What C0020 means
There's a problem with the motor that runs the ABS pump. Your regular brakes still work, but anti-lock braking and usually traction and stability control are switched off until it's fixed.
How the engine computer detects it
The ABS control module detects an electrical fault in the pump motor circuit. Without a working pump, the system cannot build hydraulic pressure for ABS or stability control interventions and disables those functions.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Common causes
- Pump motor seized after long inactivity Most likely
- Pump motor relay welded or open Possible
- Power supply connection corroded Possible
How to diagnose C0020
- Check the ABS pump fuse and relay in the underhood fuse box.
- Inspect the ground and power connections at the ABS unit for corrosion.
- A shop with an ABS-capable scanner can command the pump to run. If it doesn't, the pump motor or module has failed.
- Repair is usually replacing the ABS pump and module assembly, then bleeding the brakes with a scanner. Rebuilt units cost far less than new ones.
Vehicles that report C0020 most
| Vehicle | Years | Reports | Share | Median miles |
|---|---|---|---|---|
| Ram 2500 | 2013–2018 | 222 | 41k | |
| Ram 3500 | 2015–2018 | 69 | — | |
| Ram 1500 | 2014–2017 | 5 | — | |
| Mazda Mazda3 | 2010 | 4 | 29k |
Counts of owner complaints to the NHTSA that mention C0020 (302 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.
Reading the code
- C
- Chassis
- 0
- Generic (SAE) code
- 020
- Specific fault
Questions drivers ask
Can I drive with code C0020?
Yes, but brake gently and leave extra distance, especially on wet or icy roads. Without ABS the wheels can lock in a hard stop. If the red brake warning light is on or the pedal feels different, don't drive: have it towed.
Often reported together
Codes that owners mention in the same NHTSA complaints as C0020. They can point to a shared cause, so it's worth checking them together.
- C2200Manufacturer-specific code4 complaints
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.