my 2010 with 222k miles has started acting up in two ways that i think are related. but I am definitely interested in alternative diagnoses 1 it sometimes sounds like its pinging when its all warmed up and starting from a stop. 2 when using the brakes, coming to a stop (again all warmed up) the car will surge forward until i step much harder on the brakes. it feels like the regenerative brakes cut out on me way way too soon and the computer did not compensate. i drive for uber so there is a lot of stop and go for hours,and it is summer. could the battery be overheating and kicking off, without it triggering the check engine light? putting enough extra stress on the engine at low speeds to make it noisy and cause the braking anomalies. at 222k miles its probably a good idea to swap out a few battery cells and replace the spark plugs flush the coolant...no matter what.
i think your onto something. pick up a copy of tech stream and see what the cells are doing under load. at what speed do the brakes feel like they are not working?
Check your brake pads to make sure they are not low. Clean your egr circuit. My guess is your car idles kinda rough when your SOC is low (2bars)
What is your traction battery state of charge (SOC) when this occurs? How strong is your 12V battery?
the 12v battery seems healthy. but Ill load test it so far the braking issue has happened twice both times after about 4hours of driving and after a short stint of mildly aggressive stop and go driving with the battery soc indicating 90%. the low speed pinging or knocking i can make happen if i draw the soc down to 20% i should definitely clean the egr when i do the plugs, but the car idles unloaded smoothly. it only sounds wrong loaded at low speed. it may simply need heaver weight oil at this point.
