Hey how are you
What you need is A Star Mercedes diagnostic scanner to read the ABS module and retrieve fault codes and this way you can narrow down , is the module , abs sensor, yaw sensor ,low voltage ,charging issue etc...
2007 Mercedes Benz SL 550 (230.471) V8-5.5L (273.965)
GF42.45-P-4500-01SL Function of ESP control unit
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The ESP, SPS [PML] and BAS control unit (N47-5) is divided up functionally as follows:
^ Signal evaluation
^ Function logic component
^ Safety circuit
^ Additional functions
The following input signals are processed by the function logic component for calculations or as information:
^ Signals of left front rpm sensor (L6/1) and right front rpm sensor (L6/2), left rear rpm sensor (L6/3) and right rear rpm sensor (L6/4)
^ Steering angle sensor sensor (N49)
^ Rotational speed and lateral acceleration sensor signal
^ Stop lamp switch signal (S9/1)
^ Parking brake indicator switch signal (S12)
^ SBC pedal value sensor signal ((B37/1) model 230)
^ SBC pedal value sensor 1 (B37/1) and pedal value sensor 2 signal
SBC (B37/2) on model 240
^ ESP Off switch signal (N72s14)
Function logic component
The conditioned input signals are processed in the logic component and converted into output signals.
The following values and controlled variables are determined by the comparison of 4 wheel speed signals:
- Vehicle speed
- Wheel slip (normal brake application and ABS)
- Drive slip (ASR)
- Decel slip (MSR)
The change in direction of travel or cornering is detected via the steering angle sensor and different wheel speeds of the front wheels. These two detection variables in combination with the vehicle speed give the ESP, SPS [PML] and BAS control unit (N47-5) the driver's required characteristics.
The movements (rotational speed) which want to turn the vehicle about the vertical axis (B24/15) as they occur when a vehicle skids, are recorded in the ESP, SPS [PML] and BAS control unit (N47-5) by the rotational speed and lateral acceleration sensor. Using the signals from the rotational speed and lateral acceleration sensor (B24/15) the ESP, SPS [PML] and BAS control unit (N47-5) detects the effective driving characteristics of the vehicle.
Via the signal from the rotational speed and lateral acceleration sensor (B24/15) the ESP, SPS [PML] and BAS control unit (N47-5) determines the lateral forces when cornering. The drive status regulator in the ESP, SPS [PML] and BAS control unit (N47-5) detects an over steering vehicle from the lateral acceleration signal together with the rotational speed signal.
CAN data on engine torque
Via the CAN data bus the ESP, SPS [PML] and BAS control unit (N47-5) is informed by the ME-SFI [ME] control unit (N3/10) about the engine torque delivered.
CAN data on currently engaged gear (automatic transmission only)
The function logic section (ESP) is continuously informed by the EGS control unit (N15/3) about the current gear via the CAN data bus. The drive forces acting on the drive wheels are computed from this and used for drive torque control.
CAN information on brake pressures
Via the CAN data bus the ESP, SPS [PML] and BAS control unit (N47-5) is informed by the SBC control unit (A7/3n1) about the current brake pressures.
Parking brake indicator switch signal (S12)
If a signal from the parking brake indicator switch (S12) exists, then no engine braking regulation [MSR] closed-loop operation is permitted.
ESP Off switch signal (N72s14)
If a signal is applied from this switch, the drive torque control circuit is switched off and the ESP and ABS warning lamp (A1e41) is actuated permanently.
The safety circuit detects faulty signals from sensors, faults in the control unit and in the electric line system. If a fault is detected, then the system is switched off and this is displayed to the driver in the multifunction displays. In addition a fault code is stored in the control unit.
The safety circuit also constantly monitors the battery voltage. If the voltage drops below 10.5 V or rises above 17.5 V, the system is again shut down until the voltage returns to the specified range.
Indicator lamp actuation
The N47-5 signals for the ABS indicator lamp (A1e17), the ESP and ABS warning lamp (A1e41) are recorded by the ESP SPS [PML] and BAS and passed on to the instrument cluster via the CAN data line A1.
Partial function of speed-sensitive power steering
From the vehicle speed existing internally and the status signal the control unit computes the specified current for actuating the SPS [PML] solenoid valve (Y10).
Please let me know if that works for you or you need anything else on it
ASE Certified Technician