The COGENG MC849577 is a premium direct OEM replacement revolution speed sensor specifically engineered for the Kobelco SK200-6 excavator. This critical engine component monitors engine RPM (crankshaft speed) and provides essential timing signals to the ECU for fuel injection control, engine protection, and tachometer display. Manufactured to meet or exceed original Kobelco specifications, this durable, plug-and-play sensor ensures reliable speed detection, accurate readings, and long service life in demanding construction and excavation applications.
PRODUCT IDENTIFICATION
| Parameter | Specification |
|---|---|
| Product Name | Revolution Speed Sensor |
| COGENG Part Number | MC849577 |
| OEM Equivalent | Kobelco MC849577 |
| Product Type | Magnetic Pickup / Inductive Speed Sensor |
| Sensor Type | Variable reluctance (magnetic) |
| Output Signal | AC voltage (frequency proportional to engine speed) |
| Application | Engine RPM monitoring / Crankshaft position |
| Compatible Model | Kobelco SK200-6 Excavator |
| Material | Iron + Rubber (seals: NBR) |
| Packing | PP bag inside, carton box outside |
| Place of Origin | Guangdong, China |
| Brand Name | COGENG |
| Certification | ISO9001 |
| Supply Capacity | 500 PCS |
| Brand | Part Number |
|---|---|
| COGENG | MC849577 |
| Kobelco | MC849577 |
| Interchange | MC849578, MC849579, MC849580, VH894101290A |
| Parameter | Specification |
|---|---|
| Model | Kobelco SK200-6 Excavator |
| Type | 20-ton Crawler Excavator |
| Series | Dash 6 |
| Engine | Hino J08E / Mitsubishi 6D16 |
| Displacement | 8.0L (Hino) / 8.2L (Mitsubishi) |
| Cylinders | 6 in-line |
| Engine Power | 110-120 kW (147-160 HP) |
| Operating Weight | 19,000 - 21,000 kg |
| Production Years | Approx. 2000-2007 |
| Engine Model | Displacement | Cylinders | Fuel System |
|---|---|---|---|
| Hino J08E | 8.0L | 6-cylinder | In-line pump / Electronic governor |
| Mitsubishi 6D16 | 8.2L | 6-cylinder | In-line pump / Electronic governor |
Note: Verify your engine model before ordering. The SK200-6 may have either Hino J08E or Mitsubishi 6D16 engine. Contact COGENG with your machine serial number for exact compatibility confirmation.
| Component | Function |
|---|---|
| Sensor Type | Variable reluctance (magnetic pickup) |
| Target | Flywheel ring gear teeth |
| Output | AC voltage sine wave (frequency = engine RPM × number of teeth) |
| ECU Use | Engine speed calculation, fuel injection timing, protection |
| Engine Speed (RPM) | Output Voltage (AC) | Frequency (Hz) |
|---|---|---|
| Cranking (200 RPM) | 0.5 - 1.5 V | Low frequency |
| Idle (800 RPM) | 2.0 - 4.0 V | Medium frequency |
| Working (1,500 RPM) | 4.0 - 8.0 V | Higher frequency |
| Rated (2,200 RPM) | 6.0 - 12.0 V | High frequency |
| Function | Description |
|---|---|
| Engine RPM Display | Provides signal to tachometer (dash display) |
| Fuel Injection Timing | ECU uses speed signal for timing calculation |
| Engine Protection | Over-speed detection and derate |
| Starting Control | Starting motor disengagement signal |
| Diagnostics | Speed sensor fault detection (DTC) |
| Parameter | Specification |
|---|---|
| Sensor Type | Variable reluctance (magnetic pickup) |
| Output Signal | AC voltage (sine wave) |
| Output Voltage (min) | 1.0 V AC @ 200 RPM |
| Output Voltage (typical) | 2-12 V AC (engine speed dependent) |
| Coil Resistance | 200 - 500 Ω @ 20°C |
| Inductance | 100 - 300 mH |
| Air Gap | 0.5 - 1.5 mm (0.020 - 0.060 in) |
| Connector Type | 2-pin Deutsch / AMP |
| Parameter | Specification |
|---|---|
| Housing Material | Zinc-plated steel / Stainless steel |
| Thread Size | M14 × 1.5 |
| Hex Size | 17 mm (11/16") or 19 mm (3/4") |
| Seal Material | NBR (oil resistant) |
| Weight | 0.06 - 0.10 kg (0.13 - 0.22 lbs) |
| Overall Length | 50-70 mm |
| Tip Material | Magnetic steel |
| Pin | Function | Signal Type |
|---|---|---|
| Pin 1 | Signal (+) | AC voltage (variable frequency) |
| Pin 2 | Signal (-) / Shield | Ground / Shield |
| Parameter | Rating |
|---|---|
| Operating Temperature | -40°C to +125°C (-40°F to +257°F) |
| Storage Temperature | -40°C to +125°C (-40°F to +257°F) |
| Ingress Protection | IP67 (connector mated) |
| Vibration Resistance | 15G @ 50-2000Hz |
| Shock Resistance | 50G |
| Media Compatibility | Engine oil, diesel fuel, coolant |
| Feature | Benefit |
|---|---|
| Precision magnetic coil | Accurate speed detection across RPM range |
| Oil-resistant housing | Withstands engine environment |
| Sealed connector | IP67 for wet/dusty conditions |
| OEM-spec air gap | Direct fit to SK200-6 engines |
| 100% factory tested | Every sensor individually tested |
| Plug-and-play | Direct replacement, no calibration required |
| Test | Method | Acceptance Criteria |
|---|---|---|
| Coil Resistance | 100% measurement | 200-500 Ω |
| Output Voltage | Test stand with target wheel | 1.0V min @ 200 RPM |
| Insulation Resistance | 500V DC | ≥100MΩ |
| Dielectric Strength | 500V AC/60s | No breakdown |
| Temperature Cycle | -40°C to +125°C | No degradation |
| Vibration Test | 15G @ 50-2000Hz | No intermittent output |
✅ ISO 9001:2015 – Quality Management System
✅ RoHS Compliant
✅ REACH Compliant
✅ Meets Kobelco OEM Specifications
| Symptom | Root Cause | COGENG Solution |
|---|---|---|
| Engine cranks but no start | No speed sensor signal (ECU needs RPM to start) | New sensor restores signal |
| Tachometer reads zero (engine running) | Speed sensor failure | New sensor restores tachometer |
| Engine runs rough / misfire | Erratic speed signal | New stable sensor output |
| Intermittent engine shutdown | Intermittent speed signal loss | New reliable sensor |
| Engine derate / reduced power | ECU not receiving proper speed signal | New sensor restores full power |
| Hard starting / long crank | Weak or missing speed signal | New sensor improves starting |
| Check engine light (DTC) | Speed sensor circuit failure | New 100% tested sensor |
| Engine overspeed (false) | Erratic signal causing false reading | New stable sensor |
| DTC | Description | Resolution |
|---|---|---|
| P0335 | Crankshaft position sensor circuit | Replace speed sensor |
| P0336 | Crankshaft position sensor range/performance | Replace speed sensor |
| P0337 | Crankshaft position sensor low input | Replace speed sensor |
| P0338 | Crankshaft position sensor high input | Replace speed sensor |
| P0339 | Crankshaft position sensor intermittent | Replace speed sensor |
| Tool | Purpose |
|---|---|
| 17mm or 19mm wrench | Remove/install sensor |
| Feeler gauge | Measure air gap (if adjustable) |
| Rags / paper towels | Clean area |
| Multimeter (optional) | Test sensor operation |
| Kobelco diagnostic tool | DTC clearing (recommended) |
| Step | Action | Critical Note |
|---|---|---|
| Preparation | ||
| 1 | Park SK200-6 on level surface, lower bucket | Safety first |
| 2 | Shut off engine, remove key | Lock-out/tag-out |
| 3 | Allow engine to cool | Prevent burns |
| 4 | Locate speed sensor on flywheel housing | Typically at rear of engine |
| Removal | ||
| 5 | Clean area around sensor | Prevent contamination |
| 6 | Disconnect electrical connector (2-pin) | Inspect pins for damage |
| 7 | Remove old sensor (17mm or 19mm wrench) | Note orientation |
| 8 | Clean threads in housing | Remove debris |
| Installation | ||
| 9 | Check sensor tip for damage | Should be clean, no metal debris |
| 10 | Install new sensor hand-tight | Do not cross-thread |
| 11 | Set air gap (if adjustable) | 0.5 - 1.5 mm (0.020 - 0.060 in) |
| 12 | Torque to specification | 15-25 Nm (11-18 ft-lbs) |
| 13 | Reconnect electrical connector | Ensure fully seated, click |
| Final | ||
| 14 | Start engine, check for leaks | Inspect around threads |
| 15 | Verify tachometer operation | Should read RPM |
| 16 | Connect Kobelco diagnostic tool | Clear DTCs |
| 17 | Test machine operation | Verify normal function |
Compatible Equipment
This sensor is specifically designed for the Kobelco SK200-6 hydraulic excavator and its variants, which are powered by the Mitsubishi 6D34-T series diesel engine. In addition to the primary application, the MC849577 sensor fits multiple models across the Kobelco SK -6 and -8 generations that share this engine and sensor architecture. Compatible machines include:
Kobelco SK200-6 / SK200-6E – The primary and most common application
Kobelco SK200-8 – (may share this sensor depending on engine variant and production date)
Kobelco SK120-6, SK130-6, SK150-6 – Smaller models in the -6 series using the same engine family
Kobelco SK210-6, SK220-6, SK230-6, SK250-6 – Larger -6 series excavators with compatible engine platforms
Additional Applications: This sensor may also fit certain Mitsubishi-powered industrial generators, pumps, compressors, and other construction equipment where the same OEM sensor part number is specified
Important Verification: The MC849577 is specific to the Mitsubishi 6D34 engine series as configured in Kobelco excavators. Always verify the OEM part number stamped on your old sensor body or listed in your machine's illustrated parts catalog before ordering.
Installation Procedure
Installation is performed with the engine switched off, the starter key removed, and the engine allowed to cool. The sensor's air gap setting is the single most critical factor for a successful installation.
Step 1 – Locate the Sensor Mounting Port
On the Kobelco SK200-6 with the 6D34-T engine, the speed sensor is typically threaded into the engine's flywheel bell housing, positioned perpendicular to the starter ring gear teeth. Access may require opening the engine compartment side door and working from above or alongside the engine block.
Step 2 – Disconnect and Remove the Old Sensor
Trace the sensor wire to its electrical connector and unplug it by pressing the locking tab. Do not pull on the wire harness itself. Loosen the external lock nut, then unscrew the sensor body completely from the threaded port. Inspect the tip of the removed sensor for signs of physical contact with the ring gear, which indicates excessive wear or incorrect gapping.
Step 3 – Clean the Threaded Bore
Use a clean, lint-free rag to wipe any oil, dirt, or metallic debris from the sensor port threads and sealing surface. Inspect the ring gear teeth through the port using a flashlight, if visible. The teeth should be intact and free of excessive wear, rust, or build-up that could interfere with the magnetic signal.
Step 4 – Install the New Sensor and Set the Air Gap
Carefully hand-thread the COGENG MC849577 sensor into the bore until the sensor tip gently makes contact with a tooth of the ring gear. From this point of light contact, rotate the sensor counterclockwise (back out) by exactly ½ to ¾ of a turn. This rotation creates an air gap of approximately 0.5 mm to 0.8 mm, which is optimal for a clean, strong signal on this engine platform.
Step 5 – Secure the Sensor
While holding the sensor body firmly in position to prevent it from rotating and altering the set gap, tighten the lock nut securely against the mounting boss. A backup wrench on the sensor hex collar will help maintain the correct position.
Step 6 – Electrical Connection and Routing
Reconnect the wiring harness plug, ensuring the connector clicks fully into place. Route the sensor wire along the factory path, securing it with cable ties away from the exhaust manifold, turbocharger, and any moving linkages or fan belts.
Step 7 – Operational Test
Start the engine and observe the tachometer. The needle should rise smoothly and hold steady at any constant engine speed without jumping, dropping out, or flickering. If the tachometer reading is erratic or absent, switch off the engine and recheck the air gap and connector seating.
Q: What warning signs indicate a failing powershift harness?
A: Look for intermittent loss of drive, the transmission suddenly dropping into neutral, harsh or delayed gear engagement, frequent blowing of the transmission control fuse, and diagnostic codes pointing to solenoid circuit faults or speed sensor signal loss. In many cases, the root cause is wiring fatigue or chafing deep within the harness, not a failed solenoid itself.
Q: How do I confirm my JCB has the correct 4-speed powershift transmission for this harness?
A: Visually check the gear shift pattern; a 4-speed powershift will typically show positions 1 through 4, Reverse, and Neutral. Locate the transmission solenoid pack – it will have a multi-pin electrical connector. If you are unsure, provide your machine's full model designation and serial number to your COGENG dealer for exact verification.
Q: After installing the new harness, the engine will not crank. Is this related?
A: Yes. JCB backhoe loaders with powershift transmissions typically include a neutral start safety circuit. The starter relay coil is grounded or powered through the gear selector harness only when Neutral is selected. A misconnected or faulty harness can break this circuit, preventing cranking even though the battery and starter are in good condition.
Q: The new connector shell looks different from the original, but the pin count is the same. Will it work?
A: In many cases, yes. Aftermarket suppliers sometimes use an updated or alternative connector mold that is functionally identical. The critical factors are the pin count, the internal keyway orientation (to prevent mis-insertion), and the wire gauge. If the connector latches securely and the keyway aligns, it is likely correct. If it does not click home without force, stop and contact technical support with photos for guidance.
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