Trying to figure out the problem that persists on DSC module of 325xi.
After changing brake master cylinder I got DSC trifecta fault codes - scan revealed Pressure Sensor Test Fault (Plausible Precharge Pump). I bled the system several times using pressure bleeder - the brake pedal is firm, no apparent air is in the system.
I can actuate the precharge pump - can hear it run and feel it pressing against the brake pedal.
The pressure sensor measures the hydraulic pressure once the car starts moving and achieves certain speed or engine torque, and precharge pump then charges the hydraulic system (briefly), I get DSC lights at that point, no lights are on when starting the engine.
My feeling was that there may be some air in the precharge pump itself and it does not achieve sufficient pressure for the DSC to read.
I took the car to the BMW where I was advised that DSC module is toast. I sent it out for rebuild and received it back. Upon installation the same fault persists, although the error code now is different - "Pressure Sensor Test Fault", no precharge pump plausability.
TIS reads pressure sensor data and shows hydraulic pressure from 0 bar to some 85 bar when pressing the brake pedal, so the sensor provides at least some data.
Could it be that pressure sensor failed (coincidentally) when recharging the hydraulic system?
I will try and bleed the system once again and see if I could run the precharge pump backwards to push any air back into the reservoir.
This problem is driving me nuts, I must say.
After changing brake master cylinder I got DSC trifecta fault codes - scan revealed Pressure Sensor Test Fault (Plausible Precharge Pump). I bled the system several times using pressure bleeder - the brake pedal is firm, no apparent air is in the system.
I can actuate the precharge pump - can hear it run and feel it pressing against the brake pedal.
The pressure sensor measures the hydraulic pressure once the car starts moving and achieves certain speed or engine torque, and precharge pump then charges the hydraulic system (briefly), I get DSC lights at that point, no lights are on when starting the engine.
My feeling was that there may be some air in the precharge pump itself and it does not achieve sufficient pressure for the DSC to read.
I took the car to the BMW where I was advised that DSC module is toast. I sent it out for rebuild and received it back. Upon installation the same fault persists, although the error code now is different - "Pressure Sensor Test Fault", no precharge pump plausability.
TIS reads pressure sensor data and shows hydraulic pressure from 0 bar to some 85 bar when pressing the brake pedal, so the sensor provides at least some data.
Could it be that pressure sensor failed (coincidentally) when recharging the hydraulic system?
I will try and bleed the system once again and see if I could run the precharge pump backwards to push any air back into the reservoir.
This problem is driving me nuts, I must say.
