is Removed, let go of the Throttle and wait 30 seconds.
6. After 30 Seconds, the Car can now be Started normally.

donpb

Throttle valve actuator could be dying or maybe something came loose. I remember when I was down in there, I kept thinking I had things connected properly but I did not.