diagnostic jobs
Resource Centre 4 min read

10 diagnostic jobs that might surprise you

Share Resource:
Diagnostics & Test Equipment How it works 4 min read

Resource Highlights

In this article, we breakdown the 10 diagnostic jobs that might surprise you.

With cars fast becoming computers on wheels, parts that were once simple remove and refit jobs, may now require reprogramming or adapting after installation. Failure to teach the new part how to behave using a diagnostic tool can cause the vehicle to exhibit the same fault as before, generate an entirely new fault or simply not perform as it should – be it higher emissions, lower fuel economy, poor engine performance or reduced safety. Either way, the chances are you’ll have a repeat visit from an unhappy customer, losing you time, money and potentially your reputation. So, to avoid any unwanted surprises, we asked our in-field service team for 10 diagnostic jobs that can catch even the most experienced technicians unawares.

  1. When fitting a new air filter on some diesel powered Mercedes-Benz vehicles i.e. 2013 Sprinter 2.2L, a diagnostic procedure is required to tell the ECU that it has been replaced.  This then adapts the MAF sensor readings to ensure the correct air flow measurement is calculated.
  2. Replacing a modern stop-start battery can take significantly longer than a conventional battery, because the vehicle’s energy management system must now be reprogrammed using a diagnostic device. If this is not performed, the stop-start system may not function correctly, resulting in increased fuel consumption and emissions. 
  3. After replacing an EGR valve, on a Ford Focus 1.6TDi 2011 for example, the valve must be readapted. If not, the pintle can break off and drop into the engine, causing repeated EGR failures, and potentially catastrophic engine failure.
  4. When installing air suspension springs on some BMW models, such as the 5 Series, a three-stage diagnostic process must be performed.  Failure to carry out these exact steps, in the right order, may result in the car sitting at different heights front to rear, or side to side, after replacement.
  5. windscreen wipers
  6. Windscreen replacement is no longer a straight-forward job. On vehicles fitted with Advanced Driver Assistance Systems, otherwise known as ADAS, technicians will need to perform either a static or dynamic calibration to ensure these safety-critical systems still function correctly.
  7. When a camshaft sensor, measuring both speed and position, is replaced on a Citroën C4 1.6D for instance, a diagnostic procedure is required to clear the learnt values from the old sensor, and place the ECU into learning mode for the new sensor.  Without this the vehicle owner may experience loss of power and poor fuel economy.
  8. oil can
  9. Even something as simple as a basic oil and filter change may now require a diagnostic procedure. Take a Volvo S60 1.6 petrol - the ECU must now be reset to reflect the ‘oil quality’ values of the newly replaced oil.   
  10. When changing brake fluid in an electronically controlled ABS system, a diagnostic tool is required to initiate a routine on the ABS ECU. By rapidly opening and closing the valves during the bleeding process, it ensures the air is purged from the modulator. Not doing this will result in the brakes not performing as they should. 
  11. battery
  12. Just to maintain the warranty on some electric vehicles, a battery health check must be performed using a diagnostic tool. This will measure the battery’s State of Health i.e. how much life it has left.
  13. When fitting a new control arm on a vehicle equipped with self-leveling headlights, the sensor must be reset using a scan tool, to ensure the headlights are always at the appropriate height for the vehicle. Failure to do this could result in a vehicle with incorrect beams, reducing visibility for the driver and distracting oncoming vehicles.

These are just a few of many examples. There any many, many more. Indeed, to get a feel for just how many, we took a look at our DS diagnostic software. For cars and light commercial vehicles alone, we cover more than 4,400 different engine types requiring adaption or reprogramming for MAF sensors. Over 1,600 for exhaust temperature sensors, 2,400 for Lambda sensors and a staggering 11,500 for EGR and EGR throttles. So, it’s no surprise that some technicians can be caught off guard.

Leveraging our expertise in pioneering propulsion technologies, the innovative tools gives you the ability to read fault codes, view live data and perform special functions for all the above and more. And across a wide range of vehicles too; 64 brands and more than 1,180 models and 30,750 unique system selections for car and light commercial vehicles. And 74 brands and over 680 models and 16,600 system selections for trucks, trailers and buses.  Including over 85% of the mainstream electric vehicle parc. 

So, whether it’s a routine, run of the mill job or a more complex service procedure, choose Delphi’s DS diagnostic solution. Offering in-built OE expertise, for time and money saving repairs, the only thing that may surprise you is just how good it is. Visit our diagnostics home page to explore the variety of diagnostic solutions we have, with something suitable for all workshops.

This article was written with technical input from our Senior Technical Service team. A variety of training courses are available at our dedicated centers. For more information and to book a course please visit our training information page.

The specified form no longer exists or is currently unpublished.

Related article resources and products

    Part diagnostics fuel injection electronic test kit
    Diagnostics & Test Equipment Fuel Injection Diagnostic

    Electronic Injector Test Kit

    With today’s Common Rail injector technology, it’s no longer sufficient to just measure resistance to check a coil’s health – you also need to measure inductance for an immediate and accurate assessment. Previously separate tools would have been needed for this. Not with our Electronic Injector Test kit. Otherwise known as the ‘buzz tool,’ or part number YDT720, you’ll be able to quickly test the electrical integrity of all makes of solenoid Common Rail injectors on vehicle. The simple,hand-held tool measures the injectors core criteria, allowing you to quickly compare values and identify if any are not within a comparable performance range, or confirm specific electronic failures which may indicate an unrepairable injector. You can also use it in conjunction with our solvent cleaning kit to resolve early-stage lacquering. All with just one tool, saving significant time and cost for the garage.
    Diagnostics & Test Equipment

    Pass-Thru Diagnostics

    Our DS-Flash™ pass-thru package does what its name suggests – it allows garages to ‘pass-thru’ to vehicle manufacturer’s websites to access valuable repair and maintenance information. With DS-Flash you’ll be able to perform dealer-level diagnostics, download software updates, reprogram ECUs and access OE technical data and service schedule information, without the need for expensive dealer-only tools. The full kit is compliant with VM programming requirements and comes complete with a DS-Flash™ VCI, cables, a battery support unit and a laptop PC, pre-configured for key brands. Users will also benefit from our 12-month support package, which includes training and technical support for both the equipment, registration to the VM web portal and installation and use of the VM software. So from now on, jobs that were turned away, or referred back to the dealer network, can now be managed in house.
    Part diagnostics fuel injection hd3000 high pressure tool
    Diagnostics & Test Equipment Fuel Injection Diagnostic

    HD3000 High Pressure Diagnostic Tool

    Designed for specialist workshops, our patented HD3000, part number YDT840, simplifies the diagnosis of faults with current and future-generation diesel and gasoline high pressure fuel systems, on all vehicle types. With one tool users will be able to safely set and electronically control any pressure testpoint , up to 3000 bar, in order to investigate the full range of pressures and analyse the performance of the fuel injection system – previously this level of flexibility, accuracy and pressure capability could only be achieved with a system-dedicated test bench. Containing an electronic control device, hydraulic block and electrical device, it incorporates multiple dedicated test routines, as well as an IMV cleaning procedure. All this can be achieved without changing any ECU parameter, dismantling the fuel injection system, or taking the vehicle out on a road test – helping workshops save valuable time and deliver faster service turnarounds.
    Part diagnostics fuel injection lo35 low pressure tool
    Diagnostics & Test Equipment Fuel Injection Diagnostic

    LP35 Low Pressure Diagnostic Tool

    Designed for the garage technician, LP35, part number YDT810, is a highly precise, ultra-fast, affordable hand-held tester for the low-pressure side of light, medium and heavy duty vehicles. With a single tool, you can perform quick and accurate pressure analysis across a wide range of positive and negative pressures, from minus one through to positive 35 bar -that’s why we called it the LP35. Unlike other entry level equivalents, it’s also compatible with most low-pressure circuits, as well as different fluids, so you’ll no longer need separate negative and positive pressure tools, saving both time and money. Add to this its static and dynamic functionality, and you’ve got a highly versatile, highly capable low-pressure tool.
    Part diagnostics fuel injection hd3000 high pressure tool blueprint
    Diagnostics & Test Equipment

    Fuel Injection Diagnostics

    Due to the design of today’s advanced fuel injection technology, electronic diagnostic tools require additional support to accurately trace faulty components – the ECU diagnostic software  can often go no further than failure mode identification, which does not always pinpoint the particular part of the system that has failed and can result in the unnecessary replacement of complete systems. That’s where we come in. We know exactly what is required when diagnosing this technology – after all, the chances are we designed and manufactured it in the first place. So, we’ve developed a range of simple, low-cost, on-vehicle diesel diagnostic tools to help you and your customer save time and money.
    Part diagnostics fuel injection sealed rail kit
    Diagnostics & Test Equipment Fuel Injection Diagnostic

    Sealed Rail Diagnostic Kit

    Because Common Rail systems operate at extremely high pressures, any loss in pressure will have a knock-on effect on the vehicle – causing a progressive reduction in power and even a complete engine shut down. It is therefore imperative that any such issues are identified and resolved as early as possible. We have just the answer. Our Sealed Rail diagnostic kit, part number YDT850, provides simple, low-cost on-vehicle capability for all makes of Common Rail pumps and injectors. Consisting of a sealed rail pressure tester and injector back leakage measurement equipment, users can check the pressure being generated by a Common Rail pump and identify individual injectors that fail, meaning only faulty components will need to be replaced.
      where to buy

      Find out where to buy Delphi parts

      where to repair

      Find your nearest Service & Diesel Centres

      Select your Region