ABS warning. code: "the ABS sensor right front wheel". After replacement of ABS sensor the function was OK. After 100 m the ABS warning lamp turned on again. New code: "malfunction in the ABS sensor.

The code refers to the right front wheel speed sensor. The fact it is intermittent says that you have a bad connection or a fractured wire or a bad ground. Check out the videos

C0040 - OBD II Trouble Code: Right Front Wheel Speed ...

https://repairpal.com > obd-ii-code-c0040
C0040 18: Code C0040 18 indicates the ABS module has detected the right front wheel speed sensor signal amplitude is below minimum. More OBD-II Codes. C003E.

Video Help

The ABS system means the Antilock Brake System. If the ABS lights on the dashboard permanently the ABS system is faulty. You must access the ABS Electronic Control Unit (ECU) memory to pull out all DTC (Diagnostic Trouble Codes), using diagnostic equipment connected to the data link connector of the car. Then you will be full informed about bad pieces (e.g.: front right wheel abs sensor interrupted, ...). After bad pieces replacement you will be able to erase all faults memored by ABS ECU, in other words reset the ABS system and turn off the warning lamp on dashboard.

The ABS system means the Antilock Brake System. If the ABS lights on the dashboard permanently the ABS system is faulty. You must access the ABS Electronic Control Unit (ECU) memory to pull out all DTC (Diagnostic Trouble Codes), using diagnostic equipment connected to the data link connector of the car. Then you will be full informed about bad pieces (e.g.: front right wheel abs sensor interrupted, ...). After bad pieces replacement you will be able to erase all faults memored by ABS ECU, in other words reset the ABS system and turn off the warning lamp on dashboard.

The ABS system means the Anti-lock Brake System. If the ABS lights on the dashboard permanently the ABS system is faulty. You must access the ABS Electronic Control Unit (ECU) memory to pull out all DTC (Diagnostic Trouble Codes), using diagnostic equipment connected to the data link connector of the car. Then you will be full informed about bad pieces (e.g.: front right wheel abs sensor interrupted, ...). After bad pieces replacement you will be able to erase all faults memored by ABS ECU, in other words reset the ABS system and turn off the warning lamp on dashboard.

The ABS system means Anti-locking Brake System. If the ABS lights on the dashboard permanently the ABS system is faulty. You must access the ABS Electronic Control Unit (ECU) memory for pull out all DTC (Diagnostic Trouble Codes), using diagnostic equipment connected to the data link connector of the car. Then you will be full informed about bad pieces (e.g.: front right wheel abs sensor interrupted, ...). After bad pieces replacement you will be able to erase all faults memored by ABS ECU, in other words reset the ABS system and turn off the warning lamp on dashboard.

Have you checked the fuse ??? if so i would suspect wiring . Or the abs ecm mogul

Could be a fuse or a wheel speed sensor; next, check the tone rings on the axle shafts and see if they are not broken.

I quote this information from Jeep lover's...

The amber ABS warning lamp is located in the instrument cluster. It is used to inform the driver that the antilock function has been turned off due to a system malfunction. The warning lamp is controlled by the CAB and/or the main relay through an in-harness diode. The CAB controls the lamp by directly grounding the circuit. The main relay grounds the lamp circuit when it is de-energized.
The re BRAKE warning lamp is located in the instrument cluster. It can be activated by application of the parking brake or leak in the front or rear wheel brake hydraulic circuit.
The antilock brake controller (CAB) is a microprocessor-base device that monitors wheel speeds and controls the anttlock function.
The primary functions of the CAB are:
- monitor wheel speeds
- detect wheel locking tendencies
- control fluid pressure modulation to the brakes during antilock stop operation
- monitor the system for proper operation
- provide communication to the DRB while in diagnostic mode
- store diagnostic information in non-volatile memory
The CAB continuously monitors the speed of each wheel. When a wheel locking tendency is detected, the CAB will command the appropriate valve to modulate brake fluid pressure in its hydraulic unit. Brake pedal position is maintained during an antilock stop by being a closed system with the use of 3 accumulators. The CAB continues to control pressure in individual hydraulic circuits until a wheel locking tendency is no longer present. The CAB turns on the pump/motor during an antilock stop.
The antilock brake system is constantly monitored by the CAB for proper operation. If the CAB detects a system malfunction, it can disable the antilock system and turn on the antilock warning lamp. If the antilock function is disabled, the system will revert to standard base brake system operation.
The CAB inputs include the following:
- four wheel speed sensors
- stop lamp switch
- ignition switch
- main relay voltage
- pump/motor relay output
- diagnostic communication ISO/K
- G switch (acceleration switch)
The ABS main relay is located in the power distribution center (PDC). The main relay has two functions. First, when the relay is energized, it supplies power to the valve/solenoids in the valve block assembly and the pump/motor relay coil. Second, when the relay is de-energized, it supplies a ground to turn on the ABS warning lamp. The main relay is controlled by the CAB. The CAB energizes the main relay when it receives an ignition input signal.
The ABS pump/motor relay supplies power to the pump/motor. It is also located in the PDC. The relay coil is powered by the main relay and the coil ground is controlled by the CAB. The pump/motor relay is a special five-terminal relay and should not be replaced with a standard relay.
One wheel speed sensor (WSS) is located at each wheel and sends a small AC signal to the control module (CAB). This voltage is generated by magnetic induction when a toothed sensor ring (tone wheel) passes by a stationary magnetic sensor (wheel speed sensor). The CAB converts the AC signals into digital signals for each wheel.
The front wheel speed sensor air gap is NOT adjustable. The correct front wheel speed sensor air gap is from 0.40mm to 1.3mm. Preferred rear sensor air gap for drum brake systems is 1.1mm. Acceptable air gap range is 0.92mm to 1.275mm. For rear disc brake systems, the preferred rear sensor air gap is 1.2mm. Acceptable air gap range is 0.95mm to 1.45mm. All wheel speed sensors have a resistance between 900 and 1300 ohms.
Correct antilock system operation is dependent on tone wheel speed signals from the wheel speed sensors. The vehicle's wheels and tires should all be inflated to the recommended pressures for optimum system operation. Variations in wheel and tire size or significant variations in inflation pressure can produce inaccurate wheel speed signals; however, the system will continue to function when using the mini-spare. When driven over rough road surfaces, the rear wheel speed sensor signals may be erratic and cause a false trouble code (drum brakes only).
Diagnostic trouble codes are retained in memory until erased using the DRB, or automatically erased after 50 key cycles.
Ensure you are using a DRBIII scan tool properly connected to the data link connector located under the dash to the right of the steering column.
Select "Anti-lock Brakes" the "Teves ABS". Turn the ignition on.
Read and record all ABS diagnostic trouble codes. If the "Valve Power Feed Circuit" trouble code is present, it must be repaired before prior to addressing any other DTCs.
If there are no trouble codes present, select "Inputs/Outputs" and read the brake switch input as you press and release the brake pedal. If the display does not match the state of the pedal, check for 8 volts at the brake lamp switch output circuit. If the voltage is not present, repair the open brake lamp switch output circuit. If the voltage is present, replace the CAB.
If the display does match the state of the pedal, read the "G-Switch" status, with the vehicle on a level surface, both switches should read "CLOSED". If the status is not correct, make sure the G-Switch is properly mounted and connected (under the driver's side rear seat). If it looks correct, you'll have to check for voltage to the G-Switch.

Hope helps.

ABS/ASC module is faulty
CLASSIC ABS FAILURE SYMPTOMS:
- Most of the time, the problem is the ABS module or one of the 4 wheel speed sensors (& sometimes the brake pressure sensor)
- In my 2002 BMW E39 DSC, three orange (warning) cluster display lights lit, ABS, Brake, & DSC
- The 3 warning lights reset when the ignition is turned off, only to repeatedly reappear within minutes of normal driving
- The fault is often intermittent leading you to falsely believe you've resolved the problem (proper diagnosis is important)
- Sometimes the fault only appears when the engine is hot; other times only at speeds over 40 mph
- Carsoft may erroneously show a rear speed sensor failure; but just replacing the speed sensor may make no difference.
- All the work is in correct diagnosis of the problem; parts replacement is trivial (from 1 to six bolts in a few minutes)
- Hence, this BMW E39 ABS 3-warning light DIY will concentrate on understanding and diagnosis of the problem

Anti-Lock Control —Vehicles Built After 03/2002 The 3-channel anti-lock brake system consists of the following components:

• front wheel speed sensors
• front wheel speed sensor rings
• hydraulic control unit (HCU)
• Anti-lock brake control module (ECU)
• rear wheel speed sensor
• rear wheel speed sensor rings
• yellow anti-lock brake warning indicator

The 4-channel anti-lock brake system with traction control and stability assist system consists of the following components:

• active brake booster with integral solenoid
• brake booster release switch
• front wheel speed sensors
• front wheel speed sensor rings
• hydraulic control unit (HCU)
• stability assist module (ECU)
• stability assist event indicator
• lateral accelerometer
• longitudinal accelerometer (4x4)
• rear wheel speed sensors
• rear wheel speed sensor rings
• steering wheel position sensor
• yaw rate sensor
• yellow anti-lock brake warning indicator
• brake pressure transducer
• traction control switch

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I suspect the abs issue is causing the speed control not to work if it happened at the same time the cruise control stopped working. When the yellow ABS light comes on, it means the ABS is dactivated. You may have a faulty accelerometer which senses acceleration and yaw (side to side lean). I have not seen a bad one but you said it is sensitive to acceleration.
I would unplug it and see what happens. The connector should have a small tab to depress so you can pull the connector out.
Here is where it is:

Accelerometer Removal and Installation

1. NOTE: The accelerometer is located under the center, rear passenger seat carpet. (I think you have to remove seat for access).
   Cut the carpeting along the perforations.

1. Disconnect the electrical connector.

1. Remove the nuts and remove the accelerometer.

Have dealer hook up tester and pull fault codes if you can't find an easy solution.
Some background info

A malfunction in the anti-lock brake system will cause the anti-lock brake control module to shut off or inhibit the system. However, normal power-assisted braking remains.

Malfunctions are indicated by the yellow ABS warning indicator in the instrument cluster.

The anti-lock brake system is self-monitoring. When the ignition switch is turned to the RUN position, the anti-lock brake control module will carry out a preliminary self-check on the anti-lock electrical system indicated by a three-second illumination of the yellow ABS warning indicator in the instrument cluster.

During vehicle operation, including normal and anti-lock braking, the anti-lock brake control module monitors all electrical anti-lock functions and some hydraulic operations.

Each time the vehicle is driven, as soon as vehicle speed reaches approximately 20 km/h (12mph), the anti-lock brake control module turns on the pump motor for approximately one-half second. At this time, a mechanical noise may be heard. This is a normal function of the self-check by the anti-lock brake control module.

Pedal pulsation coupled with noise while braking on loose gravel, bumps, wet or snowy roads is normal and indicates correct functioning of the anti-lock brake system.

Warning Lamp Indicator
The anti-lock brake system (ABS) uses the yellow ABS warning indicator to alert the driver of a malfunctions in the ABS.
The yellow ABS warning indicator will come on to warn the driver that the ABS has been turned off due to a symptom that exists in the ABS. Normal power assist braking remains but wheels can lock during a panic stop while the yellow ABS warning indicator is illuminated.

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Please report back, I am curious if that is what it is. Good luck

This is a (4) four wheel sensor system and more than likely one of them has failed. This will cause ABS module to turn on warning lamp and make the brake pedal 'act up' under the right conditions.This 'acting up' is the ABS system getting a false signal that a wheel is not turning the same as the others when it actually is. Have it scanned for codes and a streaming data scan on a road test under the same conditions that you are experiencing the 'act up' to pinpoint the fault. Hope this helps! Please rate me.