ABS fault 4206 - left front speed sensor

[Jeremy Cottrell]

On a 98 Boxster 5-speed, the code 4206 keeps coming back after replacing the left front speed sensor, double checking the wiring connection and even installing a new battery. Are we looking at a bad control unit? Has anyone out there had this problem?

[Loren]

On a 98 Boxster 5-speed, the code 4206 keeps coming back after replacing the left front speed sensor, double checking the wiring connection and even installing a new battery. Are we looking at a bad control unit? Has anyone out there had this problem?

DTC 4206

Front left speed sensor, signal implausible

Possible faults (cause in the event of deviation):

1. Air gap between speed sensor and gear wheel (pulse wheel) too large or, due to wear (chip formation), too small (check installation).

2. Pulse wheel defective or corroded.

3. Wheel bearing damage (wheel bearing not adjustable).

4. Plug connection in wiring from the speed sensor to the control module or PIN on the control module connector not OK.