Pre-purchase inspection checklist of used hybrid car

Hybrid cars posses one of the finest technologies in the automotive industry. Having one is a dream come true for some people who like hybrid cars. Notwithstanding, when buying a used hybrid car, proper inspection should be done before purchase as the technology is complex and some parts and repairs can be expensive.

When inspecting a hybrid car, general pre-purchase inspection guidelines should be followed then in addition, this guide should be strictly followed.

There are general car pre-purchase inspection checklist but since hybrid car technology is quite different, there are a host of other things to be checked to ensure you don't acquire a lemon.


What to check when buying a used hybrid

1. Use a scantool to see if there are trouble codes.

2. There should not be check hybrid system or check VSC (vehicle stability control) system on the dash. They can signal problem with the high voltage system, batteries, engine, braking system and stabilty control system.

3. A constant loud high voltage battery fan noise signifies a weak and overheating battery module(s). Pay attention to this noise.

4. Check the brake pedal to see that it is not hard or spongy when braking as this can signify problem with stoke sensor, brake cylinder or brake actuator.

5. Excessive brake actuator priming signifies a brake actuator that is already faulty or near end of life. It is supposed to prime to maintain desired pressure in the brake lines but not to frequently and not too loudly.

6. There should not be knock sounds as this can be a sign of mechanical problem. It can also be a sign of issues with the ignition or fuel supply system since the Atkinson cycle engine used in hybrid cars is high compression engine that can give knock sounds easily when there are issues. Even when an ignition coil is bad, it will vibrate and give this knock sound.

7. The inverter/conveter system should be checked to see that it is not overheating. Under normal operation, you should see coolant circulating in the coolant reservoir of the inverter/converter cooling system. When the coolant is boiling, it shows that the system is overheating.

8. Check the brake actuator to see that it has not been bypassed and brake lines looped.

9. Check the maintenance history of the car. Particularly, if the transmission fluid was replaced, it must be with the recommended eCVT (electronic continuous variable transmission) fluid. Any other type of transmission fluid will destroy the transmission in little time.

10. Check the battery level indicator on the dash or navigation screen when the car is running to see that the charge state is not erratic (for example, jumping from fully charged state to low charge state).

11. Check the MPG readout to see that historically gathered fuel economy data shows that fuel consumption is okay. On a drive test, monitor recent MPG values too. A hybrid car with bad fuel consumption can signify issues with the hybrid system especially the traction battery (high voltage battery). You will see the manufacturer fuel economy specifications in the owners manual. Note that those values might not be achieved practically as it depends on drive condition and some other factors.

12. Check the 12V accessory battery. Hybrid cars use AGM absorbent glass mat) 12 volts batteries and not normal flooded acid batteries. If you have a voltmeter or a multimeter, check the voltage at the terminals of this battery while the car is running. If the charging system is fine, it should measure about 14 volts.

13. Check the air conditioning system. This is important because hybrids use special AC compressors that are not belt driven and are quite pricey.

14. Watch out for other strange noises especially from the eCVT transmission. It should not be noisy.

15. Check to see if the system switches from engine running mode to hybrid mode and vice versa.