Chassis, generic

C0652 Left Front Wheel Speed Sensor B Range/Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleRequired
Limp modePossible

The second left front wheel speed signal is present but implausible. With two channels per wheel the module has a direct partner to compare: Volvo Truck's patent for a dual-element sensor merges both signals with an integrity index, averages them while they agree within a band, takes the higher value when both run but differ, and drops a channel that reads zero. Bosch's patent for shared wheel sensors lists the usual checks, among them air gap, pulse width and speed plausibility. For single sensors, Toyota, as described by FenderBender, judges plausibility from about 10 km/h forward and flags an 8 km/h gap to vehicle speed; how B is judged is not published. Causes: worn encoder, excessive air gap, wrong part.

Likely causes

Air gap too large from bearing play or a sensor not seated fully
Damaged or contaminated magnetic encoder
Sensor variant not matching the vehicle

Symptoms

  • Driver assistance or redundant braking warning
  • Automated functions withdrawn while ABS on sensor A continues

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–700
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

lf wss btone ring

Related codes

C0651C0653C0654C0655C0656C0501

References: patents.google.com, patents.google.com, fenderbender.com.