How to repair the DSC fault light suddenly lights up when BMW X3 is driving
Contributed by Netizens • 2 days ago • Auto Repair Notes • Read 1
The DSC fault light suddenly lights up when the BMW X3 is driving How to repair the DSC fault light suddenly lights up when the BMW X3 is driving Lights up the alarm. Failure Analysis: Connection I
How to overhaul a BMW X3 with a driving mileage of about 31,000 km and an F25 chassis: the DSC fault light suddenly lights up when the vehicle is driving. Troubleshooting: Connect ISID for diagnostics, diagnostic test trouble code memory column
A BMW X3 with a mileage of about 31,000 km and an F25 chassis
Fault phenomenon:
The DSC fault light suddenly illuminates when the vehicle is driving.
Failure Analysis:
Connect the ISID for diagnosis, the diagnostic test trouble code memory list is as follows:
480715 One wheel speed sensor: power supply, front right;
D51 A3 E-ICM interface (speed, 55.3.4): the signal is invalid;
D514BE; ICM interface(speed, 55.3.4): signal invalid;
E58500 Information (DSC Stabilizer, 0x173) missing, receiver EMF, transmitter DSC;
E58502 One information (vehicle height, 0XE4) is missing, receiver FRM, transmitter ICM;
E5850A one information (yaw rate, 0X19F) missing, receiver FRM, transmitter ICM;
E58509 Information (travel speed 0X1A1) missing, receiver FRM, transmitter ICM;
E0940E-Information (vehicle speed, 0X1A1) missing, receiver GWS, transmitter ICM;
D02C67-DSC interface (DSC stable system status, 47.1.2): the signal is invalid;
D02 C67-DSC interface (DSC stable system status, 47.1.2): the signal is invalid;
D017C5-DSC interface (actual wheel speed, 46.0.1): the signal is invalid;
DO 1 B03-EMF interface (hydraulic function request, 100.1.2): the signal is invalid;
D017A3 One-interface DSC (the actual number of tooth surfaces of the wheel sensor, 64.1.2): the signal is invalid;
D017BB one interface DSC (sum of actual braking torque, 43.3.4): the signal is invalid;
D015BC a message (DSC stabilization device status, 47.1.2) missing, receiver ICM, transmitter DSC;
D01782 - Information (HDC function data, 44.1.4) missing, receiver ICM, transmitter DSC;
D0179F a message (the actual number of tooth surfaces of the wheel sensor, 64.1.2) is missing, the receiver ICM, the transmitter DSC;
D017AB a message (wheel actual braking torque, 44.3.4) missing, receiver ICM, transmitter DSC;
D017Cl one information (wheel actual speed, 46.0.1) is missing, receiver ICM, transmitter DSC;
DO1 B3 A-message (Service Qualification ELBA, 63.1.4) missing, receiver ICM, transmitter DSC;
D017 B7 a message (actual braking torque sum, 43.3.4) missing, receiver ICM, transmitter DSC;
CD042-ZGM, FlexRay: Line fault on path 1.
Preliminary analysis of the fault content read from the ISID diagnosis may be that some important information of the DSC is lost. Execute the inspection plan, and the ISTA system analyzes the electrical fault. Identify the DSC control unit, which can be correctly identified by the DSC control unit. Continue to perform fault analysis according to the guidance of the test plan, the following fault data are stored for the tested function or component:
480715 One Wheel Speed Sensor: Powered, Front Right. Select the fault code and continue with the procedure. Check the following possible failure causes:
1. The wheel speed sensor is not installed/fixed correctly;
2. The detection head of the wheel speed sensor is damaged or contaminated;
3. The wire/plug connection of the wheel speed sensor is damaged;
Check that the right front wheel speed sensor is not properly installed/fixed, correct; the wheel speed sensor probe is not damaged or contaminated; the wheel speed sensor wire/plug connection is not damaged.
The fault content clearly refers to the right front wheel speed sensor, power supply. The sensor is directly powered by the DSC control unit to detect the power supply of the right front wheel speed sensor, and the detection result is 0V. It really is that the sensor power supply is abnormal, causing the lack of the right front wheel speed signal.
Next, disconnect the power supply line from the connection terminal of the DSC control unit to the right front wheel speed sensor, as shown in Figure 1. Measure the conduction between pins 1 and 2 of X34×1B to pins 34 and 33 of the DSC terminal, and the measurement result is an open circuit state.
Visual inspection of the DSC end wiring harness is OK, the right front wheel speed sensor wiring harness is connected to the wiring harness inside the right front fender inner lining. Removing the lower right front fender lining immediately found the point of failure. The wiring harness of the right front wheel speed sensor has been disconnected from the bus harness, and several wires on the bus harness are also torn, and the protective cover of the wiring harness is also missing. It is speculated that it was probably bitten by a mouse.
solution:
Connect and repair the wiring harness of the right front wheel speed sensor, delete the fault storage, the DSC fault warning light is off, and the fault is eliminated.
