| Parameter | Details |
|---|---|
| Product Name | Engine Coolant Temperature (Water Temp) Sensor / Switch |
| Part Number | 21EN-40100 (also 21EN40100) |
| Compatible Brands | Hyundai |
| Compatible Excavator Models | R60-7, R55-7, R220-5, R220-7, R225-7 |
| Sensor Type | NTC Thermistor (Coolant Temperature) / Temperature Switch |
| Material | Brass / Stainless Steel + Rubber Seal |
| Packing | PP bag inside, carton box outside |
| Payment Terms | Western Union, L/C, T/T, MoneyGram, D/A, D/P |
| MOQ | Acceptable trial order (1 piece accepted) |
| Shipping Mode | Air/Sea/Express (FedEx, UPS, DHL, TNT, etc.) |
| Place of Origin | Guangdong, China |
| Brand Name | COGENG |
| Certification | ISO9001 |
| Stock Status | ✅ In Stock |
| Warranty | 6 Months |
| Supply Capacity | 500 PCS |
The COGENG 21EN-40100 Water Temperature Sensor is a high-precision, direct OEM replacement sensor/switch designed for a wide range of Hyundai excavators, including the R60-7, R55-7, R220-5, R220-7, and R225-7 models. These popular excavators are used in construction, landscaping, utility work, and heavy infrastructure projects worldwide.
Depending on the specific application, this component functions as either a:
Coolant Temperature Sensor (NTC Thermistor): Provides continuous temperature readings to the ECU for fuel control, fan control, and emissions management.
Temperature Switch: Activates or deactivates circuits at a preset temperature (e.g., warning lights, fan engagement, cold start aid).
This sensor monitors engine coolant temperature—one of the most critical parameters for engine performance, fuel efficiency, and longevity.
Why Coolant Temperature Monitoring is Critical:
| Function | How Temperature Data is Used |
|---|---|
| Fuel Injection Timing | Adjusts timing based on engine temperature for optimal combustion |
| Cold Start Assistance | Enables glow plugs / intake heaters in cold weather |
| Cooling Fan Control | Engages the hydraulic or electric fan at high temperatures |
| Warning Systems | Triggers alarms and derates the engine if overheating occurs |
| Emissions Control | Optimizes combustion for reduced emissions |
| Dashboard Gauge | Displays accurate temperature to the operator |
| Engine Protection | Shuts down engine if critical temperature is exceeded |
Manufactured under ISO9001 certified processes, the COGENG 21EN-40100 features a brass/stainless steel housing, premium rubber O-ring, and a precision thermistor/switch element to ensure accurate readings across the full temperature range (-40°C to +150°C).
Why Choose COGENG 21EN-40100?
Wide Model Compatibility: Fits multiple Hyundai R-Series excavators.
Direct OEM Replacement: Plug-and-play for Hyundai 21EN-40100.
High Accuracy: Precisely calibrated to Hyundai ECU specifications.
Durable Construction: Brass/stainless steel housing withstands vibration and corrosion.
Leak-Proof: Premium O-ring pre-installed.
In Stock: Ready for immediate shipment with fast shipping.
| Component | Quantity | Description |
|---|---|---|
| Water Temperature Sensor/Switch | 1 | Complete assembly with pre-attached connector |
| Rubber O-ring / Sealing Ring | 1 | Pre-installed on threaded base |
| Protective Plastic Cap | 1 | For shipping protection only |
| Installation Quick Guide | 1 | Basic instructions |
Note: No additional hardware or sealant is required for installation.
This sensor is specifically designed for the following Hyundai R-Series excavators:
| Model | Engine | Typical Year Range | Sensor Type |
|---|---|---|---|
| Hyundai R55-7 | Yanmar / Hyundai | 2000–2010 | Temp Sensor / Switch |
| Hyundai R60-7 | Yanmar / Hyundai | 2000–2010 | Temp Sensor / Switch |
| Hyundai R220-5 | Hyundai / Cummins | 1995–2005 | Temp Sensor / Switch |
| Hyundai R220-7 | Hyundai / Cummins | 2000–2010 | Temp Sensor / Switch |
| Hyundai R225-7 | Hyundai / Cummins | 2000–2010 | Temp Sensor / Switch |
Additional compatible models (verify before purchase):
| Model | Compatibility |
|---|---|
| Hyundai R55-5 | ⚠️ Check connector type |
| Hyundai R60-5 | ⚠️ Check connector type |
| Hyundai R80-7 | ⚠️ Similar – verify |
| Hyundai R130-5 | ⚠️ Similar – verify |
| Hyundai R200-5 | ✅ Likely compatible |
| Hyundai R210-7 | ✅ Likely compatible |
| Hyundai R290-7 | ✅ Likely compatible |
⚠️ Important: The 21EN-40100 is used across multiple Hyundai R-Series models. Some applications use it as a temperature sensor (ECU input), while others use it as a temperature switch (warning light/fan control). Verify your old component's function before ordering.
| Model | Engine | Displacement | Configuration |
|---|---|---|---|
| R55-7 / R60-7 | Yanmar / Hyundai | 2.5L – 3.0L | 4-cylinder diesel |
| R220-5 | Hyundai / Cummins | 5.9L – 6.7L | 6-cylinder diesel |
| R220-7 | Hyundai / Cummins | 5.9L – 6.7L | 6-cylinder diesel |
| R225-7 | Hyundai / Cummins | 5.9L – 6.7L | 6-cylinder diesel |
Normal Coolant Temperature Ranges:
| Condition | Temperature | Action |
|---|---|---|
| Cold Start | 0-30°C (32-86°F) | Glow plugs active |
| Warmup | 30-70°C (86-158°F) | Normal operation |
| Normal Operating | 75-95°C (167-203°F) | Optimal fuel economy |
| High Temperature Warning | 100-105°C (212-221°F) | Check cooling system |
| Overheat / Derate | >105°C (>221°F) | Engine derates |
| Brand | Part Number | Notes |
|---|---|---|
| COGENG | 21EN-40100 (also 21EN40100) | Direct replacement |
| Hyundai (OEM) | 21EN-40100 | Original equipment |
| Hyundai (alternate) | 21EN-40100A | Updated version (verify) |
| Aftermarket | WT-21EN40100 | Similar |
Note: Always match your original sensor/switch part number. 21EN-40100 is the Hyundai OEM number for this component.
✅ Direct OEM replacement for:
Hyundai part number: 21EN-40100 / 21EN40100
✅ Designed For:
Hyundai R55-7 excavator
Hyundai R60-7 excavator
Hyundai R220-5 excavator
Hyundai R220-7 excavator
Hyundai R225-7 excavator
✅ Engine Compatibility:
Yanmar diesel engines (R55-7, R60-7)
Hyundai / Cummins diesel engines (R220-5, R220-7, R225-7)
✅ Electrical Specifications:
Connector: 1-pin or 2-pin (verify)
Operating Voltage: 5V DC (sensor) or 12V/24V (switch)
Output: Variable resistance (sensor) or on/off (switch)
✅ Mechanical Specifications:
Thread Size: 1/8-27 NPT or M10x1
Hex Size: 17mm, 19mm, or 22mm
Sealing: Rubber O-ring (pre-installed)
⚠️ Before purchasing, please verify:
| Check Item | Why It's Important |
|---|---|
| Machine Model | R55-7, R60-7, R220-5, R220-7, or R225-7 |
| Old Part Number | 21EN-40100 (or confirm) |
| Connector Type | 1-pin or 2-pin (photo recommended) |
| Function | Temperature SENSOR or TEMPERATURE SWITCH |
| Thread Size | 1/8-27 NPT or M10x1 |
❌ NOT Compatible With:
Hyundai R55-5, R60-5 (check connector type)
Hyundai R180, R200 (verify)
Hyundai R280, R290 (verify)
Non-Hyundai equipment (different ECU calibration)
Tools Required:
| Tool | Purpose |
|---|---|
| 17mm, 19mm, or 22mm wrench / socket | Remove and install sensor |
| Torque wrench (recommended) | Achieve 15–25 Nm spec |
| Clean rag | Wipe coolant spills |
| Flashlight | Locate sensor |
| Coolant (recommended) | Top up if needed |
Installation Tips:
⚠️ Engine must be cool – hot coolant can cause severe burns.
🧹 Clean mounting surface – debris can prevent proper sealing.
💧 Apply coolant to O-ring – helps seating and prevents twisting.
🔧 Do NOT overtighten – brass housing can crack at >30 Nm.
🚫 Never use PTFE tape – can clog coolant passages.
🔌 Listen for "click" – confirms connector is fully seated.
🔍 Check for leaks after engine reaches operating temperature.
Q1: What are the symptoms of a failing water temperature sensor/switch on a Hyundai excavator?
A: Common symptoms include:
Check Engine Light (CEL) with error codes.
Temperature gauge reads 0°C or pegged at maximum.
Engine derates (reduced power) due to incorrect ECU readings.
Hard starting in cold weather (no cold-start assist).
Cooling fan runs constantly or never runs.
Poor fuel economy.
Engine overheating without warning.
Warning light stays on or never illuminates (switch type).
Q2: Is this a genuine Hyundai OEM part?
A: No. COGENG is an aftermarket manufacturer (ISO9001) . Our parts are built to OEM specifications, offering the same fit and function at a reduced cost.
Q3: Will this sensor fit my Hyundai R60-7?
A: Yes – the R60-7 is one of the primary compatible models.
Q4: Will this sensor fit my Hyundai R55-7?
A: Yes – the R55-7 is one of the primary compatible models.
Q5: Will this sensor fit my Hyundai R220-5?
A: Yes – the R220-5 is one of the primary compatible models.
Q6: Will this sensor fit my Hyundai R225-7?
A: Yes – the R225-7 is one of the primary compatible models.
Q7: Is this a temperature sensor or a temperature switch?
A: The 21EN-40100 can function as either, depending on the application:
Temperature SENSOR: Provides continuous variable readings to the ECU.
Temperature SWITCH: Turns on/off at a preset temperature (warning light, fan control).
Check your old component's function and connector type before ordering.
Q8: What is the correct torque for this sensor?
A: 15–25 Nm (11–18 ft-lbs) . Do not overtighten – the brass housing can crack.
Q9: Can I install this sensor myself?
A: Yes, with basic mechanical skills (15–20 minutes). If unsure, professional installation is recommended.
Q10: Is this sensor in stock for immediate shipping?
A: Yes – COGENG maintains stock of 500+ units. Orders ship within 24–48 hours.
Q11: How long does shipping take?
A:
Express (DHL/FedEx/UPS/TNT): 3–7 business days worldwide.
Air freight: 7–12 days.
Sea freight: 20–40 days.
Q12: How do I place a trial order?
A: Contact your COGENG distributor. MOQ is 1 piece.
Q13: What is the warranty?
A: COGENG provides a 6-month warranty against manufacturing defects.
| Code | Description | Likely Issue |
|---|---|---|
| 110-03 | Engine Coolant Temp Sensor – Voltage High | Sensor open circuit / disconnected |
| 110-04 | Engine Coolant Temp Sensor – Voltage Low | Sensor shorted / internal failure |
| 110-08 | Engine Coolant Temp Sensor – Abnormal Frequency | Wiring interference / poor connection |
| PID 110 | Coolant Temperature – Out of Range | Sensor reading unrealistic |
| SPN 110 | Engine Coolant Temperature (J1939) | Sensor or wiring failure |
If codes persist after sensor replacement, check the wiring harness for damage.
| Parameter | Value |
|---|---|
| Sensor Type | NTC Thermistor or Temperature Switch |
| Temperature Range | -40°C to +150°C |
| Resistance @ 25°C (77°F) (Sensor) | ~10,000 Ω |
| Resistance @ 80°C (176°F) (Sensor) | ~2,000 Ω |
| Resistance @ 100°C (212°F) (Sensor) | ~1,000 Ω |
| Switch Activation Temp (if applicable) | 95°C – 105°C (verify) |
| Connector Type | 1-pin or 2-pin (verify) |
| Thread Size | 1/8-27 NPT or M10x1 |
| Hex Size | 17mm / 19mm / 22mm |
| Housing Material | Brass / Stainless Steel |
| Seal Material | Nitrile rubber (NBR) |
| Operating Voltage | 5V DC (sensor) or 12V/24V (switch) |
| Response Time | <5 seconds |
| ISO Standard | ISO9001:2015 |
| Country of Origin | China (Guangdong) |
| HS Code | 90259000 |
| Weight | Approx. 40g |
| Condition | Temperature | Gauge Reading | Action |
|---|---|---|---|
| Cold Start | 0-30°C (32-86°F) | Cold | Glow plugs active |
| Warmup | 30-70°C (86-158°F) | Rising | Normal |
| Normal Operating | 75-95°C (167-203°F) | Mid-range | Normal |
| High Temp Warning | 100-105°C (212-221°F) | Red zone | Check cooling system |
| Overheat / Derate | >105°C (>221°F) | Red zone | Engine derates |
To ensure we ship the correct sensor/switch, please provide:
Machine Model: R55-7 / R60-7 / R220-5 / R220-7 / R225-7
Machine Serial Number: (helps confirm configuration)
Old Part Number: 21EN-40100 (or confirm)
Function: Temperature Sensor or Temperature Switch
Photo of Old Sensor/Switch: (recommended – helps identify connector and thread type)
✅ In Stock – Ready to Ship.
✅ MOQ 1 piece accepted for trial orders.
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