Decompose pictures
| Reference Number | Part Name | Description & Function |
|---|---|---|
| 1 | Sensor Body (Iron Housing) | High-strength iron/steel cylindrical main body with precision-machined mounting flange. Provides robust protection and precise alignment with the sensing target. |
| 2 | Magnetic Pickup / Hall Effect Element | Sealed electromagnetic or Hall effect sensing element at the sensor tip. Detects gear teeth or target wheel rotation and generates a corresponding electrical pulse signal. |
| 3 | Rubber O-Ring / Sealing Gasket | Oil and temperature-resistant Viton/Nitrile rubber seal on the mounting flange. Ensures a leak-proof interface with the engine or hydraulic component housing. |
| 4 | Electrical Connector Socket | Industry-standard sealed multi-pin connector interface. Accepts the Hyundai wiring harness plug for signal output, ground, and power supply. |
| 5 | Terminal Pins | Gold or tin-plated brass conductor pins inside the connector socket. Provide corrosion-resistant, vibration-proof electrical continuity for accurate pulse signal transmission. |
| 6 | Internal Signal Conditioning Circuit | Miniature encapsulated electronic PCB (if active Hall type). Converts magnetic field changes into a clean square wave digital pulse output proportional to rotational speed. |
| 7 | Mounting Flange & Bolt Hole | Precision-machined mounting bracket with bolt hole. Allows secure fastening to the flywheel housing, engine block, or hydraulic motor at the correct air gap. |
| 8 | Connector Locking Mechanism | Integrated locking tab or spring clip on the connector socket. Ensures the mating harness plug remains firmly engaged under severe vibration and harsh conditions. |
Parts list
| Item | OEM Reference No. | COGENG Part No. | Description | Qty |
|---|---|---|---|---|
| 1 | 21E3-0042 | CG-21E3-0042 | Hyundai Revolution Speed Sensor — Complete Assembly (Iron Body + Rubber Seal) | 1 |
| 2 | — | CG-SEAL-21E3 | Replacement Rubber O-Ring / Sealing Gasket | 1 Set |
| 3 | — | CG-CONN-HY-3P | Replacement Wiring Harness Connector Plug with Terminals & Seals | 1 (Optional) |
| 4 | — | CG-SPACER-SS | Sensor Air Gap Adjustment Spacer / Shim Kit | 1 Set (Optional) |
Decompose pictures
Cross-Reference Compatibility Table
| Brand | Compatible Part Number | Typical Hyundai Models | Notes |
|---|---|---|---|
| COGENG | CG-21E3-0042 | R210LC-7, R140LC-7, R160LC-3, R160LC-7, R180LC-7 | Primary COGENG Part Number |
| Hyundai (OEM) | 21E3-0042 | R210LC-7, R140LC-7, R160LC-3, R160LC-7, R180LC-7 | Direct OEM Equivalent |
| Hyundai (OEM) | 21E3-0042 | Other Hyundai -7 and -3 Series Excavators | May Fit Additional Models — Verify by Part Number |
Installation decomposition diagram
| Step | Action | Key Component | Specification / Torque Guideline |
|---|---|---|---|
| 1 | Safety Preparation | Hyundai Excavator & Electrical System | Park machine on level ground. Shut off engine, remove ignition key. Disconnect battery negative terminal. Allow all systems to cool. |
| 2 | Locate Sensor | Existing Sensor Position | Identify the revolution speed sensor location. Typically mounted on the flywheel housing, engine block, or hydraulic pump/motor assembly. Clean surrounding area thoroughly. |
| 3 | Electrical Disconnection | Harness Connector (Item 4) | Depress the locking tab and carefully unplug the wiring harness connector from the old sensor. Inspect terminals for corrosion, moisture, or damage. |
| 4 | Remove Old Sensor | Old Sensor (Flange Mount) | Remove the mounting bolt from the sensor flange. Carefully pull the old sensor straight out. Note the position and any shims or spacers present for air gap setting. |
| 5 | Inspect & Clean Mounting Surface | Mounting Port & Target Area | Clean the mounting surface with a lint-free cloth. Remove all old seal material and debris. Inspect the target gear teeth for damage or excessive wear. |
| 6 | Check & Set Air Gap | Sensor Tip & Target Gear | If applicable, install the correct shims or spacers. The air gap between sensor tip and gear teeth should match OEM specification (typically 0.5–1.5 mm). |
| 7 | Install New O-Ring | Rubber Seal (Item 3) | Fit the new lubricated O-ring onto the COGENG sensor. Lightly coat with clean engine oil or hydraulic oil. Do not use sealant or PTFE tape. |
| 8 | Sensor Installation | COGENG Sensor (Item 1) | Insert the sensor into the mounting hole carefully. Install the mounting bolt and tighten to OEM specification (typically 8–12 Nm). Do not over-torque. |
| 9 | Electrical Reconnection | Harness Connector | Firmly push the connector onto the sensor socket until the locking tab produces an audible click. Tug gently to confirm secure positive engagement. |
| 10 | Final Verification | Battery, Engine & Diagnostic Systems | Reconnect the battery. Start the engine and monitor the tachometer or diagnostic display for correct RPM/speed reading. Check for any active fault codes. |
Frequently Asked Questions
| FAQ Topic | Question | Answer |
|---|---|---|
| Model Compatibility | What Hyundai excavator models does 21E3-0042 fit? | This revolution speed sensor is a direct fit for Hyundai R210LC-7, R140LC-7, R160LC-3, R160LC-7, and R180LC-7 excavator models. It may also fit other Hyundai -7 and -3 series machines. Always verify the part number on your old sensor before ordering. |
| Sensor Function | What does the revolution speed sensor measure? | This sensor detects engine RPM, hydraulic pump speed, or swing motor speed depending on its mounting location. It generates a pulsed electrical signal proportional to rotational speed, which is sent to the machine's ECU or instrument panel for monitoring and control. |
| Sensor Type | Is this a magnetic pickup or Hall effect sensor? | This sensor is typically a Hall effect or inductive magnetic pickup type that detects the passing of gear teeth or a target wheel. It provides a reliable digital pulse signal for accurate speed measurement. |
| Air Gap Importance | Why is the air gap critical during installation? | The air gap (distance between sensor tip and target gear) directly affects signal strength. Too large a gap produces a weak or no signal. Too small a gap risks physical contact and sensor damage. Always verify the correct gap matches OEM specification. |
| Direct Replacement | Is the COGENG sensor plug-and-play? | Yes. The CG-21E3-0042 is manufactured to exact OEM electrical, mechanical, and signal output specifications. The connector is pre-configured with the correct pinout. No wiring modifications or ECU reprogramming is required. |
| Material & Build Quality | What materials are used in this sensor? | The sensor body is constructed from high-strength iron/steel for durability in harsh engine and hydraulic environments. The sealing element is oil and temperature-resistant rubber (Viton/Nitrile). COGENG is an ISO9001 certified manufacturer. |
| Troubleshooting | What if the speed reading is erratic or missing after installation? | Systematically check: 1) Harness connector is fully seated and clicked into place. 2) Correct air gap between sensor tip and target gear. 3) No bent or corroded pins in the connector. 4) Wiring harness continuity between sensor and ECU. 5) Target gear teeth are clean and undamaged. 6) Correct sensor variant for your specific machine. |
| Order & Logistics | What are the payment, packaging, and shipping details? | Payment Terms: T/T, Western Union, L/C, MoneyGram, D/A, D/P. MOQ: Acceptable trial order with no minimum quantity. Packing: PP bag inside, carton box outside. Shipping: By air, by sea, or by express (FedEx, UPS, DHL, TNT) from Guangdong, China. Supply Capacity: 500 PCS. |
