C1126moderate severityChassis
Rear Right ABS Sensor Signal Abnormal
on 2020 Subaru Legacy 2.5L H4 · AWD
What this code means
The ABS module is seeing an erratic or out-of-range signal from the rear right wheel speed sensor. Similar to OBD code C0040. This usually points to sensor damage, wiring issues, or a dirty tone ring.
Symptoms
- ABS warning light on
- Traction/stability control disabled
- Speedometer may read erratically
Common causes
- Faulty rear right wheel speed sensor
- Damaged sensor wiring or connector
- Dirty or damaged tone/reluctor ring
- Excessive wheel bearing play
Diagnostic steps
- Scan for stored ABS codes
- Inspect rear right sensor and wiring
- Check tone ring for damage and debris
- Measure sensor output with scope or meter
🔌 Don't have a code reader?
Any of these will read and clear this code — pick by how deep you want to go.
Budget handheld~$40
ANCEL AD410 →
No-phone-needed handheld — reads, clears, live data, freeze frame.
✓ ANCEL official store
Serious DIY~$100
BlueDriver Pro →
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
SHOP FAVORITEShop-grade tablet~$300
Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
✓ Autel official store
Pro diagnostics$1,500+
Autel MaxiSys MS906 Pro →
Full-system pro platform — topology mapping, ECU coding, the works.
✓ Autel official store
As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
Other Chassis codes on this vehicle
C0021
LF Wheel Speed Sensor Range/Performance
C0022
RF Wheel Speed Sensor Range/Performance
C0023
LR Wheel Speed Sensor Range/Performance
C0024
RR Wheel Speed Sensor Range/Performance
C0025
LF Wheel Speed Sensor Circuit Intermittent
C0026
RF Wheel Speed Sensor Circuit Intermittent
C0027
LR Wheel Speed Sensor Circuit Intermittent
C0028
RR Wheel Speed Sensor Circuit Intermittent
C0035
Left Front Wheel Speed Sensor Circuit
C0036
Left Front Wheel Speed Signal Erratic