Diesel Pump EDC Testing & Repair

Bosch VP44 diesel pump EDC

Having problems with a diesel non-start fault, pump control fault or diesel pump EDC fault?

Freestorm tests and repairs Bosch VP44 diesel pump EDC control units, also known as PSG5 pump control units, fitted to many diesel cars and vans.

If your vehicle cranks but will not start, starts and cuts out, or diagnostics show diesel pump control fault codes, send us your vehicle details and we’ll help check the best repair option.

  • VP44 EDC Repair

    Testing and repair for common Bosch VP44 diesel pump electronic control unit faults

  • Non-Start Fault Help

    Support for common diesel pump EDC faults that can stop the engine from starting

  • Repair First

    A repair may save the cost of replacing the full diesel pump

  • 5-10 Working Days

    Typical turnaround from receipt of the unit

  • Customer Support

    We help with part numbers, booking, delivery and updates

What is a Bosch VP44 diesel pump EDC?

The Bosch VP44 is a diesel injection pump used on many older diesel cars and vans. It has an electronic control unit fitted to the pump, often called the EDC, PSG5 or diesel pump control unit.

The mechanical side of the pump moves and delivers fuel. The EDC control unit helps control pump operation electronically.

When the EDC fails, the engine may not start, may cut out, or may store diesel pump control fault codes. In many cases, the issue is with the electronic control unit on the pump rather than the full mechanical pump.

Why Bosch VP44 diesel pump faults should be checked

A faulty VP44 diesel pump EDC can stop the engine from starting. The vehicle may crank normally, but the pump may not run correctly because the electronic control unit has failed.

In some cases, the fault may appear as an intermittent starting issue at first. Later, the vehicle may fail to start completely.

Diesel pump faults can also be confusing because similar symptoms can come from other issues, such as fuel supply problems, air in the fuel system, wiring faults, immobiliser issues, crank sensor faults, relay faults or battery voltage problems.

That is why it is better to check the fault properly before replacing the full diesel pump

Repair vs Replacement

Remanufacturing is a structured industrial process that returns used parts (cores) to reliable working condition through inspection, replacement of worn parts, rebuilding and testing.


Repair your own VP44 EDC unit

Best when:

The original Bosch VP44 diesel pump EDC control unit can be tested and repaired.

Benefits:

  • Keeps the original pump control unit from the vehicle
  • Can be cheaper than replacing the full diesel pump
  • May avoid unnecessary replacement of the mechanical pump
  • May avoid issues with used pump units
  • Good option when the fault is inside the EDC control unit
  • Typical turnaround: around 5-10 working days from receipt
Book Repair

Replacement diesel pump

Best when:

The pump is mechanically damaged, badly contaminated, heavily corroded, physically broken or not suitable for repair

Benefits:

  • Full diesel pump replacement can be expensive
  • Used pumps may already have electronic or mechanical wear
  • Replacement may need setup or coding depending on the vehicle
  • A replacement will not fix the issue if the real fault is wiring, fuel supply, immobiliser, relay, battery voltage or another engine management fault
  • The fuel system should still be checked before and after fitting
Ask us before replacing

In many cases, checking the original Bosch VP44 EDC unit is the best first step. If the unit is too damaged to repair, we’ll let you know.

Common Bosch VP44 diesel pump symptoms

Bosch VP44 EDC faults usually affect starting and pump control. The fault may be intermittent at first or may cause a complete non-start.

Non-start / no start

The engine cranks but will not start

Starts then cuts out

The engine may start briefly and then stop again

Intermittent starting fault

The vehicle may start sometimes and fail to start at other times

Engine cuts out

The vehicle may cut out while running and then refuse to restart

Diesel pump fault codes

Diagnostics may show pump control, fuel quantity, timing or communication-related faults

No communication with pump EDC

Diagnostic equipment may not communicate correctly with the diesel pump control unit

Engine warning light on

The engine management light may appear with diesel pump-related fault codes

Poor running before failure

Some vehicles may run badly, hesitate or lose power before the pump EDC fails completely

Fault returns after clearing

Pump-related fault codes may clear for a short time but return when the vehicle is started or driven.

Common faults – VAG examples

Fault codes depend on the vehicle, engine and diagnostic tool. These are common examples only. They should not be used as a final diagnosis without testing.

00550 – Start of Injection Regulation

Can appear with VP44 pump timing or pump control faults

01268 – Quantity Adjuster Fault

Can point to fuel quantity control problems inside the diesel pump control system

01318 – Control Module for Injection Pump

May indicate a communication or control fault with the diesel pump control unit

89 – Injection Begin Error

May appear on some diagnostic tools as an injection timing or injection begin fault

Common Faults – Vauxhall / Opel examples

Fault codes depend on the vehicle, engine and diagnostic tool. These are common examples only. They should not be used as a final diagnosis without testing.

P1220 – Injection Timing Control Faul

Often linked to diesel pump timing or control faults

P1335 – Injection Pump Control Module Fault

Can indicate a pump control module or pump timing issue

P1630 / P1631 – Injection Pump Control Module Faults

Commonly linked to VP44 pump EDC control unit problems

P1660 – Fuel Cut-Off Solenoid / Pump Control Fault

May point to pump control, wiring or internal EDC faults

P1600 – Control Module Fault

May be linked to control module or communication issues, depending on the vehicle and tool used

What to do before sending your Bosch VP44 diesel pump EDC

Before sending the unit, please collect as much information as you can. This helps us check the fault faster and avoid delays.

  • Vehicle make, model and year
  • Engine size and fuel type
  • Registration or VIN, if available
  • Diesel pump part number
  • EDC / PSG5 number, if visible
  • Photo of the pump label
  • Diagnostic fault codes or report
  • Description of the problem
  • Whether the vehicle cranks but will not start
  • Whether the fault is constant or intermittent
  • Whether the engine cuts out
  • Whether any pump, immobiliser, wiring or fuel system work has already been done
  • Whether a used pump has been fitted before

Will the diesel pump EDC need coding after repair?

This depends on the vehicle and the unit fitted. In many cases, repairing the original VP44 EDC control unit can make the refit simpler because the original unit stays with the vehicle. If a replacement pump or used pump is fitted instead, extra setup, coding or matching may be required depending on the vehicle.

Checked, repaired and returned

We check the details, review the fault information, confirm the next steps and keep you updated.

  • Vehicle and pump details checked
  • Fault codes and symptoms reviewed
  • EDC unit tested before repair is confirmed
  • Repair carried out
  • Support available after refitting

Typical turnaround

Typical repair time: 5-10 working days from receipt of unit.

Typical turnaround is approximately 5-10 working days from receipt of the unit.

This can depend on the fault, testing time, repair work required, parts availability and courier times. We’ll update you if extra time is needed.

How the Service Works

  1. Book your repair

    Fill in the booking form with your vehicle, pump part number and fault details

  2. Send us your unit

    We confirm what to send and provide delivery instructions. Pack the unit securely and include your booking details

  3. Testing & Repair

    Your diesel pump unit is tested and repaired. If repair is not suitable, we’ll advise you

  4. Return ready for refit

    Your unit is returned with repair notes and warranty information

Book Repair

Suitable for vehicles fitted with Bosch VP44 diesel pumps

This service is for selected vehicles fitted with Bosch VP44 diesel pump EDC / PSG5 control units.

  • Audi A4 / A6 / A8 2.5 TDI V6
  • BMW E46 320d / E39 520d
  • Ford Fiesta / Focus / Mondeo / Transit
  • Nissan Almera / Patrol / Terrano
  • Volkswagen Passat 2.5 TDI V6
  • Skoda Superb 2.5 TDI V6
  • Vauxhall / Opel Astra / Combo / Corsa / Frontera / Meriva / Omega / Signum / Vectra / Zafira
  • Rover 25 / 45
  • Dodge Ram 2500 / 3500
  • and more

Frequently asked questions

How long does Bosch VP44 diesel pump EDC repair take?

Typical turnaround is approximately 5-10 working days from receipt of the unit, depending on the fault and repair requirements.

Do you repair the whole diesel pump?

This service is for the Bosch VP44 diesel pump EDC / PSG5 electronic control unit. The mechanical side of the pump must be checked separately.

Can a VP44 EDC fault cause a no-start problem?

Yes. A common symptom is that the engine cranks but will not start.

Can you tell me if my diesel pump EDC is repairable before I send it?

We can often advise from the fault codes, symptoms, pump part number and photos, but final confirmation may require testing.

Is the repair guaranteed?

Warranty depends on the part type and repair carried out. We will confirm the applicable warranty before or after assessment.

What information should I provide?

Please send the vehicle make, model, year, engine size, registration/VIN if available, pump part number, fault codes and symptoms.

Does a non-start always mean the diesel pump EDC is faulty?

No. Non-start faults can also be caused by fuel supply, air in the system, wiring, immobiliser, relays, crank sensor, battery voltage or other engine management faults.

Will the diesel pump need coding after repair?

This depends on the vehicle. Repairing the original EDC unit can often make refitting simpler, but the vehicle should still be checked with diagnostics after installation.

Can I fit a used diesel pump instead?

Sometimes, but used pumps may have unknown wear, coding issues or the same EDC fault later. Testing the original unit is often the better first step.

What if the mechanical pump is damaged?

If the mechanical pump is worn, contaminated or damaged, EDC repair alone may not solve the fault. The mechanical pump and fuel system should be checked separately.

Need help with a diesel pump?

Send us your vehicle details, pump part number, fault codes or symptoms and we’ll help check whether diesel pump EDC testing and repair is the right option.