I left work today (42 mile drive, mostly freeway) and about 10 minutes after getting on the road, the triangle of death came on for less than a minute and then the check engine light came on. The hybrid battery drained to 1 bar and seemed to be running on just the engine, revving up and down to keep speed with lowered power. Got off the freeway and it settled into driving more normal and battery was charging up. Got back on freeway and same thing happened for the rest of my drive home. Turned off and it sounded like the engine cooling system was gurgling alot and there was a small amount of coolant below the radiator. Pretty sure it was from the overflow tube. Read code P0117 only. Do you think the coolant temp sensor could cause all that?
No. The coolant temperature sensor will not cause any of the symptoms that you listed except for the check engine light to come on. The P0117 code is caused by very high coolant temperature or a short in the wires from the ECM to the temperature sensor. My guess is very hot engine coolant temperature. Code P0117 will not cause the red triangle of death (master warning light) to come on. What scanner are you using to read the trouble codes? Most scanners are not capable of reading hybrid trouble codes. The first thing I would do is check the coolant level in the radiator and in the plastic overflow bottle. Most people do not check the radiator, and they only check the overflow bottle. Make sure the coolant is cooled down before removing the radiator cap. Coolant should be full all the way up to the top. Low coolant will cause the engine to run hot and could cause the P0117 code.
