Chassis, generic

C0655 Left Front Wheel Speed Sensor B Intermittent/Erratic

Check engine lightUsually off
EmissionsNot relevant
Drive cycleRequired
Limp modePossible

C0655 points to a second left front speed signal that drops out or jumps. Active sensors read the wheel through closely spaced sensing elements whose phase-shifted signals also give the rotation direction, as FenderBender explains, so small mechanical faults show up as irregular pulses. HELLA lists the usual reasons a wheel sensor fails: broken wiring, internal shorts, heavy dirt, extra wheel bearing play and a damaged encoder. Volvo Truck's dual-element design discards a channel that reads zero and carries on with the other. Bosch stresses that the redundant signal must be permanently available to avoid delays when the backup actuator takes over. GM's PIP5094 lists C0655 only as an unrelated old GM number.

Likely causes

Loose contact or partly broken wire that moves with the steering and suspension
Dirt or damage on the magnetic encoder
Excessive wheel bearing play changing the air gap

Symptoms

  • Warning that comes and goes, often on rough roads or while steering
  • Automated or redundant brake functions intermittently withdrawn

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 ringsensor wiring

Related codes

C0651C0652C0653C0654C0504C065C

References: fenderbender.com, hella.com, patents.google.com, bosch-mobility.com.