Good Afternoon,

I am new to this forum and did not quite find what I was looking for on the other threads.

After my 2006 HCH died in my work parking lot because I forgot my keys in it, the brake system light came on then went away after a restart after the jump.

However, now my regenerative braking is functioning right. It is no longer charging from braking, just from foot of the gas decelerating. Is this an indication that I need a new 12v battery or that I need my brakes and regenerative system checked?

 

How did leaving your keys in the car cause it to die? Did you leave lights on?

Flattening a 12V battery that is > 3-6 months in age can severely damage it. If your battery is > 2 years old, it is highly likely it is severely deteriorated.

Step 1 is to confirm 100% that your 12V system is good. That means a LOAD test of the battery at a garage or auto parts store. Voltage check doesn't cut it.

Step 2 is to confirm that the (-) battery cable and the ground straps connecting the CVT to the unibody and the engine to the passenger side engine mount are in good shape. That requires a continuity test. Sight and touch give zero indication of health, though they can confirm bad - crispy, stiff and/or corrosion indicate bad ground straps.

Step 3 is to check for diagnostic trouble codes even if you don't have an IMA or CEL indication.

If you have no codes, disconnect 12V battery for 2 minutes. Reconnect 12V battery, start and allow car to charge the IMA battery at idle. Do not drive car until idle charging terminates. If the charge terminates at 8 bars, you may have an ailing hybrid battery. If it terminates at 3-4 bars, it's a good sign that your hybrid battery is in decent shape.

Your hypothesis on regenerative braking is extremely unlikely. If you get any charging at all during "engine braking", the regenerative braking system is functioning.

 

No, I just left it in the forward position, one click back from turning it on. I usually leave it there to roll the windows up or down while I nap, then roll them up and take it out and go in. My alarm startled me so I thought I was late and dashed out without remembering to do the rest of it.

I assume the car battery hasn't been replaced in a while. The car sat before I got it from them and needed all new tires, new oil, a filter for the cabin, etc.

Okay so step one - have my battery tested. I think its safe to assume that its old and needs replaced though. Then I will do the code testing bit.

Its only not charging when I use the brakes, the other charging method is working fine and all of it worked fine until the 12v died in the parking lot and needed jumped.

 

Okay. So key in the ignition switch in the ON position... yeah... that will do it.


12V issues can create all kinds of problems.


If this is the same 12V that was in it while it sat, just replace it. IMHO, ditch the plastic shrouds and install a 51R instead of the 151R. 40% more capacity.