37840-R70-A01 Honda TDC Sensor | Genuine Used Part

🔧 Product Description

Genuine Honda V6 Top Dead Centre and Crankshaft Position Sensor - Part Number: 37840-R70-A01

A genuine used Honda Marine TDC and crankshaft-position sensor for selected BF175D, BF200D, BF225D and BF250D V6 four-stroke outboards.

The sensor detects the rotational position and speed of the crankshaft. The engine control module uses this signal to synchronise fuel injection, ignition timing and engine-speed calculations.

⚙️ Key Features

• Genuine used Honda Marine TDC sensor
• Correct OEM part number 37840-R70-A01
• Used on selected Honda V6 D-series outboards
• Provides crankshaft position and speed information
• Critical input for ignition and fuel-injection synchronisation

🚤 Compatibility

Commonly used on

• Honda V6 electronic ignition and fuel-injection systems
• Timing-cover and crankshaft-position monitoring assemblies

Typically suits

• Engine models:
• Honda BF175D
• Honda BF200D
• Honda BF225D
• Honda BF250D
• Standard and counter-rotation model groups using sensor 37840-R70-A01
• HP Range: 175HP - 250HP
• Engine Type: Honda V6 EFI four-stroke outboard
• Year Range: Model and frame-serial dependent

🔌 Function

The sensor generates a timing signal as the crankshaft reluctor or timing rotor passes the sensor tip. Without a valid signal, the ECU may be unable to determine engine speed or piston position.

⚠️ Common Signs of Failure

• Engine cranks but will not start
• Ignition spark and injector pulse are absent
• Engine stalls suddenly when warm
• Tachometer signal drops out
• TDC or crankshaft-position diagnostic code is stored
• Sensor resistance is outside specification
• Wiring insulation is damaged near the timing cover
• Metal debris collects on the magnetic sensor tip

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 37840-R70-A01 current listed Honda TDC-sensor reference

OEM / Related Numbers

• 37840-R70-A01
• 37840R70A01
• 37840-R70
• Honda sensor assembly, TDC
• Related timing rotor, mounting bolt and engine wiring harness

Aftermarket / Verified Equivalents

• Recmar: REC37840-R70-A01 - TDC sensor
• Aftermarket direct-replacement sensor under 37840-R70-A01

📦 Condition

• Genuine used part
• Removed from running engine where applicable
• In good working condition unless otherwise stated