P0723

Code

GWM P — Powertrain

- Malfunction of the shaft speed sensor

Brand: GWM

Type: P — Powertrain

Views: UK: 0 EN: 1 RU: 0

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Page language: EN

Causes

Faulty output/shaft speed sensor
Damaged, corroded or loose wiring/connectors in the sensor circuit
Poor ground or reference supply to the sensor
Contaminated or damaged reluctor/tone ring (missing or broken teeth)
Intermittent connection from vibration or harness chafing
Faulty Transmission Control Module (TCM) or PCM software/firmware

Symptoms

Check Engine / MIL lamp illuminated
Erratic or no vehicle speed reading and/or speedometer malfunction
Harsh or erratic transmission shifting, or transmission stuck in limp mode
Cruise control disabled
Poor drivability or unexpected engine RPM behavior while moving
Stored related transmission/vehicle speed codes

What to check

Connect a scan tool, record freeze-frame and live data for output/shaft speed PID(s)
Compare engine RPM versus vehicle speed to identify missing/erratic shaft speed signal
Visually inspect sensor connector and harness for corrosion, damage, or water intrusion
Wiggle harness and connectors while monitoring live data to find intermittent faults
Back-probe sensor connector to check reference voltage, ground, and signal with key on/engine running
Check continuity and resistance of sensor circuit to the TCM; check for shorts to ground/12V

Signal parameters

Sensor types: Hall-effect (active) or magnetic pickup (passive) depending on design
Active (Hall) sensor: requires 5V reference and ground; output is a 0–5 V square/pulse signal (duty ~50%) with frequency proportional to shaft speed
Passive (magnetic) sensor: generates AC sine-wave pulses; amplitude and frequency increase with speed (typical idle-range millivolt to volt levels)
Signal frequency proportional to shaft rotation speed — should be steady, proportional to vehicle speed
Expected behavior: clean, repeating pulses without dropouts, noise, or long pauses

Diagnostic algorithm

Safety: Park on level ground, chock wheels, apply parking brake. Use appropriate PPE.
Read and record all stored codes and freeze-frame data with a scan tool.
Monitor live OSS (output/shaft speed) PID while someone slowly rotates the drive wheels (or perform a controlled road test) and observe for a clean, proportional signal.
Visually inspect the sensor, connector, and wiring. Unplug connector and inspect for corrosion, bent pins, or contamination.
Back-probe the sensor with key on (engine off) to verify reference voltage (active sensor) and ground presence. Typical reference is 5V for Hall sensors.
With vehicle in neutral and safe to do so, measure the sensor output while rotating the shaft/wheel: use an oscilloscope to verify waveform (preferred) or check AC voltage for passive sensors with a DMM.
Check continuity and resistance between the sensor connector and the TCM; check for shorts to power or ground.
Inspect the reluctor/tone ring for damage, missing teeth, or metal debris interfering with sensor air gap.
If wiring and reluctor are good, replace the sensor and clear codes. Re-test to confirm the signal and perform a road test.
If problem persists after sensor replacement, consider TCM/PCM inputs and grounding; consult manufacturer service information for TCM diagnostics and software updates.

Likely causes

Sensor connector corroded or loose at the transmission
Open or short in the sensor wiring between sensor and TCM
Magnetic/reluctor ring damaged or covered in metal shavings/contamination
Failed hall-effect or magnetic pickup sensor
Intermittent ground or low reference voltage to the sensor

Fault status

⚠️ Status

Output/shaft speed sensor circuit malfunction detected — signal missing, out of range, or intermittent. Inspect sensor, wiring/connectors, tone ring, and transmission control module.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1-3 hours

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P0723 — - Malfunction of the shaft speed sensor