A Shanghai Passat B52.8 sedan, the user reflects the car on the dashboard of the ABS, ESP fault warning light is always lit, and said a week ago due to the instrument panel on the ABS, ESP fault warning light and often replaced the brake Light switch.
    Maintenance personnel to connect the fault diagnosis instrument V.A.G1552 on the vehicle's braking system to detect and found the "00526027 - brake light switch unreliable signal" fault code. Use the fault diagnosis instrument into the data stream (08) 005 group observation data changes, when the foot gently step on the brake pedal makes the brake light just light, the device shows the braking pressure of 1.4MPa, this data has been far Far beyond the maintenance manual required technical parameters (0.2MPa below). Based on this diagnostic results, the author re-removed the brake light switch, and in accordance with the installation specifications (attached) re-installed. After that, the author once again observe the data stream in the 08-005 group 3 area data, has been in line with the maintenance manual technical requirements.
    After clearing the fault code, start the engine again, the ABS on the dashboard, the ESP fault warning light is no longer lit. Through this failure, prompting us to carry out maintenance, must be in strict accordance with the requirements of manufacturers maintenance manual to do.
    Attachment: brake light switch installation.
    (1) Before the installation of the brake light switch housing rotation to the position shown in Figure 1, if the parts have been in this position do not have to do this operation, pay attention to the application of the first hand before the push rod in the end.
    (2) Pull the plunger to the longest position and apply a little Vaseline or Lubricant (the ejector and jacking of the mandrel must keep the brake light switch at the position of the disassembly, ie the position shown in Figure 2 , If hard pull will damage the brake light switch).
    (3) Place the brake light switch in the mounting hole of the brake pedal frame, where the ejector lever is pushed back by the brake pedal and the plunger is adjusted to the appropriate length according to the height of the brake pedal.
    (4) Turn the brake light switch housing clockwise by 45 ° by hand.
    (5) with a few times the pedal brake pedal, check the brake light is able to work properly. If the brake light is working properly and the installation is complete, if the brake light does not work properly, remove the brake light switch to check if the brake light is off due to improper installation and check the corresponding line and fuse.