Got a '09 that I gave to my daughter that doesn't make enough heat initially upon inspection. I thought it was taking awfully long for the coolant to get moving through the bottom hose so I replace the thermostat with a Robert Shaw balanced stat that's made to fit in this vehicle The car seems to take about the same amount of time for the bottom hose to start letting water through It is 30 to 38° out generally. I also noted that the coolant control valve up near the radiator only one hose was warm and the other was very lukewarm so I guess the three-way control valve is not able to open on its own or open enough looks like it's a motor attached to a gear that opens a port to let water come from the thermostat housing bypass through the control valve and up to the heater water pump between the brake actuator and the hydraulic part your foot touches the pump is mounted on the brake actuator bracket It is running but the hoses aren't hot enough like they are in my other two vehicles The coolant control valve I took off of another car that makes plenty of heat and the car still doing the same thing with the new thermostat and the control valve from another vehicle that when I put it back on the other vehicle the heat will run you out of the car. I'm kind of lost at what to do next at first I thought I had a radiator leak but after two days of filling and fooling around and what have you there in fact is no water coming out of the system It is full of antifreeze and that seems to be that no air pockets I can squeeze on the furthest hose away and bring the water right up the filler neck No problem. Another funny thing is is when I'm driving the car in the same temperature if I get on the highway and try to run two exits down to the sheets the red triangle will light up the green car on the MFD turns red and shows a temperature gauge through it and it just flashes on and off at certain times it doesn't stay that way then when I get to the sheets get out of the car and touch the hoses everything is still very cool The bottom hose is just starting to warm up and very little heat they'll come out of the center vents but over on the far edge left and right vents cold air is coming out but warm air is coming out of the middle but not warm like it should be. The air conditioning works wonderfully no matter the temperature the blower fan works at all positions and it seems my air is coming out the correct vents when selected even the damper door that goes from fresh to research seems to work fine this car is always had great heat to 5 years or so I've had it this just started as soon as I handed it to my girlfriend's daughter but these are the kind of people that can't beat themselves out of a wet paper bag at first I didn't think they knew how to turn the heat on so I went over and set it up for hot hot and hot and told them not to touch it except turn on the fan they've managed to do so and still have almost no heat when it's cold now when it gets up to 40° not so problematic. My other three cars here at the shop I'll make so much heat I have to turn it off after 5 minutes generally speaking course I'm dressed for the weather and whatnot. Anybody have any realistic ideas I can't imagine this would be a computer problem doesn't seem like it because everything's pretty basic and it's working including the air conditioning which is of no consequence in this weather.
I would chase the temp light problem first and the heater will likely follow. It appears the engine/radiator loop is standard with no restrictions caused by the Coolant Heat Storage System or the Heater/Heater Water Pump. Maybe the engine water pump is weak?
I was wondering similar but I also noticed that when I have the heater on the engine doesn't stay running like it does in my other three cars so this particular car while there's a call for heat and the car is on and ready the engine will shut off and not be anywhere near at temperature to provide any kind of credible heat in my other three vehicles that engine will not shut off as long as there's a call for heat and the heat's on whatever until it gets hot enough in the car that you're about to sweat to death then the engine will shut off then if you sit there and it gets cool and that thermistor in the car by your knee senses the temperature is not being up to snuff boom engine comes back on oh well back to the drawing board I guess the car has never had a coolant heat storage tank code and the pump does run at startup. I just find it kind of interesting about it not running till it gets hot enough on its own and this just all of a sudden started this car has had great heat for 5 years.
At first I thought the temp light and the triangle coming on was because of the big air bubble so I had a few days where the car wasn't being used so I just let it sit under the carport with the radiator cap off I can see no dripage no seepage nothing from any hose nothing and I just kept filling the radiator and for two days every time I'd come out to the radiator I'd put almost a quart of water in it. Then I'd come out 4 or 5 hours later and the water would be down in the neck where I couldn't see it and I would squeeze the furthest hose the way I can. And the water I could hear it sloshing around in the radiator but it wouldn't rise up in the neck so I pour more mix in bring it to the top of the neck and stop Walk away for 20 minutes come back and it'll be all the way down again I kept doing this for the couple of days that the car was off the road finally I got the coolant to stand at the filler neck right where the outlet hole is to go to the jug come back 4 hours later the water is barely moved but still visible in the neck in the 90 part of the neck which mine is plastic not metal. But I see no leaks nothing. But still no heat to speak of
If the engine was not overheating I might look at the damper on the heater core which blocks the airflow unless there is a call for heat. Or the ac amplifier/ecu itself,
Yeah I'm afraid I'm going to have to bust into some of that air box control business because with the car not calling for heat properly it seems like there's something not doing something correct and that business end of it.
No it doesn't seem like anything is ever getting hot enough to be any of that 200 and something degrees anywhere not on the block not even at the hot side of the back of the water pump before it hits the thermostat that gets relatively hot I wouldn't say $195°, but it's hot enough that I have to move my hand but on the other side of the thermostat man it takes 45 minutes of good fashion driving for that to even start to get warm with the old thermostat and the new one
Like a 18 to 21 in the morning and a high of maybe 40 during the day My other two generation twos have heat in 7 minutes in this weather The car we're talking about has no heat to speak of after 30 minutes
OK, those two controls rule out a temperature effect that would be present in all cars of this type. Can you see the armature on the blend door actuator on this Prius? Does it move when the control is toggled from recirc to fresh, or vice versa? I have been working through a similar problem on our 1998 Accord EX and in that case the blend door actuator was not moving. (Actually, any of them, all 3 climate control actuators failed at the same time. Thought it was the control unit at first, because how could they all go out at once, but nope, it was the actuators.) Anyway, on the Accord the blend door also controls a valve that lets coolant into the heater core, but I believe on the Prius that path is always open, so if there is no heat there is either cold coolant going through or the blend door is in the wrong position and won't move.
I don't know it's been really cold the last few days or so so I haven't been able to get down low enough to really look I think it is moving from research to fresh You can hear the noise pick up when it's in research and it gets quieter when it's in a fresh. Other than that I don't know what the other two doors are doing I know that when I go from face to floor to feet I can hear the motor hunting but it will move from face to face in the floor and to even defrost but when it gets there you can still hear the motor clicking like it's hunting to go back where it was It likes the face position all the time It never hunts in the face position. Move it from the face to any of the other positions and the air will go there but then you hear the constant click click click like something's gotten to its end of travel and it's reviewing whether it needs to move again which it does not so whenever I turn the car off or I'm sitting in the car and I'm on anything but the face position I hear this clicking so usually I move it back to the face position so everything's quiet and in the summer it's always in the face position for air conditioning which is predominantly our season here so nobody ever notices that something is amiss until it's freezing but now it's kind of funny because the lower radiator hose gets relatively warm on the pump side of the housing but on the thermostat side Man it is not even thinking about getting warm for about 30 minutes and then warm starts to get to the thermostat side and then it's just starting to get up the bottom radiator hose about halfway it hasn't even got to the radiator yet and then by then I'm usually tired of driving and fooling around I pulled back into the driveway and just leave it given the fact I have three or four of these sitting here at the ready with tags on them just haven't had the time All the other cars have 140° coming after vent You have to be turned off after 5 or 6 minutes because you're sitting in the car with your clothes on about to burn up.
There are usually 3 actuators: mode, blend, and recirc. By sound the recirc is working and the mode is working but failing (hence the clicking). No info on the blend though, and that is what determines if the heat works or not (assuming the coolant is hot). On this car they refer to the "air mix damper control servo circuit", which is a mouthful. Are there any codes? One can be set for that, and it won't light the CEL. I'm not entirely sure where this thing lives in a Prius, but from one diagram it might be the lower of two actuators on the driver's side near the center. Hmm, looks like it is the one which is a PITA to remove: that actuator looks a LOT like the one from the Accord. If the motor inside has not failed these can often be repaired on that car, probably here too. After taking it out test it dangling from the plug (no mechanical load). Also a good time to check that it is getting power and grounds are right. To repair the unit, first mark the position of the armature and the axle through it. Remove the armature. Then carefully pry it open (use a tiny jeweler's screwdriver under each of the "loops" that hold it closed and pry the case open with a larger screwdriver. At least one of the two loops on each side of the socket section will break - they are insanely fragile. Once it is open get all the gunk off the connectors that wipe on the large gear. It will usually be green and nasty. Spray them with contact cleaner so that they are pristine. Maybe bend them up a little (towards the gear). Pull out the large gear (before cleaning those contacts), flip it over to the side that has conducting material. Wipe off all the gunk. Spray that with contact cleaner and make it clean. Apply a thin layer of dielectric grease. Check that the two contacts for the motor are both firmly in their holders. Put the big gear back in, being sure it is in the position noted at the beginning for the hub. Close it up. Put the armature back on. Plug it into the socket in the car (no need to install, let it dangle), and change the heat position. If it moves then it has been repaired.If not, the motor may have failed, there is usually a test procedure for that. Don't apply 12V to the motor when it is not installed in the actuator - it may spin itself to death with no load. Also, some of these actuators have physical stops inside. If the big gear isn't in the right place those stops will prevent it from ever getting into a functioning position. If some of the loops that hold it together have broken put a zip tie through the nearest case hole (which isn't used for a screw) to keep it closed. Be sure the zip tie won't interfere with installation or the motion of the actuator.
I have an '05 that's completely apart in the dash area so I can take that off pretty quickly have a good look at it and that car was working fine when it was taken off the road as far as heat and AC no problems at all worked great was a Florida car
Great. If the '05 actuator works pull it out and plug it in (dangling) on the '09 (usually the cables going to these things are relatively easy to detach, even if getting out the actuator itself is difficult) and see if it moves. If it does, then you can worry about getting the bad one out, and if it doesn't, it tells you to look elsewhere in that circuit for the problem.
Is it possible to connect via the TechStream program? The engine data will be more informative, it will show all the sensor values for temperature, the position of the three-way valve. The critical errors that appeared will also be shown, including the values of historical errors in memory.
Yes it is possible I just don't really know what I'm looking at but I will hook up TIS this afternoon or evening and run the car a while and see if I can log some of the data just to see what we got I know coolant temp right now is stupid cold I mean if I get out and touch the hoses and whatnot it is ridiculous whereas my other three cars same scenario and the hose that's attached to the heater pump between the brake parts up on the firewall is pulling hot water You can feel it right there by the inverter pump that hose comes all the way down goes right to the side of the inverter pump and then shoots over to the water pump bypass or something I believe.
