MT03A

Ask any questions relating to the PicoScope hardware or kit contents here.
If you have any questions prior to purchasing the kit post them here.
Post Reply
liviu2004
TwoWaves
TwoWaves
Posts: 472
Joined: Sat Mar 19, 2016 8:23 am
Location: Netherlands

MT03A

Post by liviu2004 »

I saw on youtube what it does, question is, when is it needed, what example fault codes car had and are they any bad examples and which vehicles?

ben.martins
Pico Staff Member
Pico Staff Member
Posts: 539
Joined: Tue May 16, 2017 1:02 pm

Re: MT03A

Post by ben.martins »

Hi liviu,

I think the follow up video will answer a number of these questions but I'll try to give some examples where we have been using this tool.

We've seen a requirement in vehicle manufacturers technical information surrounding high voltage, 3 phase electric motors where a technician is required to take a milliohm measurement from the motor. In the case of Toyota, this may be on the back of a fault code for P0A78-113 for Drive motor performance suggesting an over current.

An over current fault code suggests a possible short in the coil of a phase. This can lead to the resistance of that phase being slightly lower than the other two. Less resistance means more current can flow but how can you prove this? Using the MT03A, you can now connect all 3 phases in one test where the software will show how each phase compares to one another. The results are then displayed in bar graphs to represent the 'balance' between the windings.

There might also be a need to use refurbished motor, especially with component shortages. Prior to fitting a replacement, the motor can be tested using the MT03A to ensure the part going in is good. This was apparent from a company that was fitting second hand gearboxes but not testing them before fitting. When fitted and finding they didn't work they were discarded to one side. Upon testing the gearboxes came with the cables to the inverter and the MT03A was used to determine it was the cable at fault not the motor.

Other areas where the MT03A could be useful, is for the people carrying out the refurbishment. Getting a before and after test along with a print out stating the condition of the windings after a repair would be useful for the customer.

Moving away from motors, the MT03A can also be used to determine the resistance for the earth bonding cables between high voltage components and the chassis. This is especially important when it comes to insulation testing. Imagine if there was a build up of resistance between the body of the HV component and the cable. If you were to carry out an insulation check using a megohmmeter and used the vehicle chassis you could actually get a false positive. The MT03 ensures a minimum 200mA of current which is required for ECE R100 regulations for earth bonding with resistances below 0.1 Ohm ensuring the repair doesn't have any comebacks.

For conventional ICE vehicles the MT03 can also bring benefits to testing. Earth cables to engines, battery to chassis ground points, starter motor cables can all be checked. Other applications on ICE vehicles is the introduction of 3 phase brushless DC motors. Whilst I've yet to see actual values in the technical information, the MT03 could still be used to determine the balance of the windings. These brushless DC motors can also be found on turbo and EGR actuators and some VVTi controllers.

Low resistance measurements can also be found outside the automotive and transport industries where the MT03A could also be used. One example could be lightning protection systems where the resistance needs to be very low!

I hope this helps. There will be more content out soon for this device which will show it in action and how it has helped.

Kind regards

Ben

Post Reply