HM TECH Wheel Speed Sensor ABS Brake Sensor Cable User Manual

Features

• High detection accuracy, fast response speed (signal delay less than 2ms), ensuring the ABS control unit can obtain real-time and accurate wheel speed data for timely braking adjustment.
• Strong anti-interference ability, effectively resisting electromagnetic interference from the motorcycle’s electrical system and external environment, ensuring stable signal output even in complex riding conditions.
• IP67 waterproof and dustproof performance, adapting to harsh riding environments such as rain, dust, mud, and road debris, preventing water and dust from entering the sensor and causing damage.
• High temperature and vibration resistance, able to work stably under high-temperature environments (up to 150℃) and strong vibration during motorcycle riding, with good structural stability.
• Compact and lightweight design, easy to install and match with various motorcycle wheel hub structures, adopting high-quality magnetic materials and a precision manufacturing process, with long service life.
• Direct fit design, compatible with most original motorcycle interfaces, no need to modify the vehicle structure, reducing installation difficulty.

Installation Instructions

Installation Preparation

Before installation, turn off the motorcycle’s power supply and remove the ignition key to avoid electrical shock or component damage. Prepare necessary tools (8-10mm socket wrench, screwdriver, non-magnetic feeler gauge, compressed air, lint-free cloth, brake cleaner, Loctite 243 thread locker, etc.). Check whether the sensor model matches the motorcycle model (including front/rear wheel distinction), and inspect the sensor for damage, deformation, wire breakage or missing parts. Clean the installation position (wheel hub, sensor mounting bracket and pulse ring) to remove dust, oil stains, metal shavings and rust, which may affect the detection accuracy and installation fit. Check the pulse ring (toothed ring) for tooth damage, deformation or rust, and replace it if necessary.

Mounting Steps

1. Locate the designated installation position of the motorcycle (front wheel hub near the brake disc or rear wheel hub near the sprocket), align the sensor’s mounting hole with the motorcycle’s fixing bracket hole, and ensure the sensor probe is aligned with the pulse ring (toothed ring) on the wheel hub.
2. If the sensor is equipped with an O-ring or sealing gasket, install it on the sensor’s mounting end, apply a small amount of engine oil or grease to the O-ring to ensure a good seal and facilitate installation, and check that the O-ring is undamaged and correctly positioned.
3. Screw the sensor into the mounting bracket by hand first, then use a socket wrench to tighten the fixing bolt to the specified torque (usually 6-8 N·m, refer to the motorcycle’s torque specification), apply Loctite 243 thread locker to the bolt if necessary to prevent loosening during riding, and do not overtighten to avoid cracking the sensor body or damaging the mounting bracket.
4. Adjust the sensor gap: Use a non-magnetic feeler gauge to measure the gap between the sensor tip and the pulse ring (toothed ring), the ideal gap is between 0.3 mm and 1.0 mm (max 1.85 mm for some models), which is narrow enough that a bank card cannot be inserted. If the gap is not within the specified range, use a thin shim to adjust the sensor position slightly or adjust the mounting bracket to ensure the gap meets the requirement.
5. Route the sensor’s signal wire along the motorcycle’s frame and brake hose, fix it with cable clips to avoid the wire being squeezed, worn or entangled with the wheel, brake disc or other moving parts. Ensure the wire has a proper slack to avoid pulling or breaking when the wheel turns.
6. Connect the sensor’s electrical connector to the corresponding interface of the motorcycle’s ABS control unit or wiring harness, press the release tab until a distinct click is heard to ensure a firm connection, and avoid pulling the wires forcibly to prevent wire breakage or poor contact. Protect the connector from water and dust intrusion.
7. Reinstall the removed parts (such as wheel, brake disc, fender), and check the sensor’s installation status and wire routing again to confirm that there are no omissions or errors.

Post-installation TestTurn on the motorcycle’s power supply, insert the ignition key and start the motorcycle. Observe the ABS indicator light on the instrument panel: the indicator light should turn on when the power is turned on and go off shortly after the motorcycle starts moving (usually when the speed reaches 5 km/h or more), indicating the sensor and ABS system are working normally. Ride the motorcycle at a low speed (20-30 km/h), gently step on the brake pedal to check whether the ABS system is activated (you can feel slight vibration of the brake pedal), and observe whether the wheel speed signal is stable through the instrument panel (if equipped). Run the motorcycle at different speeds and test the brake performance under different conditions to verify that the sensor can stably transmit wheel speed signals. If any abnormality is found (such as ABS indicator light remains on, no ABS activation, unstable signal), stop the motorcycle immediately, turn off the power supply, and check the installation gap, wiring connection, pulse ring and sensor integrity, then troubleshoot in time. After installation, perform a learning process if required: pinch the brake switch, turn on the ignition switch and repeat 8 times, then ride to 50 km/h and slow down to stop, until the ABS indicator light goes out.

Operation

1. Start the motorcycle according to the normal startup procedure; the ABS sensor will be activated automatically and start detecting the wheel speed signal, which is transmitted to the ABS control unit in real time.
2. During riding, the ABS control unit monitors the wheel speed in real time through the sensor signal. When emergency braking or braking on wet and slippery roads, if the wheel is about to lock, the control unit will quickly adjust the brake pressure (up to 20 times per second) to keep the wheel slip rate between 10% and 30%, ensuring the motorcycle maintains direction control while achieving the best braking effect.
3. The operator can observe the ABS indicator light on the instrument panel to grasp the working status of the sensor and ABS system: if the indicator light is off during riding, it means the system is normal; if the indicator light is on or blinking, it indicates a fault in the sensor or ABS system, and the ABS function may be invalid (the conventional braking system still works normally).
4. If the ABS indicator light is blinking, it may indicate that the ABS system is in low voltage mode (insufficient battery voltage); turn off the ignition switch, charge the battery, and restart the motorcycle to check whether it returns to normal. If the fault persists, perform troubleshooting according to the relevant section of this manual.
5. After the motorcycle stops working, turn off the power supply; the ABS sensor will stop working automatically, and the ABS control unit will record the last working data for subsequent maintenance reference.

Notes

• Do not install the sensor in a position that is easy to collide with external objects or is exposed to excessive friction, so as not to damage the sensor body, probe or signal wire.
• During installation and operation, do not touch the sensor’s detection probe with metal objects, do not knock or scratch the probe, so as not to damage the magnetic element inside the probe and affect the signal output accuracy.
• Do not reverse the positive and negative poles of the sensor’s power supply during wiring (if applicable), otherwise it will burn the sensor’s internal circuit and affect the normal operation of the ABS system.
• Regularly clean the sensor’s probe and pulse ring (toothed ring) to avoid dust, oil stains, metal shavings or iron deposits covering the probe or blocking the pulse ring slots, which may cause signal distortion, no signal output or unstable signal.
• Avoid using the sensor in an environment with extremely high temperature (exceeding 150°C) or extremely low temperature (below -40°C) for a long time, so as not to damage the internal electronic components and shorten its service life.
• Do not disassemble the sensor without permission; if the sensor is faulty or damaged, replace it with a model that matches the motorcycle, and do not use incompatible sensors to avoid damage to the ABS control unit or failure of the ABS system. It is recommended to use original accessories to reduce fault recurrence rate.
• During maintenance or replacement, ensure the motorcycle is parked stably, turn off the power supply and remove the ignition key, and support the motorcycle with a stand to avoid accidental movement and personal injury. Do not perform maintenance when the brake system is hot.
• When cleaning the motorcycle, avoid directly flushing the sensor and its connector with high-pressure water to prevent water from entering the internal circuit and causing short circuit.
• Do not modify the sensor’s signal wire or mounting position without permission, which may affect the detection accuracy and lead to ABS system failure.

Maintenance

• Daily maintenance: After each use of the motorcycle, wipe the sensor’s surface and probe with a lint-free cloth to remove dust, oil stains and other impurities; check the sensor’s wiring and connector for looseness, oxidation, damage or water intrusion, and tighten, clean or dry it in time. Check the pulse ring for dirt or damage.
• Regular maintenance (every 2000-3000 kilometers or 3 months): Check the sensor’s installation gap, adjust it if it is out of the specified range; check the O-ring or sealing gasket for aging or damage, and replace it in time to ensure the seal; use compressed air to clean the pulse ring slots to avoid debris accumulation; check the signal wire for wear or breakage, and replace it if necessary.
• Long-term storage: If the motorcycle is not used for a long time, disconnect the sensor’s electrical connector, clean the sensor and installation position, and store the motorcycle in a dry, cool and dust-free environment to avoid moisture, corrosion or dust accumulation affecting the sensor’s performance. The sensor should be stored in multi-layer anti-static packaging to avoid electromagnetic interference.
• Professional inspection: Every 10000 kilometers, ask professional technicians to inspect the sensor’s performance and internal circuit, use an oscilloscope to detect the signal waveform (normal waveform is continuous sine wave), and replace the sensor in time if any potential fault is found. Use a wireless tester or cloud-based diagnosis platform for quick fault detection if available.

Troubleshooting

• ABS indicator light remains on after startup: Check whether the sensor’s wiring is loose, disconnected or short-circuited; check whether the sensor’s probe is blocked by dust, oil stains or metal shavings; check whether the sensor is damaged (measure the resistance between the sensor pins: the normal resistance of two-wire sensors is 800~2300 Ω, if it exceeds the range, the sensor is damaged); check whether the pulse ring (toothed ring) is worn, deformed, rusted or has missing teeth; check whether the installation gap is within the specified range.
• No ABS activation during braking: Check whether the sensor’s signal wire is broken or poorly connected; check whether the ABS control unit is faulty; check whether the brake system pressure is normal; check whether the sensor’s probe is misaligned with the pulse ring.
• Unstable ABS operation (abnormal vibration of brake pedal): Check whether the sensor’s installation gap is too large or too small; check whether the pulse ring is dirty or damaged; check whether the sensor’s internal electronic circuit is faulty; check whether the wiring is interfered by external factors.
• Sensor fault code displayed (such as DTC 1-1, 1-2 for front wheel sensor abnormality): Use an OBD diagnostic tool to read the fault code, check the corresponding circuit and sensor according to the fault code; check whether the sensor is improperly installed or loose; check whether the wiring harness is defective or the connector is in poor contact; erase the fault code after troubleshooting and test-ride the motorcycle to confirm the fault is eliminated.
• Sensor damage: If the sensor is damaged (no resistance, short circuit or open circuit), replace it with a new sensor of the same model, re-adjust the installation gap and wiring connection, then perform a post-installation test. Replace the pulse ring at the same time if it is damaged to avoid secondary damage to the new sensor.