# 3804955 Control Unit Core | Genuine Volvo Penta Part

## 🔧 Product Description

Core deposit for a control unit, in the Ignition and Control Systems group. It is the refundable charge raised against the old control unit when the exchange unit is bought, and it comes back once the worn control unit is returned. The line itself is an accounting entry rather than a part, so nothing ships against it on its own. Under Volvo Penta's core numbering the exchange unit it belongs to takes part number 3801955, which is the number to quote for the component itself. It is one of 5 control unit cores running through this block, and nothing published against them separates one from another, so order the number that matches the control unit actually coming off.

## ⚙️ Key Features

-   Core deposit line, not a control unit you can fit
-   Belongs with the exchange unit, part number 3801955
-   Refunded when the old control unit is returned
-   Not separable from the other control unit cores here, so order by part number
-   Ignition and Control Systems group

## 🔌 Function

As a line item it carries the refundable core charge on the exchange; the control unit itself reads the sensors, drives the injection, timing and protection functions, and holds the engine to the map it was programmed with.

## ⚠️ Common Signs of Failure

-   This is a deposit line and has nothing to fail in itself; the signs below are what normally condemns the control unit being exchanged
-   Engine that will not start or cuts out at random with no fuel or air fault to be found
-   Warning lamps and stored fault codes that come straight back after the sensors and wiring have been renewed
-   No communication with the diagnostic tool, or a unit that drops off the bus when it warms up
-   Erratic running, surging or the engine dropping into limp mode for no traceable reason

## 🛠️ Service Notes

-   The charge is refunded when the worn control unit is returned, so keep the old unit and send it back rather than scrapping it
-   Ordering this number on its own supplies no part - it goes on the order beside the exchange unit, part number 3801955
-   Prove the sensors, earths and connector pins before condemning the unit, and be aware the exchange unit normally needs programming to the vessel before the engine will run

## 📦 Condition

-   Refundable core deposit - not a physical part

## Details

- **Price:** 2200.0 AUD
- **Vendor:** Volvo Penta
- **Type:** Exchange & Reman Units
- **Tags:** Volvo Penta

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 2200.00 AUD | In stock |

## Images

- 3804955 Control Unit Core | Genuine Volvo Penta Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/3804955-control-unit-core-genuine-volvo-penta)
> Updated: 2026-10-07