Chassis, generic

C0038 Left Rear Wheel Speed Sensor Supply

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

Covers the supply circuit that powers the left rear active wheel speed sensor, the rear-axle counterpart of C0032. Active sensors need a regulated voltage from the ABS/ESC module; this code is set when that supply is open, shorted to ground or to another voltage, or outside the regulated range so the sensor cannot produce a valid signal. Ford lists C0038 with C0037 on 2020-2022 F-53 and F-59 chassis where a bent or damaged sensor and its circuit set an ABS light. A fault disables ABS, traction and stability control for that corner and lights the ABS warning lamp while base braking remains; it is distinct from the sensor-signal code C0037 in that the feed itself is faulty.

Likely causes

Open or shorted sensor supply wire
Corroded connector on the supply side
Module sensor supply output fault

Symptoms

  • ABS warning lamp on
  • ABS and stability control disabled
  • No wheel speed signal from this corner

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–450
Time0.5–2 h

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

Parts involved

lr wsssensor supply

Related codes

C0037C0032C003B

References: static.nhtsa.gov, en.wikipedia.org.