To say that the automotive industry is going through a change is an understatement akin to the epitaph inscribed on the headstone of the late comedian Spike Milligan, which reads “I told you I was ill”.I can remember joining this challenging profession in 1983 when the Master Technicians were tasked with the introduction of mainstream engine management systems. This was a time when a Maestro was a family hatchback, an engine analyser was as big as a double wardrobe and “CAN” was something that contained a fizzy drink. I would often hear phrases from mentors claiming “cars are becoming too advanced” and “there will be nothing left for us to do now carburettors and points have gone”.
Roll on 37 years, and the rumour mill is turning again. This time it is the rapid growth of electric vehicle (EV) sales and similar phrases are being shared among the great and the good. From my perspective, I cannot think of a better time to join our profession and embrace the opportunities that lie ahead. The role of the technician is more important now than it has ever been and it continues to evolve in direct proportion to new technologies. From the main dealers to aftermarket, from off-highway to renewable energy, electrification is here to stay and if you are not on board, you will be left stranded.
Make no mistake, regardless of the power source (ICE or electric motor) vehicles and machines will continue to develop faults and will most certainly require maintenance. While EV’s utilise an amazing power source, the vehicle infrastructure presents new diagnostic opportunities such as charging errors, contactor failure, inverter malfunctions, insulation and bonding faults, to name but a few. Couple these fault conditions to the usual ABS, steering, suspension and network errors and… “You’re gonna need a bigger boat” (to quote Chief Brody from the movie 'Jaws'). Several manufacturers boast of “connected cars” with intelligent on-board self-diagnosing systems. Early indications of such features confirm external verification is still required followed by rectification and confirmation of repair. Does this sound familiar? While our profession may be changing, the rules remain the same: To maintain, diagnose and verify components efficiently, test equipment and measurement techniques must be applied and inevitably evolved.
So, what now for PicoScope and where does this fit with EV and high-voltage (HV) applications? The ability to capture and correlate a multitude of signals to other events in real time, regardless of their nature (e.g. voltage, current, pressure, sound, vibration, etc.) becomes invaluable at any stage of maintenance or diagnosis regardless of the power source.
Let us take a look at a customer complaint of reduced range from a full EV vehicle with no fault codes or plug-in charging issues. Could there be a fault with the regenerative braking system?
Above, we used PicoScope to correlate current flow to and from the HV battery with the accelerator pedal position sensor and brake pedal switch. Not only did we confirm that the regenerative braking feature was functioning correctly, but we also verified the difference between regenerative charging during over-run and braking. The conclusion here was that the system was functioning correctly and our customer expectation of battery range required managing.
Moving on with EV applications, it should come as no surprise that a scope cannot do everything! While PicoScope can measure high voltages using a differential probe, and current flow with the relevant current clamp (and much, much more) there is also a need for dedicated test equipment. Zero-potential checks and insulation testing will become as regular as an oil service and these demands have been addressed with the introduction of the PicoScope EV Diagnostic Kit.
Zero-potential testing is arguably one of the most important measurements you will ever make, as your life literally depends on it! To qualify the absence of voltage, a robust test sequence in conjunction with Pico's new Two-pole Tester will ensure, beyond any doubt, that your vehicle/machine is shut down. Please visit the new Electric Vehicle Guided Tests within PicoScope 7 (v. 188.8.131.5266). Click on the Electric Vehicle icon and select Safety Tests > 0 V potential and open the Guide and settings file. Within this Guided Test you will find a link to a supporting video describing the application of the Two-pole Tester.
Post shutdown, insulation testing may be required. Not only during diagnosis but to qualify repairs and installations. Pico's new Insulation Tester has such measurements covered up to 1000 V, along with the ability to save and export data to qualify the captured results. The Insulation Tester can also be used for typical measurements you would expect from a hand-held multimeter, providing functionality beyond insulation testing. Please visit the new Electric Vehicle Guided Tests within PicoScope 7 (v. 184.108.40.20666). Click on the Electric Vehicle icon and select Safety Tests > Insulation resistance, and open the Guide and settings file. Within this Guided Test you will find a link to a supporting video describing the application of the Pico Insulation Tester.
Non-intrusive testing is fundamental to any diagnosis and 3-phase measurements are a typical example where the three 2000 A current clamps included in the EV Kit will reveal motor/circuit integrity where access permits. On the subject of non-intrusive measurements, the EV Kit also includes a Coil-On-Plug probe, which may raise an eyebrow for EV applications until you watch Ben Martins’ video, where you can learn about the detection of AC at 50 Hz.
At this stage, while we prepare for future challenges, we must not forget the opportunities presented by ageing vehicles requiring diagnosis and, hopefully, repair. I say, hopefully, as often the diagnosis may conclude that the vehicle is beyond economical repair. However, with that said, the diagnosis is still chargeable to the customer and reinforced using PicoScope.
In addition to what I have already mentioned, the EV kit includes a PicoScope 4425A, a 60A current clamp, a differential probe, test leads, appropriately rated probes and more, that can help you when diagnosing vehicles of the past, present and future.
I want to end with the memory of a tune played on Radio 1 in the 80s, which resonates as much now as it did then. The group was Timbuk 3 and the tune was aptly called “The future’s so bright I gotta wear shades”. I believed it then and I most certainly believe it now.