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Engine support
Technical Support

Maintenance intervals

Seriously conducted maintenance supports the long life of the engine. The VM diesel engines are very easy to maintain. Nevertheless, it is important to adhere to certain maintenance intervals (documents in German).

After-sales service
Phone +41 33 439 81 77

Wartung Dieselmotoren

Service form in case of engine repair

Does your engine not run properly? To ensure an efficient engine repair, please provide the companies involved with the necessary engine and machine information. We therefore make available the form below:
Spare parts
We offer a complete inventory of replacement parts with a high degree of availability. As the spare parts may vary due to vehicle-specific equipment, VM Motori provides a tool to find the correct spare part number by entering the engine serial number. Please call us for further information. We would be happy to assist you.

For spare part orders:
Phone +41 33 439 81 83

In this section we provide you instructions and up-to-date software for the VM Diagnostic Tool.

Please evaluate first with which Diagnostic Tool you work, to download the correct Software.

Diagnostic Tool Generation 1 + 2

Diagnostic Tool Generation 3

Download TeamViewer


For the Diagnostic Tool Installation with Windows 8, you can operating instruction from Windows 7.

Attention: Before the installation you have to do the following settings according to the video.

Attention! File must be unzipped after download and follow the installation instructions!

Type: zip
File size: 126 MB
Downloads: 185
Latest update: 17.06. 2021

!Attention: After downloading the file, please unzip and follow the installation instructions!

Type: zip
File size: 138 MB
Downloads: 298
Latest update: 10.05. 2019

Tips & Tricks
In this section we would like to offer you tips & tricks as well as to point out necessary steps to keep in mind during service and repair works.


The engine number is composed of an engine code and a 5-digit serial number. On the one hand it is designated on the identification plate, on the other hand it is punched on the crankcase.
Identifikation VM Motoren
Identifikation VM Motoren

How to identify VM engines?

We offer you an overview to easily identify the different VM engine types:

Standards and directives for performance evaluation

The engine performance values result according to different directives. Some manufacturers indicate the engine performance according to ECE R24, others according to ISO, SAE or 97/68/EWG.

The table below shows the evaluation of the different values. You see at a glance the auxiliaries running during the performance measurement. They partly have a considerable impact to the engine performance.

Standards and directives for engine performance evaluation

Exhaust system

After a maintenance or repair of VM EURO4 or EURO5 engines, you can carry out the following check to make sure that the intake throttle valve is connected accurately:
  • Start the engine and stop it again after a short time
  • The intake throttle valve is correctly connected when it closes immediately after switching off the engine and opens completely again right away.
The correct connections are represented in the following diagram:

Drosselklappe VM Motor 

Check the filters of the vacuum modulators

For EURO4 and EURO5 engines running under difficult conditions, we recommend to also check the filters of the vacuum modulators during the service carried out every 300 hours.

Clean the filters if necessary by using air pressure to blow out impurities. Pay attention to the safety instructions and wear safety glasses.

If the filters are wet or brittle, the complete modulators have to be replaced.


Cleaning of the particulate filters at EURO4 engines, series VM R750EU4

If an engine doesn't run regularly at operating temperature, this can cause plugging of the particulate filter. In this case, as it is generally known for EURO4 engines, the service regeneration has to be carried out with the VM diagnostic tool.

Furthermore it is very important to dismount the filter body previous to the service regeneration and to clean it as described in the engine instructions manual (in German) (with dry compressed air or with an electrical oven designed for the cleaning of particulate filters).

Maintenance of the particulate filter at EURO5 engines, series VM R750EU5, as well as stage 3B engines of the series R750IE4

The particulate filter service on EURO5 engines is completely different from EURO4 systems. The particulate filters have to be maintained under the following conditions:
  • every 4000 operating hours
  • in case of error code 242F
Manual for the maintenance of the particulate filter (in German)

Maintenance of the particulate filter at EURO6 engines, series VM R750EU6

The particulate filter service on VM Euro 6 engines is carried out in the same manner as for the Euro 5 engines.

Engine diagnosis

Motordiagnose Euro 6 A continuous recording of customer and machine data allows to react quickly whenever necessary. The VM diagnostic tool offers good possibilities to save engine data in a simple manner as so called "log files".

We would like to show you how to save these files efficiently for a possible later reuse.

Instructions of VM diagnostic tool "Saving engine data"
Electronics also simplify the diagnosis. Today, engine parameters can be supervised, failures displayed and various diagnosis tests can be carried out with specific developed software. This provides significant advantages. The diesel engine is nevertheless an aggregate with a lot of mechanical components. Therefore a systematic procedure at trouble shooting is very important:

Don't forget the basic principle of a diesel engine in spite of the electronics!

Fuel system

Installation of the injectors

Grease the injectors prior to mounting in order to grant an easy dismounting during the next service.


Apply Molykote P1500 grease on the injectors as indicated above (image on the left side). To ensure optimum lubrication, the grease has to come out on the injector seat on rocker arm cover after mounting (image on the right side).

What do the IMA codes on the injectors signify? Einspritzdüse Injektor

Each injector is branded with a different IMA code. In the engine control unit, this code serves as a correction value (for adjustment of tolerances on the injectors) in order to ensure an optimal injection quantity at the time of injection.

Pay attention to write the IMA code into the engine control unit using the VM diagnostic tool in case of the exchange of injectors or of the engine control unit.
Engine series IMA code Type part
EU6/IE4/ISE4/TE4 7 digits 543
EU5/IE3 7 digits 400
EU4 6 digits 286


Operation of the KSB at engines of the series D700/750 and HR

By means of the KSB (cold start aid), the injection timing is advanced in case of a cold engine. Therefore the ignition delay at low engine temperatures is compensated. A combustion with optimized exhaust emissions is consequently granted, also at cold engine temperatures.

The KSB is a control element, i.e. a thermal expansion element that brings the injection pump lever into the service position by means of current feed (engine at operating temperature). The KSB device is controlled respectively activated by a water temperature switch in the cylinder head. The movement of the KSB upon engine warm-up is gradual.

If the control element isn't fed with current and if the engine is cold, the lever is in "tight" position.

KSB setting and wiring

The KSB setting is described in the workshop manual, page 7-34, of the engine series D700/D754. The wiring is carried out according to this schema.

Changing the KSB connecting lid

In case of a leaky cold start aid, a gasket kit for the KSB is available. Please find herewith a reference guide how to change the KSB connecting lid (in German).


Shall your engine start easily also during Winter season? Then your battery needs some more attention in advance. If the battery tension breaks down during the start process under cold weather conditions, a failure may appear in the engine control unit at VM Common Rail engines. An insufficient battery charge or the consequent high tension lost at battery poles (oxidized battery poles) are often the cause.
  • The battery surface has to always stay dry and clean. Otherwise the battery gets discharged due to creepage current
  • Check the battery and the cable connections at regular intervals for its firmness. Retighten them if neccessary
The following checks apply additionally for starter batteries with vent plug:
  • Check the fluid level regularly. A water consumption is normal during a warm summer season, but it is recommended that the voltage setting potentiometer should be checked by an expert if consumption is noticeably high
  • In the event of a low fluid level of the battery, refill exclusively with distilled water (never acid!)

A proper environment of the battery is essential

Unclean poles cause creepage current and the starter battery looses energy. The engine gets discharged especially during short distance operation. Starting problems are the consequence, particularly in winter season.
Hydraulic tappets facilitate the maintenance significantly, as the valve clearance hasn't to be adjusted anymore. This fact reduces maintenance costs and guarantees optimum timing.

Hydraulic tappets come into operation in the following VM diesel engines:
R750 all engine types  
HR EURO 2 / EURO 3 all engine types  
D700 D703L, beginning from engine no. 28B 02700
  D703LT, beginning from engine no. 29B 02642
  D703LTS, beginning from engine no. 66B 01030
  D704L, beginning from engine no. 21B 03060
  D704LT, beginning from engine no. 22B 03029
  D706LT, beginning from engine no. 27B 01534
D700E all engine types  
D700E2 all engine types  
D700E3 all engine types  

If you carry out maintenance on engines with more than 3000 working hours, we recommend to replace all hydraulic tappets in case of dismounted cylinder heads.

Anti-freeze fluid in the cooling circuit

In cold season, we would like to point out that the engine coolant always has to consist of 50% water and 50% anti-freeze fluid.

Anti-freeze fluid is not only important at cold temperatures. It protects the cooling circuit and the engine also against rust and corrosion. Therefore it strictly has to be used all year round.

The used engine coolant has to correspond to standard ASTM D3306, type 1, and different cooling liquids should not be mixed!

Reset of „oil dilution calculation“ on following VM engines:
R750 series EU5, EU6, TE4, ISE4, IE4

On the above mentioned engines, whenever the engine oil has been changed, it is necessary to reset the function “oil dilution calculation”. If the reset will not be carried out, a failure appears on the engine control unit.

This function can be reset with the VM diagnostic tool but also with the accelerator pedal. On some vehicles, the accelerator pedal procedure is not feasible and the potentiometer accelerator can be used.

Instructions for engine oil change (page 34 of the workshop manual)

It is assumed that the personnel is familiar with industrial product servicing procedures. Furthermore, it is assumed that they have been trained in the recommended service procedures of VM Motori Products, including the use of mechanics’ common hand tools and the special VM Motori or recommended tools from other suppliers.

To submit a warranty claim, please use the official warranty form.

Download   official 
warranty form

Please note the following points:

Submission deadline for warranty claims

Please send us the complete warranty claim form 10 days after the date of repair to the listed e-mail address below.

What must be submitted?

  • Material: The warranty material must returned to us in any case for analysis (please always with a copy of the warranty claim form). 
  • Turbocharger: In case of damages of a turbocharger, you have to send in addition an oil sample.
  • Logfiles: For each damage on a Common Rail-engine you have to create Logfiles  and send them electronically with the warranty claim form (one Logfile at the time of the damage and the other one after the correction of the damage). 
  • Photos: So that the reason of the damages can be better assessed, please take some photos of the damage and send them to us.


Warranty claim form by e-mail warranty@hwag.com
Phone for questions: +41 33 439 81 96

Address for return delivery warranty parts:
Hans Wegmüller AG, Garantie, Pfauenweg 2-3, CH-3613 Steffisburg

For the VM-warranty conditions you can send an e-mail.


After Sales Service - Warranty
Phone +41 33 439 81 96

We offer you creative solutions in a flexible and dynamic manner. Let us know your requirements. We are prepared and will be delighted if you contact us.


Hans Wegmüller AG
Pfauenweg 2–3
CH-3613 Steffisburg

Phone +41 33 439 81 81
Fax +41 33 439 81 80
email hwag@hwag.com