Red triangle & P1116

welcome to priuschat! do you have headlight leveling system?

 

P1116 says that the coolant control valve (it routes coolant in and out of the thermos) is sticking. This is a common occurrence in a Gen2 Prius and a dealer would say it costs about $350 to repair. The good news is that it is often caused by a low level of your engine coolant (Toyota type SSL) and if you fill the reservoir, the valve may recover since the coolant acts as a lubricant.



JeffD

 

when you put something heavy in the back, the lights point up and the sensor adjusts them back to level. in the early models, moisture was getting in and causing corrosion. i think jeff has your problem nailed in post #4 above.

 

besides the coolant control valve?

 

There are two separate coolant loops and two reservoir tanks. The Valve is in the engine coolant loop; not the Inverter coolant loop.

My P1116 alert showed up when the dealer failed to fully bleed out the air bubbles when doing the first drain/refill of coolant at 100k miles. My engine complained of overheating and the P1116 occurred. I had the dealer tow my Prius back and bleed/top off the engine coolant (note the reservoir may be full while an air bubble is stuck at the valve) and declined the valve replacement. That was 153k miles (over 5 years) ago and the P1116 has not re-occurred.

JeffD

 

did you top up the coolant reservoir as jeff advised?

 

The headlight leveling sensor has three main trouble spots. The inside of the sensor, the connector, and the pivot arm. Any one of those three items can cause the leveling sensor to malfunction and light up the symbol on the MFD and the red triangle on the combination meter.

Check the pivot arm for freedom of movement. Check the male and female sides of the connector to be sure they are free of corrosion. If all three items are good, then the problem may be at the ECU which would be bad.

 

That's great news.

 

Just a note: as air bubbles clear out of the loop, your engine coolant reservoir level may drop again. P1118 is an overtemp alarm at the thermos so it is also related to the coolant flow valve. Just keep adding coolant as needed and hopefully the alarms will cease.

JeffD

 

You need to remove the large black plastic panel that covers the radiator, for access to the radiator cap. Then you can remove the cap and look at the coolant level within the radiator. The level must be at the very top of the radiator neck. It is probably much lower, since your engine is still overheating.

To remove the large plastic panel, notice there are six plastic fasteners. Use a Philips screwdriver to rotate each fastener as you exert upwards pressure on the panel. The fastener will pop out.

As previously stated, you may need to check the fluid level in the radiator and overflow container for several heat/cool cycles. The fluid level should stay at the full mark and the overheating icon should stay off. If you cannot make this happen, then you will need to visit your dealer or seek other professional assistance.

It could be that your engine coolant pump is leaking - look at the pump pulley and the air conditioner compressor housing for a pinkish residue which will shows the engine coolant is leaking out of the coolant pump bearing.

 

The sound is either the pump that empties the Thermos (via the Coolant Control Valve, you can also hear it when shutting off your Prius as it fills the Thermos) or the Brake Accumulator pump.
The sound is normal unless very loud which cold be a symptom of the stuck valve.

JeffD