P0116

Recently my engine light came on, scanned it and got P0116. Anyone have any experience with this particular code? Haven’t found anything online specifically with Tacomas.

 

Coolant temp sensor.

 

Either the Engine Coolant Sensor is not reading correctly, or the engine Thermostat is not operating correctly. I just replaced the Thermostat on my Father-in-law's 4Runner because of this code. Has been fine since.

 

Thanks guys. I’ll try and look at the sensor first before the thermostat. Hopefully I can avoid having to drain coolant.

 

it is most likely the thermostat and you will have to drain some of the coolant to replace the temp sensor

 

Thanks for the heads up.

Light came on while warming the truck up on a cold morning, and I have notice a difference in fuel consumption. Hopefully I can get this sorted out.

 

Cold or inaccurate temp readings will cause the truck to run rich...thus affecting mileage. With a 2016, it wont hurt to swap out some coolant anyway. It is super easy to drain and fill.

 

Does anyone have experience changing the whole thermostat assembly? Is this the more likely solution? V6 you can’t just swap out the thermostat, have to replace the whole assembly, and ordering the part is going to be more expensive for me. Just wanted to double check.

 

Thermostat housing is very easy to get to. Sits in front of the motor just above the fan clutch. 5 hose clamps I believe, three 10mm nuts, one wire harness clip and plug and you are out. RockAuto has the Aisin for like $60 plus shipping. That includes the thermostat and sensor. Or Motorad for about $80. Not sure where you are located but shipping should be about $12 in the states.

 

I opened it up yesterday, just wanted to double check before I go ahead and order it. Where I’m located it’s going to take maybe a week or more to get one. I appreciate all of the information!

 

Light came back on today, same code.

I replaced the thermostat assembly about 2 weeks ago, nothing out of the ordinary since.

Any more ideas?

 

How often was the code showing up before the thermostat change? Did it take weeks or days?

Looking at the service manual, it only gives two options, change thermostat or change sensor. It is possible that both were failing at the same time. If you do change the sensor, and the code returns, then wiring is next. I would check the wiring quickly before changing the sensor though.

 

The new thermostat housing should have come with a new sensor installed.

 

It came on for about 10 days before I replaced the thermostat. Stayed in consistently. Light had been off since the replacement.

 

It was from Toyota. So I imagine the thermostat housing isn’t the issue.

 

Did the Toyota housing come with a new sensor installed in it?

 

I’m not sure, this is all new to me. Would it be inside the assembly?

 

Did your housing come with this plug sticking out of it?

 

It did, I have it plugged in. I’ll disconnect it and clean. Could be something compromising the connect?

 

I would check the connector pins. Make sure they are clean and not full of junk. Also check the visible part of the wires to make sure there isn't a break or insulation worn. Sounds like an intermittent open that is causing issues.