Tool Q&A: Want to do hybrid repairs?

Tools, equipment and advice from getting started with hybrid repairs to rebuilding HV batteries.


This is how it works: Connect one meter lead on the ground for the HV cable/motor generator/etcetera and the other on the power side. Then, conduct the insulation test. Your reading should be about 2.2 gigohms on a Honda. If you have anything less, such as 5.4 million ohms, then you have an HV leak somewhere such as shorted windings in the motor generator. This requires a transmission rebuild to repair. The insulation test might be the only means you have to prove to the customer that their HV DTC can be repaired by a big money repair.

Q: Do I really need training?

A: At a minimal, you will need safety training. You don't let an employee who is brand new in the industry set a lift or do a brake job until you properly train him first, correct? In the same way, you need to have a thorough understanding of electricity and model-specific safety precautions before you do any serious work on these vehicles.

Even to do an oil change on a Prius you need to disable the smart key so the vehicle will not start itself up in the air if the vehicle has not been turned off, which is hard to tell for some people being that the vehicle in auto-stop mode does not make noise. If you don't get at least a day of hands-on training on hybrids, you probably should not work on them. It's not worth the risk. Remember, if the vehicle powertrain has powered down, the vehicle will not restart unless commanded to do so.

Q: Are there other methods to repair hybrid vehicles?

A: Of course. Many of the strategies are taught by training organizations, but they are not the only methods to diagnose and repair vehicles.

Different industry experts come from varying perspectives. For example, one trainer may have a different method of testing used HV battery cells using ohms or some other means. Another may recommend only buying a new HV battery from the dealer as required in OEM test plans and a hybrid battery rebuilder/manufacturer will have their own proprietary methods they feel is best.

The recommendation of Professional Tool and Equipment News is to always use the safest method available and to employ strategies that help you fix real vehicles in your shop. Always use discretion when employing new diagnostic strategies and repair techniques.

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