Code
C0045
DAEWOO
C — Chassis
Left rear wheel speed sensor circuit malfunction
Views:
UK: 2
EN: 14
RU: 12
AI status
Completed
Completed
100%
Causes
- Damaged or contaminated wheel speed sensor
- Broken, chafed or corroded wiring or connector to the sensor
- Loose or corroded connector pins
- Damaged or missing tone ring (reluctor) or foreign material between sensor and ring
- Faulty ABS/traction control module or poor ground
- Short to voltage or ground in the sensor circuit
Symptoms
- ABS warning lamp illuminated
- Traction control/ESC warning or reduced functionality
- Left rear wheel speed reading erratic or zero in live data
- Unwanted ABS activation or loss of anti-lock braking function under braking
- Possible speedometer/vehicle speed inconsistencies on some models
What to check
- Use a scan tool to read ABS/traction control live data and confirm left rear wheel speed reading vs other wheels.
- Visually inspect sensor, wiring harness and connector for damage, corrosion or contamination.
- Check connector for proper seating and bent or pushed-back pins.
- Spin the wheel by hand (vehicle safely supported) and observe live wheel speed value or measure sensor signal.
- Measure sensor resistance and compare to specification.
- Backprobe connector and check for reference voltage (if active sensor) or AC output (if passive) while spinning wheel.
Signal parameters
- Passive (variable-reluctance) sensors: DC resistance typically ~500–1500 Ω (model dependent); AC voltage rises with speed (tens to hundreds of millivolts at low speed up to volts at higher speed).
- Active (Hall) sensors: provide a digital/pulse signal, often 0–5 V or 0–12 V square wave; reference/ground supply typically 5–12 V from ABS module.
- Pulse frequency proportional to wheel speed; expect smooth, regular waveform without dropouts when wheel is rotated.
- Expected waveform at connector: clean sinusoidal/AC for passive sensors or square/pulse for active sensors; intermittent, clipped or absent waveform indicates fault.
Diagnostic algorithm
- Confirm fault with a scan tool and record freeze frame/live data for left rear wheel speed.
- Visually inspect left rear sensor, housing, tone ring and wiring for damage, dirt or metal shavings; clean sensor and tone ring if contaminated.
- With vehicle safely supported, spin the left rear wheel and observe wheel speed value in the scan tool to confirm missing/erratic signal.
- Disconnect sensor connector and inspect pins for corrosion, bent pins or water ingress.
- Measure sensor resistance with an ohmmeter (compare to factory spec). An open or short indicates sensor replacement.
- For passive sensor: backprobe sensor connector and spin wheel; measure AC voltage with a multimeter or oscilloscope. For active sensor: check reference voltage at connector (typically 5–12 V) and measure output waveform while spinning.
- Wiggle wiring and connectors while monitoring signal to find intermittent faults; check continuity from sensor connector to ABS module pins to rule out open circuits.
- Inspect tone ring for cracks, missing teeth, heavy corrosion or foreign material; repair or replace if damaged.
- Repair or replace damaged wiring, connector or sensor as required. After repairs clear codes, perform a test drive and re-scan to confirm the fault does not return.
- If wiring and sensor are good but no signal at the ABS module, test module inputs and grounds; consider module repair/replacement only after wiring and sensor verified good.
Likely causes
- Dirty or damaged sensor air gap/tone ring interference
- Open or short in the sensor wiring or poor connector contact
- Failed wheel speed sensor element (magnetic or Hall)
- Corroded connector or grounding problem
Fault status
Status
ABS/traction control module detected a malfunction in the left rear wheel speed sensor circuit; ABS warning lamp stored and vehicle stability systems may be limited.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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