The front right ride height sensor reports an implausible or missing signal.
Medium severity. Can I keep driving?Drive slowly and avoid long trips if the car is sitting low or behaving strangely.
An electronically controlled suspension uses sensors and actuators to adjust ride height or stiffness. This code indicates a fault in one of them.
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Most likely causes
- Sensor linkage broken
- Sensor failed
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
What each character of C0821 means
- C: Chassis
- 0: Generic code: same on every make
- 8: Subsystem depends on the code range
- 21: Specific fault in that system
Frequently asked questions
Can I keep driving with code C0821?
Drive slowly and avoid long trips if the car is sitting low or behaving strangely.
What causes code C0821?
The most common causes are: sensor linkage broken; sensor failed.
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.