Category Archives: Mercedes-Benz

How to fit a clutch on a Mercedes Kompressor Coupe

Schaeffer Automotive Aftermarket (UK) provides a full replacement guide for the C180 1.8 Petrol, 2003 model using LuK parts.

The Mercedes C Class has been on our roads since 1993. In 2003, Mercedes introduced the C180Sports Coupe range and this has become a popular and desirable vehicle.

The car we’re featuring in this clinic is a 1.8 Supercharged 2003 model, which had covered over 140,000 miles and the customer had noticed a little clutch slip.

Recommended fitting time: 4 hours LuK parts fitted: 624324019; 415018710; 510003510; 411014810

When carrying out a visual inspection it was apparent that this is a straightforward job that most independent workshops can carry out.

For this repair, the workshop equipment we advise is a two-post ramp and a transmission jack. With the vehicle placed on the ramp, it is recommended that you disconnect the negative battery lead for safety. There is no work to be carried out from the top side of the vehicle, so raise the ramp and remove the engine and gearbox under shields. Disconnect the PAS pipe from the gearbox bell housing by removing the two TRX bolts.


Exhaust centre removal

Disconnect the gearbox speed sensor multiplug located on the underside of the gearbox before disconnecting the reverse light switch multiplug at the rear of the gearbox. You should then remove the gearbox earth strap and now disconnect and completely remove the exhaust oxygen sensor.


Disconnect the exhaust centre joint by removing the three bolts (these may be corroded) and then remove the exhaust front pipe support bracket. Now remove the rear gearbox mounting, before disconnecting the prop-shaft from the gearbox.


Remove the rubber cushion drive unit, noting the position and colour of the bolts and washers as they have different locations. Now disconnect the hydraulic clutch pipe; the easiest point for this is where the hydraulic pipe comes through the transmission tunnel on the O/S. Once disconnected, the pipe connection needs to be blanked to prevent the fluid leaking out.


Remove both parts of the gear linkage: part one is achieved by removing the plastic cover from the linkage housing and then removing the cable by releasing the ball joint. Part two of the process is completed by removing the retaining pin from the selector rod above the output flange and disconnecting.

At this point you should block/support the prop-shaft and linkages using the cross member to give clearance around the rear of the gearbox. Support the gearbox with a transmission jack and remove the ten bell housing TRX bolts; all bell housing bolts can be accessed from the underside, with the use of a long extension bar. Ease the gearbox back until it is clear of the clutch and then lower and remove. The gearbox may be tight on the dowels so you should ensure the dowels remain in the engine and not the bell housing.

End limit


With the gearbox removed, an initial inspection showed the clutch was at its end limit as the three little adjustor ring springs were fully extended. Remove the clutch assembly and test the dual mass flywheel (DMF) for play and rock – this information is available through Schaeffler’s Repxpert website, on-line catalogue and/or DMF Checkpoint App.

Remove the Concentric Slave Cylinder (CSC) from the bell housing, clean the bell housing and fit the new CSC. Clean the flywheel face to remove the “glaze”; for this we used an Emory cloth. It is now good practice to try the new clutch plate on the gearbox input shaft to ensure the splines are correct and to lubricate the clutch splines with a small amount of high melting point grease so we have an even smear and any excess is wiped off. Fit the new clutch assembly using the correct Clutch Alignment Tool and checking the clutch plate is the correct way round showing ‘Getriebe Seite’ (Gearbox Side) on the outer face – we advise installing the clutch assembly with a Self Adjusting Clutch (SAC) fitting tool.

Ensure the gearbox bell housing dowels and the separator plate are still located properly. Refit all parts in reverse order and torque to the manufacturer’s specification. When bleeding the clutch hydraulic system, connect a bleed bottle to the bleed nipple with a hose and open the bleed nipple. This system is gravity bled so you must ensure the clutch master cylinder does not run dry. Reconnect the battery lead and ensure all electrical systems work correctly, such as the radio, central locking etc. Once the car has been road tested and checked, the job is complete.

What is DSG clutch technology?

Since 2008, many new VAG models have been equipped with the new seven-speed dual clutch gearbox (DSG) with an LuK dry double clutch (2CT) system, or – since 2004 – a six-speed wet clutch version which also features an LuK dual mass flywheel (DMF). You will find the six-speed version mostly fitted to larger, high powered vehicles, such as the Passat CC, whilst the seven-speed is being fitted to the ever more popular range of smaller vehicles throughout the range, such as the Polo and Golf.

Best of both worlds
These high-tech state-of-the-art transmissions are designed to incorporate the best advantages of both automatic and manual gearboxes. Automatic transmissions are able to offer superb driving comfort thanks to an automated gear shift and uninterrupted traction, whilst manual transmissions are sporty, fun and economical. A twin clutch system therefore combines the comfort of an automatic with the agility of a manual, along with incredibly smooth and fast gearshifts.

Technically, a DSG is an automated shift gearbox featuring two gear sets which operate independently of each other, thereby enabling fully automatic gear change without traction interruption. There is no clutch pedal and the conventional gear lever has been replaced with a lever with integrated Tiptronic function.

The image below shows a cutaway shot of an LuK Dry Double Clutch

As gear changes are fully computer controlled, it is much more difficult for poor or aggressive drivers to cause damage or premature wear to the system, which should help to optimise the expected service life of the clutch and gearbox components. Like conventional singledisc clutches, the dry double clutch of the seven-speed DSG is also located in the gearbox housing.

There are no drag losses as it is not oilimmersed, increasing engine and fuel efficiency whilst also making repairs less complex. From a technician’s point of view, the gearbox and clutch electronics (mechatronics) are diagnosable, so the system can be read using suitable diagnostic equipment. A full system reset – which puts the mechatronics unit into ‘Learn Mode’ – is required after every clutch replacement, again a simple function as long as you are using the correct equipment.

Since the clutch fitted to the Volkswagen six-speed DSG is oil-immersed (known as a wet clutch) it tends to wear at a much slower rate than equivalent dry clutches. However, there is the possibility that the DMF could wear and require replacement, especially as this transmission has been fitted to Volkswagen Group vehicles for more than 10 years. Fortunately, in a twin clutch transmission – and for the Volkswagen Group DSG in particular – this can be a much simpler task than for a conventional system, as the clutch is not bolted directly to the DMF.

No special tooling or training should be required for experienced clutch mechanics to be able to manage a twin clutch DMF replacement, and as the original equipment manufacturer of the dual mass flywheel for the six-speed Volkswagen DSG, LuK is on hand to supply the replacement DMF unit to the aftermarket as required.

The LuK Dry Double Clutch in-situ

The LuK designed and manufactured seven-speed dry clutch system also features a DMF that is not directly bolted to the flywheel and is just as simple to replace when worn. LuK engineers have also been investigating the potential for a complete replacement twin clutch kit solution for the UK aftermarket.

A range of original equipment components, specific tools and bespoke training programmes have already been designed and developed, and LuK is currently assessing the size of the opportunity for independents to offer the owners of vehicles coming out of the warranty period a viable aftermarket option when it comes to buying a replacement twin-clutch.

Due to its success with the DSG, the Volkswagen Group has already announced that more than 40% of the cars they produce will be fitted with a dual clutch system by 2012, and this has not gone unnoticed in the automotive world. With the improved fuel economy and lowered emission levels it can help provide, many other vehicle manufacturers are now beginning to specify twin clutch transmission systems to help keep in line with ever more stringent Government legislation.

Vehicle producers that are currently using twin clutch systems, or who are developing new versions to use in their range include: Audi, Ford, Honda, Hyundai, Mercedes-Benz, Renault, Seat and Skoda. LuK, as ever, will be at the forefront of this rapidly growing market, thanks to its ongoing commitment to innovation, technology and quality.

The benefits of a dual clutch system

• Combines the ease of an automatic transmission with the responsiveness of a manual gearbox
• Similar to an automatic transmission, but with excellent fuel efficiency
• No power interruption during torque transfer
• Significant reduction in CO2 emissions

How to change a clutch on a Mercedes C Class

Introduced in 2000, the Mercedes C Class W203 is a proven contender for the competitive executive compact market and has sold over 80,000 vehicles in the UK, making the vehicle a perfect candidate for this clinic.

A clutch replacement on the Mercedes can be a little tricky but with guidance of the LuK ‘Clutch Clinic’, the whole process will become much easier. Nothing out of the ordinary is needed to complete the job, the only special tools required are a transmission jack and a long axle stand. A four-post ramp was used in this example however a two-post ramp may also be suitable.

For safety reasons its considered best practice to disconnect the battery earth lead before commencing work. The vehicle may be fitted with anti-theft wheel bolts, so make sure you have the key before you start.

Raise the vehicle and remove the small rear under-tray and the supporting bracket attached to the chassis. Unbolt and remove the exhaust mounting bracket (Fig 1) and remove the large clip (Fig 2) securing the exhaust assembly to the down pipe.

Fig 1

Fig 2

While supporting the exhaust, remove the supporting rubber mountings near the rear silencer and lower the whole system to the floor. Undo and remove the two central heat shields (pictured below) to provide access to the propshaft.

Undo the centre support bracket for the prop-shaft and remove the clips connecting the gear change mechanism (pictured below) to the bracket.

While supporting the gearbox, undo the large mounting (pictured below) and the large rubber support.

Unclip both the handbrake cable and the selector cable and stow them to one side. Mark the positions of the front and rear propshaft flanges (pictured below) and remove the nut and bolts attaching them.

Unbolt and remove the centre bearing support and carefully lower the prop-shaft assembly to the floor. Release the gearbox change mechanism from above the gearbox, secured by a small clip and a ball joint.

Unplug all the electrical connections from the gearbox and near the bell-housing. Disconnect the slave cylinder connection by releasing the small clip (pictured below) and pulling out the pipe.

Plug the pipe to prevent leakage and undo all of the bell-housing bolts with support before carefully lowering the gearbox to the floor.

With the clutch removed, check the dual mass flywheel (DMF) for signs of heat stress and evidence of grease loss. The DMF should also be tested for ‘freeplay’ and ‘rock’ between the primary and secondary masses (LuK tool number 400 0080 10 is specifically designed for this purpose on all LuK manufactured DMFs). Full instructions and tolerance data for all LuK DMFs are contained on a CD which comes with this special tool.

Splines maintenance

Clean the first motion shaft splines and any debris from the bell housing (especially important when a release bearing has failed). Remember, if the bearing or sleeve is made of plastic there is no need for lubrication. If both parts are metal, a high melting point grease should be used and not copper-based products.

Put a small dab of grease on the first motion shaft splines and make sure the new driven plate slides freely back and forth. This not only spreads the grease evenly but also makes sure you have the correct kit. Wipe any excess grease off the shaft and driven plate hub. Using a universal alignment tool and checking the driven plate is the correct way round (note “Getriebe Seite” is German for “Gearbox Side”) the clutch can be bolted to the flywheel evenly and sequentially.

Before fitting the gearbox make sure the locating dowels are in place and not damaged. Refit any that have become dislodged and refit the gearbox. Make sure the gearbox bell housing bolts are secured before lowering the jack. Refitting is the reverse of the removal.

How to change a clutch on a Volkswagen Crafter

Available in many model ranges, the Volkswagen Crafter is a rebadged Mercedes Sprinter but with a VW powertrain. This ‘clutch clinic’ from LuK takes a look at how easy a clutch replacement can be on the CR35TDI LWB variant.

Launched in 2006, the Volkswagen Crafter is becoming a more popular vehicle on the UK roads, so it’s likely you will see these applications coming through your workshop.

The clutch replacement is pretty straight forward with no special tools required for the repair. In this article we used a four-post ramp a long axle stand and a transmission jack.

First, disconnect the battery earth lead and raise the vehicle. Remove both gear link cables by popping them out of the linkage arms and stow to the side.

How to change a clutch on a Volkswagen Crafter

Remove the gearbox cross member support which is held in place by a four nut and bolt arrangement to the chassis and two bolts into the gearbox.

How to change a clutch on a Volkswagen Crafter

Mark the propshaft position and remove the centre support bearing bracket. Remove the bolts for the propshaft on the gearbox side and disconnect from the gearbox. Secure the propshaft to the side, as you do not need to remove it completely to lower the gearbox.

Remove the support bracket for the DPF which is attached to the exhaust and gearbox.

How to change a clutch on a Volkswagen Crafter
A wiring harness is also attached to the bracket which is held by one bolt; this will also need to be removed.

How to change a clutch on a Volkswagen Crafter

Remove the hydraulic pipe and, using a blanking plug, block the pipe so you do not lose any fluid. Cut the cable tie holding the oxygen sensor cable to the gearbox.

How to change a clutch on a Volkswagen Crafter

Remove the 13 bell housing bolts and put them in order of removal. As they are all different lengths this will make it easier when putting the gearbox back in place. Carefully lower the gearbox to the floor and remove the worn clutch.
Remove the worn clutch cover and clutch plate. In this example the dual mass flywheel (DMF) was also replaced with the clutch and bearing. In most cases, however, you have no need to replace the DMF as this can be checked whilst on the vehicle for signs of heat stress and evidence of grease loss. The DMF should also be tested for free play and rock between the primary and secondary masses. LuK tool number 400008010 is specifically designed for this purpose. Full instructions and DMF tolerances can be found by searching “DMF data sheet” at

Refitting the gearbox

Clean the first motion shaft splines and any debris from the bell housing (especially important when a release bearing has failed). Put a small dab of high melting point grease (not a copper-based product) on the first motion shaft splines and make sure the new driven plate slides freely back and forth. This not only spreads the grease evenly but also makes sure you have the correct kit. Wipe any excess grease off the shaft and driven plate hub. Using a universal alignment tool and checking the driven plate is the correct way round (note “Getriebe Seite” is German for “Gearbox Side”) the clutch can be bolted to the flywheel evenly and sequentially.

Before fitting the gearbox make sure the locating dowels are in place and not damaged. Refit any that have become dislodged and refit the gearbox. Make sure the gearbox bell housing bolts are secured before lowering the jack. Refitting is the reverse of the removal.

Winter coolant servicing – profit opportunities and tips

Contemporary coolants have become every bit as ‘vehicle specific’ as engine oil. There are now three very distinct technologies used as ‘original fill’ by vehicle manufacturers. These coolants all perform the same essential functions – i.e. prevent freezing and overheating, while simultaneously protecting engine and cooling system components against corrosion and erosion. But their chemical additive formulations  – also called ‘packages’ – are entirely different, one from another, and can’t be mixed or substituted.

It means that for technicians to protect warranties, vehicles presented for servicing must be re-filled or topped up with the exact type of OE coolant that went in on-line. And that makes winter servicing with manufacturer-approved coolants a significant profit opportunity; an opportunity that switched-on independent workshops should be quick to grasp.

The most recent research conducted for Comma’s Professional Partner Programme revealed that franchised dealers typically charge £120 – and more – for a coolant drain and refill. Yet with the latest coolant re-filling equipment, the job can be done professionally, using the correct, manufacturer-approved coolants, in under half an hour at a charge-out rate around half that figure. In fact, three vehicles an hour could easily be serviced, making this a viable ‘while you wait’ proposition with high returns. The equipment is readily available, easy to use, requires no special training, and eliminates the need for thermo recycling – i.e. running the engine hot and cold to bleed off air.

Coolant technologies – What’s the difference?

For the European passenger car and LCV market, the three types of coolant specified by vehicle manufacturers are:

1) Silicate based technology.

2) OAT (Organic Acid Technology) based technology.

3) The most recently developed technology, based on a combination of both Silicate and OAT, and known as Si-OAT.

Silicate products have a 2/3 year service life before replacement; OAT and Si-OAT products have a longer, 5 year service life.

BASF Glysantin® coolants are the original equipment (OE) fill to most European VMs. These are designated either G48® (Silicate) G30® (OAT) and G40® (Si-OAT). The last of these – G40® – was specially developed in collaboration with VAG Group, and is  manufacturer-approved for all VAG (Audi, Bentley, Bugatti, Lamborghini, SEAT, Skoda and Volkswagen) models from 2005 onwards, plus selected Mercedes Benz and Porsche models..

Finding the right coolant

Comma’s coolant application data covers the entire UK vehicle park, dating back over 30 years (visit the VRN look-up at with every one of the 7,000+ recommended applications being covered by a 100% guarantee of compatibility and quality.

Technicians’ tips

For best coolant practise, follow these guidelines……and don’t forget to inform your customer about what you have done, and why.

  • When the additive package is ‘spent’, replace all coolant to restore full protection.
  • Check the vehicle handbook and always fill with the correct, manufacturer-approved or OE compliant coolant.
  • Never mix coolant types – it cancels out their individual protective properties and could actually lead to mechanical damage.
  • Use only de-ionised/distilled water – never tap water – to dilute concentrated coolants.
  • Flush old or dirty systems with cleaner before re-filling.
  • Visually check the entire coolant system for leaks after re-filling.

Brush up your engine coolant knowledge by visiting the Comma online training academy at

Can one engine oil be used for all makes of vehicle?

Comma explains why you should beware the ‘one-product-fits-all’ trap.

Comma periodically issues ‘Tech Talk’ training and information bulletins to help workshop technicians stay abreast of the latest developments and applications in lubricants, coolants, brake fluids and maintenance chemicals.

A recent bulletin reflects on how the once common practice of relying on a single barrel of 10W-40 for use on virtually every vehicle service has had to yield to strict ‘selection by application’ disciplines dictated by modern exhaust after-treatment systems based around three-way catalytic converters (CATs) and diesel particulate filters (DPFs). Such systems are highly sensitive to unwanted sulphated ash, phosphorous and sulphur – so called SAPS – in exhaust gases. It’s a problem that was addressed by ACEA when it introduced the ‘C’ category of reduced or low SAPS oils.

A suitable fit?

Headlined ‘There’s more to oil than “C3”, the bulletin cautions against stocking a single product – in this case ACEA C3 low SAPS engine oil – for use on all vehicles. It says that even though an oil is legitimately coded C3, it is a mistake to assume that it will be a suitable fit for every vehicle requiring an ACEA C3 oil.

As Comma points out, VMs now demand something very much more ‘bespoke’, and have their own distinct formulations for the ACEA C3 oils they specify for their engines. It is also the case that ACEA C3 isn’t only used with 5W-30 grades – certain Alfa Romeo and Fiat engines require ACEA C3 as a 5W-40 grade.

To illustrate the point, the bulletin uses spider charts below to show how certain oil specifications of VW, GM and Mercedes Benz differ greatly, one from another, while still conforming to – and in some areas exceeding – the ACEA C3 performance levels. The bulletin draws the conclusion that, by itself “ACEA C3 doesn’t always match VM specification.”

ACEA C3 vs VW 504 00/VW 507 00
ACEA C3 vs Vauxhall (GM) dexos 2
engine oil
ACEA C3 vs Mercedes-Benz MB 229.51

Trustworthy application data

With VMs’ lubricant recommendations now widely written-in as warranty critical requirements, the safest way to ensure correct selection is to use an up-to-date and trustworthy application tool, such as Here, technicians will find complete ranges of Comma engine oils, antifreeze and coolants in which they can have total confidence, covered as they are by the brand’s unique 100% ‘Compatibility Guarantee’ and embracing all European vehicles dating back over 30 years.

Starters & alternators technical bulletins – Various models

On Jaguar XJ and XK models (1996-2003) when an alternator problem is diagnosed, some customers have experienced charging problems – even after the fitment of a replacement unit. This is due to the battery being fitted in the boot of the vehicle. Consequently the wiring connections in the boot, passenger foot-well or false bulkhead under the bonnet may have high resistance. These should be checked and cleaned thoroughly. The part number primarily affected is AEK2286.

If the replacement alternator is overcharging after fitment, the cause may be due to no signal to the ‘C’ terminal of the connector plug from the ECU.

If there is no signal to the ‘C’ terminal on the alternator from the ECU, the alternator will show an overcharge of approximately 15.7 Volts. Possible causes of this are a broken wire in the loom, connector pins in the plug being damaged or open too far to make a good connection, or there may be an ECU fault. Part numbers affected are: AEK3195, AEK3196 and AEG1066.

3. VAUXHALL VECTRA 2007 ON 1.9 CDTI DIESEL BOSCH ALTERNATOR PULLEY FAILURE (see example images above and below)
Check the clutch pulley on the alternator that has been removed from the vehicle. If the pulley is seized, spinning freely in both directions without the alternator turning, collapsed or is missing, this will indicate a vehicle fault which has caused failure of the alternator. Fitting the new alternator without rectifying the vehicle fault will result in premature failure of the replacement alternator. Check the belt tensioner for correct operation and ensure that the belt has been correctly routed. The part number affected by this very common issue is AEK3125.

Check for faulty seat modules on Mercedes applications from 2000 onwards. A flat battery can lead to an incorrect diagnosis and subsequent replacement alternators can be fitted with the flat battery problem persisting. Often the problem is later found to be an electrical drain caused by a faulty seat module. Part numbers affected are: AEC1752 and AEG1142.

Technical help from Autoelectro
Autoelectro’s website ‘catalogue’ section lists specific technical information for many applications. All you have to do is click on the red ‘i’ that accompanies the product specifications.

Diagnosing a tricky MOT failure

When an older model Mercedes failed the MOT test on excessive emissions, the resulting trouble code proved less than straightforward in its attempt to explain the cause of the fault.

Steve Carter is a training specialist who heads up the team at Train4Auto – the sole UK and Ireland training provider for eXponentia.

A 1996 Mercedes E36 AMG was brought into the workshop after it failed its MOT. Apart from a few minor niggles, its main failure was that the emissions (both CO and HC) were a bit high. As a result of these two readings being excessive, it was also obvious that the Lambda was wrong as well.

The car appeared to drive well and was not suffering any major misfire and a 10 minute inspection of the engine bay did not reveal anything untoward. It was now time to see if there were any fault codes stored in the vehicle’s engine management ECM.

Fault code read
The system fitted to the vehicle was a Bosch Motronic M 3.4.2 and, although this vehicle is over 14 years old, the on-board diagnostic system seemed quite advanced for its years. The fault code retrieved was somewhat convoluted, reading: “Dwell angle end of control stop reached”.

Having established our fault code, it was now necessary to drill down further to understand the code definition. The engine management system on this particular vehicle, given its age, controls both fuelling and ignition in one.

So the dwell angle, or the amount of time the coils are being charged under the control of the engine ECM, had reached its limits and the engine ECM could not increase this time any further. This engine management system utilises three double-ended coils which are mounted directly between the camshafts, leaving very limited access for testing the secondary side of the coils. Instead, we focused on the primary side of the coils.

As you can see in Fig 1, there was a textbook primary wave pattern on two of the coils. Just prior to the firing line you can see the current limiting hump, indicating that the coil had become fully charged, and that the engine ECM had stopped charging this particular coil.

Fig 1: Two of the coils in the Mercedes were perfect,
as can be seen in this textbook coil primary trace.

 In Fig 2, the circumstances are far different. You can see straight away that there is no current limiting hump; in fact, 2ms into the coil charging time, the engine ECM stopped charging this coil, or what was more likely happening was that the insulation on this coil was breaking down.

Fig 2: One of the coils in the Mercedes was obviously faulty –
the result of a short to earth through the coil insulation.

Replacing the coil
The breakdown of the coil insulation created an earth path, and prevented this one coil from charging properly. Also note that the burn time was only half the time of the other two coils, and that there are no coil oscillations, therefore indicating a discharged coil. The faulty coil was replaced, the code was cleared and the emissions returned to normal.

Although this particular fault was on a 15 year old Mercedes, I’m sure many other vehicles will be suffering similar faults. However, we expect that the engine management system can recognise these faults and then give a text description that we can actually comprehend and then work with.

As cars get ever more complicated, it wouldn’t be a surprise to see the text description of the fault code following the same pattern.

How to improve your KTS diagnostics capabilities. Part 1: Selecting the correct vehicle

KTS diagnotics made ‘ESI’ from Robert Bosch.

Over the next 12 months Bosch will be running a series of technical articles, focused on how to get the best out of its ESI[tronic] 2.0 software, which is used in conjunction with the KTS range of diagnostic tools for vehicle fault diagnosis and service function procedures. Because of the vast range of features available through the software, Bosch’s technical team will be breaking things down into bite-sized chunks, starting at a beginner level and progressing through to more advanced functions.

ESI[tronic] 2.0 is the windows PC based diagnostic software platform that replaced the original classic software version in 2012.

This update gave us huge improvements in the ease of use with greater speed, efficiency and functionality. The ESI 2.0 software is used in conjunction with KTS 5xx series of VCI (Vehicle Communication Interface) hardware such as KTS 540 or 570 that will connect wirelessly to your PC device.

KTS diagnotics made ‘ESI’ For the first instalment in this series we’re going to show you some of the different ways available to select the correct vehicle that you want to work on in the ESI[tronic] software. Some readers may find this topic a bit basic but it’s important to remember that this is a crucial first step to ensure accurate results. If you need to perform any task on the vehicle which requires a serial diagnosis interaction with the Bosch tool, or any technical data or maintenance info look-up, it’s essential for the tool to give you information that you can trust.

Every vehicle listing in ESI[tronic] has an identifier code called an ‘RB key’ – this is unique to Bosch and typically consists of two or three letters and up to four numbers, for instance a 2014 Mercedes E220 BlueTec diesel has an RB key of ‘MB5743’ and a 2011 Vauxhall Astra 1.6i petrol is ‘VAU815’. As we cover more than 180 brands with many models you can imagine that there are quite a lot of RB keys to choose from.

Once you’ve selected a vehicle you then have access to the ‘Vehicle Info’, ‘Diagnosis’, ‘Troubleshooting’, ‘Maintenance’, ‘Circuit Diagrams’ (depending on your subscription level) and ‘Equipment’ (parts) tabs that will guide the user through all of the relevant functions and data that we have for that vehicle. If the wrong vehicle is selected by mistake and the diagnostic ECU system that you need is not fully identified, then some diagnostic functions may not work properly.

Warning message
In this case you’ll see a ‘Basic Program’ warning message on screen and the possible functions available may be reduced. If you continue with this you may see unknown DTC’s or Actual Values that are not accurate or even supported. Also the service related information and technical data could be wrong, which is not going to help any technician to do their job well. Our automotive technical hotline team will often ask callers which RB key they have selected so that they can look at the same information on their computer and understand the problem to help find a solution.

The first few ways of selecting a vehicle can be done before connecting the KTS VCI to the car. This is especially useful if you do not know where the 16 pin OBD connector is, as once you have chosen a vehicle you can select the ‘Diagnosis’ tab and click on the ‘diagnosis socket’ soft key which will open up a help file new window containing detailed descriptions and diagrams of the OBD connector type, location on the vehicle and individual pin assignments, if needed.

KTS diagnotics made ‘ESI’

KTS diagnotics made ‘ESI’

One point to note here is that sometimes the OBD socket location is only shown for a LHD vehicle, so for RHD the connector may be on the other side to that shown in the file.

On the second row of tabs, the first option to select a vehicle is ‘By Description’. Here you will use the drop down boxes to choose the Country (can be useful for imported vehicles), Vehicle Type (Car), Drive type (fuel type, hybrid or electric), Make, Model Series, Type and Engine Code. Depending on the model, this way can take a little longer but you don’t have to select an option in every field. Of course the more detail that is given at this stage will ultimately help to reduce the number of RB keys to choose from.

Correct information

When you think about how many different variations there are of a VW golf, for example, details such as engine code, year of manufacture, body style (saloon or estate) and kW (engine power output) will help you to choose the exact vehicle to get the right ECU diagnosis systems and information.

Going back to the example of the aforementioned Astra, if I select ‘Gasoline/Vauxhall/Astra [J] 2009on’ and click ‘search’ I’m then presented with a choice of nine RB keys, however just one more selection of the engine code (A16XER) brings this choice to just one RB key. Once your desired vehicle selection is highlighted in blue you can carry on with the job by selecting one of the main tabs across the top.

KTS diagnotics made ‘ESI’

If you already know the correct RB key of the vehicle in question (it may be a common car that you work on) then the second option for vehicle selection is super quick. You can directly input the vehicle identifier code under the ‘RB key’ tab, and then highlight the vehicle before continuing with your work.

Thirdly, the ‘Last 30 Vehicles’ tab is a useful feature if it is a car that you were previously working on and have gone back to. As the name suggests, the list will show you the last 30 vehicle selections for you to quickly choose from.

KTS diagnotics made ‘ESI’

The fourth option we have for vehicle selection is the ‘VIN Identification’ tab. This is a function that needs to have the VCI already plugged into the vehicle and, in most cases, it will quickly retrieve the VIN details by serial diagnosis from the mode 9 of Global OBD II. The VIN is then referenced in our databases and the possible vehicle selections are shown.

KTS diagnotics made ‘ESI’

Vehicle selection

Some manufacturers work better than others with this feature, for example the VIN on some cars doesn’t contain model-specific details and the list of vehicles offered could be quite long so selection ‘By Description’ would be better. In most cases the VIN readout will generally give a list of 1-3 RB key possibilities to choose from which can speed up the initial stage of vehicle selection. We have, however, seen some models that don’t even store the VIN in mode 9 of Global OBD II. In this instance you could manually type in the VIN and search the database for an RB key that way.

Once you’re happy with your vehicle selection you can use the main tabs across the top row of the screen to navigate through the software to perform the wide range of diagnostic testing and service related tasks and functions with the tool. As you can see, there are various ways to find the right vehicle within the Bosch software and with experience you will learn which way is best for you and the car you’re working on.