Sensor wires on 2007 Camry starting battery
 

There is a small connector on the starting battery of my 2007 Camry Hybrid. What is the purpose of those wires, a temperature sensor maybe?

If I replace the starting battery with a battery that doesn't have this temperature sensor (or whatever it is for) attached, how will that affect the vehicle?

Thanks in advance,

John

Re: Sensor wires on 2007 Camry starting battery
 

Yep. Temp sensor.

It will throw a continuous code that does NOT illuminate any dash lights.

The temperature sensor is effectively a safety feature, and it CAN be used to tailor the 12V charging algorithm, but I don't KNOW that Toyota does this.

Re: Sensor wires on 2007 Camry starting battery
 

Thanks for that.

In order to get the car going again, I put in a generic car battery (one without a temperature sensor). Car seems to work fine, but it does give a CHECK HYBRID SYSTEM display. Out of curiosity I removed the temp sensor from the original batter (super easy to do, it's just press-fitted into the top of the batter under one of the warning stickers). I put a meter on it and observed that at room temperature it's at 2200 ohms. When I press it between my fingers the resistance drops and when I cool it the resistance increases. So the sensor seems to be working.

So, I plugged the sensor back into the car. I was surprised to see that the CHECK HYBRID SYSTEM alert did not go away.

So I'm scratching my head at how the car knows that something isn't right.

When I find a proper replacement battery I'll install it, but if I do and the hybrid system warning still appears I'll have spent nearly $400 for a battery I don't need.

Thoughts?

Thanks,

John

Re: Sensor wires on 2007 Camry starting battery
 

Recommend you transfer the temp sensor to the new battery - duct tape it in place.

Disconnect 12V battery for two minutes. Reconnect. See if error goes away.

I may be mistaken on the "does NOT illuminate any dash lights" part. On newer Gen3 Prius where the temp sensor was implemented, it will not give any dash indication. In retrospect I can't say with confidence that's the case on the Camry. I've only dealt with a dozen or so.

Re: Sensor wires on 2007 Camry starting battery
 

Actually, I was able to clear the error by disconnecting battery and sensor, then connecting sensor first and then the battery. No more check hybrid system message. That might have taken me two minutes, so I may have tried your suggestion without knowing it.

When the sensor was disconnected the only indication was the check hybrid message. No lights...other than from my big smile at not having to pay $400 for a new battery :thumbs_up.

Thanks again for your input.

John