[ivannzowa]

Help me with W221 fault fix
I have Mercedes Benz w221,the ABS light is on,and the fault code is "power supply A7/3m1 high pressure and return pump

[autowerkes]

Help me with W221 fault fix
I have Mercedes Benz w221,the ABS light is on,and the fault code is "power supply A7/3m1 high pressure and return pump

have you checked all fuses in the front SAM unit? can you give more details about fault and what led to it?

[Wiseman]

Check SBC unit at front right

[Psxstar]

Check SBC unit at front right

If you want detailed information give please the vin
you should check the power supply on ABR traction Unit in Front.
Pin 1,2 and 32 is +12 volt and pin 16 and 47 is -(see my added wire diagramm)
you should check the supply with 5W lamp and no Multimeter advice.If the Both supplys are ok then the ABR Controll Unit or HydraulicTraction Unit is damaged.You should change the Control unit(ESP/ABR ECU) first with a other when the Error still Remains, then the Pump in Hydraulic traction is damaged so you need a hydraulic traction control unit.

Regards Psxstar

[euror]

Have the same problem and finally the complete hydraulic has to be replaced, only replace the ABR control unit does not help.