E55: s/c magnet problem
I hope you can help me with the following issue. Last week, my mechanic placed a new 77mm s/c pulley and flashed the ecu with an updated RaceIQ tune. Also, he checked the pump, the vacuum hoses and the relais.
when test driving, the s/c did not spin. SDS mentioned a problem with the s/c magnet. However, when you put 12V on the magnet, it engages with a clunk. Can this be the problem with the diode in the connector of the magnet?
Any of you that can help me out?
thanks in advance!
KR Martijn




Easy things to check/do - unplug battery overnight to clear out ECU and adaptations etc. This will not erase your new map. Sometimes these cars see something new, or the connector was unplugged while the car had power and is now confused, so definitely try this first if you haven't already.
Does the connector and visible wires going to it look ok?
You asked about a diode, there is a resistor that is often sent with fixed pulleys that goes in that harness, but based on your post it appears you have a clutched pulley. If they sent a resistor, definitely don't use it. And maybe verify that Tony sent you a map for a clutched pulley (vs FSP).
Good luck!




also, the diode is fried. We are changing this diode and I will update you afterwards.
He changed the diode for a new one, and everything works as it should! The diode he used was a standard 12V diode, which prevents to run a current from the magnet back into the system.
Because the old diode was broken, the car was running in limp mode and the s/c was shut off.
I will give you an update about the invoice...
Have a nice weekend!


He changed the diode for a new one, and everything works as it should! The diode he used was a standard 12V diode, which prevents to run a current from the magnet back into the system.
Because the old diode was broken, the car was running in limp mode and the s/c was shut off.
I will give you an update about the invoice...
Have a nice weekend!


