Code
C0252
Generic
C — Chassis
ABS Wheel Speed Sensor Circuit Fault (Sensor 2)
Views:
UK: 1
EN: 0
RU: 0
AI status
Completed
Completed
100%
Causes
- Faulty wheel speed sensor (Sensor 2)
- Open or shorted wiring between sensor and ABS module
- Corroded, loose or contaminated connector
- Damaged or missing tone/ring reluctor on the wheel/hub
- Damaged wheel bearing or excessive air gap altering the signal
- Faulty ABS control module or poor ground/shielding
Symptoms
- ABS warning lamp ON (may also show traction/ESC lamp)
- ABS or traction control disabled (reduced braking performance under ABS events)
- Intermittent ABS/traction warnings when cornering or over bumps
- Possible inconsistent wheel speed reading in live data
- Occasional ABS activation when not required (rare)
What to check
- Retrieve and record freeze-frame and live-data for all ABS wheel speed sensors
- Identify which wheel is Sensor 2 for the specific vehicle application
- Visual inspection of sensor, connector and wiring for damage, corrosion or foreign material
- Compare live wheel speed readings for Sensor 2 vs opposite wheel while rotating wheel
- Check for presence of tone/reluctor and inspect for damage or missing teeth
- Measure sensor resistance and continuity to the ABS module connector
Signal parameters
- Sensor types: passive (variable reluctance/VR) or active (Hall/active magnetic) — verify vehicle type
- Passive VR typical DC resistance (generic): ~800–2,000 ohms (varies by design) — open/infinite indicates break
- Passive VR output: AC voltage that increases with wheel speed; low speeds produce tens to hundreds of mV, higher speeds produce volts
- Active sensor: 5 V reference supply; output is a square/pulse ~0–5 V (or 0–12 V on some systems) proportional to speed
- Typical static: 0 V output at rest (active) or 0 mV (passive); waveform frequency increases with wheel rotation speed
- Continuity: short to ground or to power will show low ohms; open shows very high/infinite
Diagnostic algorithm
- Read and record current ABS codes and freeze-frame data. Note vehicle speed and conditions when fault set.
- Confirm which wheel is Sensor 2 from manufacturer documentation or wiring diagrams.
- Visually inspect the sensor, connector and harness for damage, corrosion, loose clips, rubbing or crushed wiring.
- Backprobe connector with ignition ON: check for correct reference voltage (if active sensor) and good ground.
- Measure sensor DC resistance (for passive sensor) and compare to specification; open or short indicates faulty sensor.
- With wheel lifted and safe supports in place, spin the wheel and observe live data for Sensor 2 vs the opposite wheel using a scan tool.
- Use a multimeter set to AC mV (for VR) or a scope (recommended) to observe waveform while wheel is rotated; look for clean waveform without dropouts or noise.
- Wiggle harness and connectors while monitoring live data to reveal intermittent faults. Inspect tone ring for missing or damaged teeth and clean if contaminated.
- If wiring fault suspected, perform continuity and short-to-power/ground tests between sensor connector and ABS module connector; repair any damaged wiring or connector pins.
- Replace sensor or tone ring if found defective. If wiring and sensor are good but no signal at ABS module input, consider module fault and confirm power/ground to module before replacement.
- Clear codes and perform a test drive to verify the fault does not return and that ABS/traction function is restored.
Likely causes
- Sensor damaged by road debris or corrosion
- Connector pin corrosion or poor connection at sensor
- Broken or chafed harness near wheel or suspension
- Reluctor (tone) ring cracked, missing teeth or contaminated
Fault status
Status
C0252 — ABS Wheel Speed Sensor Circuit Fault (Sensor 2). The ABS control module has detected an implausible, missing, open or shorted wheel speed sensor signal for Sensor 2. ABS/traction control may be limited or disabled.
Repair difficulty: Medium
Diagnostic time: 1.5-3.0 hours
Similar codes
Workshop Manuals
Available brands with manuals
1
LAND ROVER 2
Land Rover Defender 300Tdi — Workshop Manual (1996 model year)
Workshop ManualOfficial workshop manual for the Land Rover Defender 300Tdi (from 1996 model year). Contains specifications, adjustment, fault diagnosis and step-by-step repair and overhaul procedures for engine, transmission, axles, suspension, brakes, electrical and body. Intended for dealer workshops and trained technicians.
199,00 UAH
Land Rover Defender Workshop Manual Supplement & Body Repair Manual (1999 & 2002 MY)
Workshop ManualWorkshop Manual Supplement and Body Repair Manual for the Land Rover Defender. Includes general specifications, maintenance schedules, tuning data and step‑by‑step repair procedures for engine, transmission, suspension, brakes, electrical and body repairs. Covers Defender models from 1999 and 2002 model years.
199,00 UAH
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email
Code
C0252
OPEL
C — Chassis
ECU in Delivery State or Defective ECU
Views:
UK: 6
EN: 7
RU: 3
AI status
Completed
Completed
100%
Causes
- Faulty wheel speed sensor (Sensor 2)
- Open or shorted wiring between sensor and ABS module
- Corroded, loose or contaminated connector
- Damaged or missing tone/ring reluctor on the wheel/hub
- Damaged wheel bearing or excessive air gap altering the signal
- Faulty ABS control module or poor ground/shielding
Symptoms
- ABS warning lamp ON (may also show traction/ESC lamp)
- ABS or traction control disabled (reduced braking performance under ABS events)
- Intermittent ABS/traction warnings when cornering or over bumps
- Possible inconsistent wheel speed reading in live data
- Occasional ABS activation when not required (rare)
What to check
- Retrieve and record freeze-frame and live-data for all ABS wheel speed sensors
- Identify which wheel is Sensor 2 for the specific vehicle application
- Visual inspection of sensor, connector and wiring for damage, corrosion or foreign material
- Compare live wheel speed readings for Sensor 2 vs opposite wheel while rotating wheel
- Check for presence of tone/reluctor and inspect for damage or missing teeth
- Measure sensor resistance and continuity to the ABS module connector
Signal parameters
- Sensor types: passive (variable reluctance/VR) or active (Hall/active magnetic) — verify vehicle type
- Passive VR typical DC resistance (generic): ~800–2,000 ohms (varies by design) — open/infinite indicates break
- Passive VR output: AC voltage that increases with wheel speed; low speeds produce tens to hundreds of mV, higher speeds produce volts
- Active sensor: 5 V reference supply; output is a square/pulse ~0–5 V (or 0–12 V on some systems) proportional to speed
- Typical static: 0 V output at rest (active) or 0 mV (passive); waveform frequency increases with wheel rotation speed
- Continuity: short to ground or to power will show low ohms; open shows very high/infinite
Diagnostic algorithm
- Read and record current ABS codes and freeze-frame data. Note vehicle speed and conditions when fault set.
- Confirm which wheel is Sensor 2 from manufacturer documentation or wiring diagrams.
- Visually inspect the sensor, connector and harness for damage, corrosion, loose clips, rubbing or crushed wiring.
- Backprobe connector with ignition ON: check for correct reference voltage (if active sensor) and good ground.
- Measure sensor DC resistance (for passive sensor) and compare to specification; open or short indicates faulty sensor.
- With wheel lifted and safe supports in place, spin the wheel and observe live data for Sensor 2 vs the opposite wheel using a scan tool.
- Use a multimeter set to AC mV (for VR) or a scope (recommended) to observe waveform while wheel is rotated; look for clean waveform without dropouts or noise.
- Wiggle harness and connectors while monitoring live data to reveal intermittent faults. Inspect tone ring for missing or damaged teeth and clean if contaminated.
- If wiring fault suspected, perform continuity and short-to-power/ground tests between sensor connector and ABS module connector; repair any damaged wiring or connector pins.
- Replace sensor or tone ring if found defective. If wiring and sensor are good but no signal at ABS module input, consider module fault and confirm power/ground to module before replacement.
- Clear codes and perform a test drive to verify the fault does not return and that ABS/traction function is restored.
Likely causes
- Sensor damaged by road debris or corrosion
- Connector pin corrosion or poor connection at sensor
- Broken or chafed harness near wheel or suspension
- Reluctor (tone) ring cracked, missing teeth or contaminated
Fault status
Status
C0252 — ABS Wheel Speed Sensor Circuit Fault (Sensor 2). The ABS control module has detected an implausible, missing, open or shorted wheel speed sensor signal for Sensor 2. ABS/traction control may be limited or disabled.
Repair difficulty: Medium
Diagnostic time: 1.5-3.0 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email