Prius gen 2 2007 US - p0420 p1116 p1150

welcome!

what are you reading codes with?

why did you replace the coolant control valve?

 

Where did you get that from? That fortune cookie text is incorrect for that code, big clue Prius only has one bank.

DTC P1150 | Coolant Path Clog of Coolant Heat Storage System

Trouble Areas

• Coolant heat storage tank outlet temperature sensor
• Water valve (coolant flow control valve)
• Cooling system (clogging)
• Heat storage tank
• ECM

Inspection Procedure - DTC | P1150 | Coolant Path Clog Up For Coolant Heat Storage System

 

I am currently dealing with this issue right now. Except I’m not getting the p1150 code. I’m thinking it’s the engine coolant temp sensor. What ended up being the solution? I have a 2007 Prius.

 

So, does that mean you have P0420 and P1116?

Have you looked in the repair manual (RM) for what those codes mean?

The RM says that if you have P1116 and other DTCs then repair the other DTCs first. This means that if you have the above two codes, you should pursue the P0420 first.

P0420. This code does not mean your catalytic converter (CC) is bad, necessarily. The performance of the CC can become inefficient if the engine is not performing well, specifically if the fuel trims are excessive, the engine is burning excessive oil, or unmetered air entering the system after the MAF (mass air flow) sensor, as three examples. Exhaust leaks are another. You need to eliminate the exhaust leaks as a possible cause and then check the engine for anything out of spec. Specifically, you should check that the fuel trims are in spec. To do this you will need a good scan tool like Techstream (laptop-based) or an Autel MAXI AP200 (phone or tablet-based). There are other tools reviewed here (Gen2 OBD2 app review), but they are not good enough to diagnose these codes.

An engine that burns excessive oil will render the CC inefficient eventually so, anything that you can do to stop the oil burning, you should investigate. If the oil burning is caused by a worn engine, a replacement low mileage engine is really the most economic option. That's assuming the car is in an otherwise very good condition such that you deem it worthwhile keeping it going.

Some information about the P1116:

DTC Detection Conditions:

• Temperature change during hot coolant recovery: 3°C (1.8°F) or less;
• Difference between CHS tank outlet temperature and engine coolant temperature during hot coolant recovery: More than 25°C (45°F).

Trouble Areas:

• Coolant heat storage tank outlet temperature sensor;
• Cooling system (clogging).

MONITOR DESCRIPTION:
The coolant heat storage (CHS) tank outlet temperature sensor is used for monitoring coolant temperature in the vicinity of the outlet port of the heat storage tank of the CHS system. The resistance of the sensor increases when the CHS tank outlet temperature is low, and conversely, the resistance decreases when the temperature is high. The changes in resistance are reflected in the voltage that is output by the sensor. The ECM monitors the sensor voltage and uses this value to control the CHS system properly.

If the sensor output voltage deviates from the normal operating range, the ECM determines that the CHS tank outlet temperature sensor circuit has malfunctioned, and sets a DTC.

Examples:

1. No changes occur in the CHS tank outlet temperature sensor signal (over 1°C (1.8°F)) after a predetermined length of time has elapsed from the start of the coolant recovery.
2. A significant difference (over 25°C (45°F)) exists between the engine coolant temperature signal and the CHS tank outlet temperature sensor signal after a predetermined length of time has elapsed from the start of the coolant recovery.

 

Im having the same issue as above. 2008 Gen II 331,000 awesome miles. License tags due at end of month but had a lingering MX light on the dash. Was running rough and I was pretty sure it was spark plugs. Took it to Toyota and they confirmed it and replaced the plugs. Now it runs great but MX light is still on. P1116, P1121 and P1150. Toyota recommended the Water control valve for $800. I decided to change it myself for $100 and some cursing. Took it for a drive and still had the MX light. Got on the highway up to 80 mph and the Triangle of Death appeared. I slowed down to 65 and it was intermittent to the next exit and then the red triangle stayed off. A few small hills on the way home would drive the RPM's back up again and the red triangle would come back and then go away. Ill have to find someone with an OBD reader tomorrow.

Anyone here have ideas?

 

UPDATE: Made another trip to Autozone today, Plugged in thier OBDII. Got a new code for the coolant temp sensor. Bought that and went out to the car and the maintenance light was out. I took advantage of that and went straight to DEQ, passed the test and went back to Autozone to return the temp sensor. BUT... at about 40 mph, I still get the triangle of death. Which may not be deadly... yet. The triangle goes away when I slow down or stop at an intersection.

So I picked up a bottle of coolant for the car as both reservoirs were low. Topped them off, a little more than a quart Im guessing, then I drove it home and parked it for the day. Im thinking that all this might be because of some air bubbles that are still working themselves out of the system. Ill go on another city excursion tomorrow, say 40 miles total and see what happens.

Will a OBDII reader tell me whats going on while Im driving when the Red Triangle displays?

 

For the engine coolant loop, I hope that means you removed the radiator cap (under the black front shield) and checked the level in the actual radiator.

 

I might expect that you have a coolant sensor code and a "master warning light" (RTOD) because the cooling system wasn't properly filled and bled after replacing the coolant control valve.

What is the coolant level in the radiator? (Hope you didn't hurt the engine by overheating.)

Posted via the PriusChat mobile app.

 

And THAT^^^^ is exactly what it was. I burped the system several times already. I drove it on the highway and the Red triangle never returned. No new messages at this time.

I feel I have learned a lot about my car this past week.

Cheers!

Yes, Indeed!

All is good now. I look forward to adding many more miles to my car now!