Does anyone know when they switched over to the new brake wear sensors? I copied below off one of the tech sites which indicates they changed to a two resistor circuit at some point but didn't indicate when. Once they switched you can no longer just short out the sensors to bypass the brake warning light.
Excerpt: '"New wear sensors have two resistor circuits in parallel at two depths. The first resistor circuit is set at a higher position in the sensor, and the second resistor circuit is at a lower position. When the first resistive circuit is broken, the resistance in the sensor will increase due to the resistors having a parallel structure. When the second wire is broken, the circuit is now open. The first resistive circuit will not typically set a warning light. The information is used by the brake system to estimate the pad life remaining using other information. Called two-stage wear sensors, these are monitored by the ABS module and instrument cluster module on some vehicles.
The system wear sensors use information such as wheel speed, mileage, brake pressure, brake disc temperature and brake operating time to determine the life remaining in the pads. This is displayed in the information center or with a warning lamp that may go from yellow to red. Some systems may show the life left on the pads during start up. The old trick of splicing the wires together to bypass the warning light will not work with two-stage sensors. The module passes voltage through the circuit and uses the amount of voltage drop to confirm the sensor is working. If the system notices that no voltage is dropping across the circuit, it will set a malfunction warning light."
I have a 2003 Z4 with the brake and ABS yellow warning lights coming on but not on a consistent frequency. I was told recently I had 30% life left in my brake pads. Not sure which wheel was being measured by the BMW ISTA but do you think my warning lights are caused by brake pad wear?
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