What are the common causes of C0038?

An open or short in the left rear wheel speed sensor supply circuit. Corrosion at the left rear wheel speed sensor connector. A failed left rear wheel speed sensor. A wheel speed sensor that is not fully seated. A fault in the ABS control module supply.

Inspect the left rear wheel speed sensor connector and supply wiring. Check that the left rear wheel speed sensor is fully seated. Test the left rear wheel speed sensor supply voltage. Replace the left rear wheel speed sensor if the supply is good. Test the ABS control module supply output if the fault stays. Clear the code and retest.

C0038

Left Rear Wheel Speed Sensor Supply

System: Chassis control (C code)
Lamp: ABS Light
Category: Chassis

What it means

C0038 means Left Rear Wheel Speed Sensor Supply.

Where it lives

For C0038, start at the sensor the description names.

Check these first

An open or short in the left rear wheel speed sensor supply circuit
Corrosion at the left rear wheel speed sensor connector
A failed left rear wheel speed sensor
A wheel speed sensor that is not fully seated
A fault in the ABS control module supply

What to do next

Inspect the left rear wheel speed sensor connector and supply wiring
Check that the left rear wheel speed sensor is fully seated
Test the left rear wheel speed sensor supply voltage
Replace the left rear wheel speed sensor if the supply is good
Test the ABS control module supply output if the fault stays
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.