C0022
ABS Pump Motor Circuit Low
Voltage on the pump motor control line is below threshold. Typical causes are a short to ground or interrupted positive supply.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: medium
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Common causes
Ordered by how often each turns out to be the cause.
- Wiring shorted to groundCommon
- Pump motor relay failedPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- ABS Pump Motor
- Pump Motor Relay
- Power Supply Wiring
C0022 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.