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Throttle Position Sensor 3857487 – Fits Volvo Penta & MerCruiser
- $55.77
- $55.77
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How to Match This Part
This aftermarket throttle position sensor (TPS) replaces Volvo Penta / OMC 3857487 and the matching MerCruiser / Mercury numbers in the cross-reference below (including 853678T and current 8M0221731). It mounts on the throttle body and reports throttle-shaft angle to the ECM so fuel delivery and spark timing stay coordinated on GM-based marine MPI engines.
Match this part in this order:
1. OEM number on the removed sensor — 3857487 (Volvo Penta / OMC) or MerCruiser 853678T / 8M0097035 / 8M0221731 (Sierra 18-7700 family)
2. Engine brand and application — Volvo Penta / OMC gasoline 4.3–8.2L, or MerCruiser MCM / MIE MPI models listed below (often ECM 555)
3. Physical form — two-hole flange mount, three-wire connector, and a D-shaped throttle-shaft drive with O-ring seal
Compare the flange holes, D-drive, and connector with the product images before ordering. This is not the MerCruiser 805226A1 (Sierra 18-7630) family or the 803148 Mag / Black Scorpion TPS — those are separate listings.
Part Number Cross-Reference
Use these verified numbers to confirm you have the correct throttle position sensor. Brand names and OEM numbers are for identification only.
| Type | Brand | Part Number | Notes |
|---|---|---|---|
| OEM | Volvo Penta / OMC | 3857487 | Primary reference (shared Volvo Penta / OMC number) |
| OEM | Mercury MerCruiser / Quicksilver | 853678T | Also catalogued as 853678 and 802623; superseded to 8M0221731 |
| OEM | Mercury MerCruiser / Quicksilver | 8M0221731 | Current number; supersedes 8M0097035 and 853678T |
| OEM | Indmar | 556103 | Interchange OEM number |
| OEM | Crusader | R020041 | Interchange OEM number |
| Aftermarket | Sierra Marine | 18-7700 | Direct cross-reference |
| Aftermarket | Mallory Marine | 9-33702 | Direct cross-reference |
| Aftermarket | CDI Electronics | E13-0006 | Direct cross-reference |
| Aftermarket | EMP | 1300-13600 | Direct cross-reference |
This is an aftermarket part manufactured by JLM Marine. It is not sold as a genuine Volvo Penta, OMC, Mercury, MerCruiser, Quicksilver, Indmar, or Crusader component.
Compatible Engine Models
Confirm brand, displacement, and the original sensor number before ordering. On Volvo Penta and OMC gasoline engines the identification plate is typically on the block or flywheel housing; on MerCruiser sterndrive and inboard engines it is on the block or near the flame-arrestor cover. MerCruiser owners can also cross-check diagrams at Mercury Parts Diagrams. Always match the OEM number and physical form of the sensor you remove.
| Brand | Engine Model | Notes |
|---|---|---|
| Volvo Penta | 4.3L, 5.0L, 5.7L, 8.1L, 8.2L gasoline | Replaces 3857487 |
| OMC Cobra | Gasoline sterndrive applications using 3857487 | Same OEM number as Volvo Penta |
| MerCruiser | MCM / MIE 4.3L MPI; 5.0L MPI | Replaces 853678T / 8M0221731 family |
| MerCruiser | MX 6.2L MPI with ECM 555; 350 Mag MPI | Replaces 853678T / 8M0221731 family |
| MerCruiser | Black Scorpion Tow Sports; 377 Scorpion Tow Sports | Replaces 853678T / 8M0221731 family |
| MerCruiser | 7.4L MPI (L29); MCM 496 Mag & HO | Replaces 853678T / 8M0221731 family |
| MerCruiser | MIE 8.1S & 8.1S HO | Replaces 853678T / 8M0221731 family |
Not for 2006-and-up drive-by-wire throttle systems or LT1 applications. If your stamped number is 805226A1 or 803148, use the listing that matches that number instead.
Technical Specifications
| Specification | Value |
|---|---|
| Part type | Throttle Position Sensor (TPS) |
| Primary OEM replaced | Volvo Penta / OMC 3857487 |
| Drive / seal | D-shaped throttle-shaft drive with O-ring seal |
| Connector | Three-wire / three-terminal sender |
| Mounting | Bolt-on throttle-body flange (two mounting holes) |
| Engine systems | GM-based marine MPI / multi-port injected sterndrive and inboard engines (not drive-by-wire) |
Installation Guide
- 1 Disconnect the battery negative cable and let the engine cool. Remove the flame arrestor if it blocks access to the throttle body.
- 2 Unplug the three-wire harness from the old sensor. Note connector routing so the new lead is not strained against the throttle linkage.
- 3 Remove the two mounting screws and lift the sensor off the throttle shaft. Compare old and new side by side: flange holes, D-shaped drive, and connector position must match.
- 4 Align the D-drive with the throttle shaft, seat the sensor fully against the throttle body, then fit the screws and tighten evenly to the torque in your engine service manual. Reuse the original screws unless they are corroded or damaged.
- 5 Reconnect the harness until it locks, refit the flame arrestor, and reconnect the battery. If your service manual specifies a TPS voltage check or idle reset, follow that procedure with a digital multimeter or the manufacturer diagnostic tool.
- 6 Start the engine, let it idle, and open and close the throttle slowly while checking for smooth response and no stored fault codes.
Note: Professional installation is recommended for EFI throttle-body sensors.
Troubleshooting & FAQ
Important Notes
- Match the OEM number and the physical form of your original sensor before ordering. A different connector or drive shape means a different part.
- Not for 2006-and-up drive-by-wire systems or LT1 applications. Not for MerCruiser 805226A1 or 803148 TPS families.
- This is an aftermarket part. Brand names and part numbers are for reference only.
- Professional installation is recommended for EFI throttle-body sensors.
Why Choose JLM MARINE?
- Precision Fit: Cross-referenced to Volvo Penta / OMC 3857487 and the MerCruiser 853678T / 8M0221731 (Sierra 18-7700) family for the MPI applications listed above.
- Quality Control: Each batch is inspected for dimensional consistency and workmanship.
- Direct from Manufacturer: Aftermarket marine sensors engineered for reliable throttle-position feedback on GM-based marine MPI systems.
We can ship to virtually any address in the world with free shipping available for most regions.
For our typical US and Canadian customers , our shipping timeframes are as follows:
- Amazon FBA: orders will be delivered within 1-5 business days after placing the order (during certain special periods such as major promotions, Christmas, etc., the delivery time of Amazon FBA may be affected).
- US warehouse shipment: orders will be delivered within 5 days after placing the order.
- China warehouse shipment: orders will be delivered about 12 days after placing the order.
When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.
Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.
Founded in 2002, JLM Marine has established itself as a dedicated manufacturer of high-quality marine parts, based in China. Our commitment to excellence in manufacturing has earned us the trust of top marine brands globally.
As a direct supplier, we bypass intermediaries, which allows us to offer competitive prices without compromising on quality. This approach not only supports cost-efficiency but also ensures that our customers receive the best value directly from the source.
We are excited to expand our reach through retail channels, bringing our expertise and commitment to quality directly to boat owners and enthusiasts worldwide.
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