C1A33

Code

Generic C — Chassis

Right Rear Wheel Speed Sensor Circuit Range/Performance

Brand: Generic

Type: C — Chassis

Views: UK: 11 EN: 21 RU: 25

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Failed right rear wheel speed sensor
Damaged or chafed wiring harness between sensor and ABS/ECU
Corroded or loose connector at sensor or ECU
Missing, cracked, or contaminated tone ring (reluctor)
Excessive sensor air gap or incorrect sensor alignment
Wheel bearing contamination or magnetic debris on tone ring

Symptoms

ABS warning lamp and/or traction control/ESC light illuminated
Intermittent or false ABS activation during braking
Loss of traction control or stability functions
Inconsistent or missing wheel speed reading in scan tool live data for right rear
Possible speedometer/odometer effects on some vehicle systems

What to check

Read freeze frame and complete fault list with a capable scan tool; note related codes
Compare live wheel speed readings (all four wheels) at low speed
Perform visual inspection of right rear sensor, tone ring, wiring and connector for damage, corrosion, or contamination
Wiggle test wiring while monitoring live data to reproduce the fault
Measure sensor resistance and check continuity to the ABS/ECU connector
Check supply/reference voltage and ground at the sensor (for active/Hall sensors)

Signal parameters

Passive (magnetic) pick-up sensors: produce AC sine waveform; amplitude and frequency increase with wheel speed. Typical DC resistance often in the hundreds to low thousands of ohms (vehicle-specific).
Active (Hall/VR with electronics) sensors: produce a pulsed square or digital signal referenced to a supply (commonly 5 V or vehicle battery depending on design).
Expected characteristics: clean, consistent waveform proportional to speed; no constant high or low voltage, no excessive noise, and no intermittent dropouts.
Exact voltage, resistance and waveform shape are vehicle- and sensor-type dependent—consult manufacturer specifications before replacing parts.

Diagnostic algorithm

Verify code and capture freeze frame. Check for recent repairs or physical damage in the right rear area.
Clear code, then perform a short road test while monitoring right rear wheel speed live data to confirm repeatability.
Visually inspect sensor, connector and tone ring. Clean any debris and correct obvious faults.
Backprobe the sensor connector: for passive sensor measure DC resistance; for active sensor check reference voltage, ground and signal while cranking/wheel rotation.
Wiggle the harness and connectors while watching live data or oscilloscope for intermittent changes.
Use an oscilloscope at the sensor to view waveform while rotating the wheel. Look for missing pulses, noise, or amplitude collapse.
Inspect tone ring for missing/chipped teeth, rust, or magnetic debris. Repair or replace if damaged.
If wiring/connector tests fail, trace and repair wiring to the ABS module; verify continuity and repair any shorts to ground/voltage.
Replace sensor only after confirming sensor or tone ring is faulty. After repair, clear codes and confirm with road test and live data/oscilloscope that waveform and speeds are stable.
If all wiring and sensor tests are good and code persists, consider module input fault and test/replace ABS/ESC module per manufacturer procedures.

Likely causes

Sensor fault (most common)
Connector corrosion or poor contact
Damaged tone ring or magnetic debris interfering with signal
Wiring harness open/short or intermittent connection

Fault status

⚠️ Status

Right Rear Wheel Speed Sensor Circuit — signal outside expected range or intermittent. ABS/traction control may be disabled or operate incorrectly until the fault is corrected.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1-3 hours