Morning all,
I cleaned out all the dust bunnies the other day - it was clogged solid - and noticed that it looks like it's supposed to spin. I also have a (50) HEATER CORE TEMPERATURE SENSOR CIRCUIT SHORT TO GROUND. (FAULT TYPE = CURRENT) so I realise this may be making my temperature fluctuate.
My questions: is that sensor motor spinning all the time? What is the part number for a new one if mine is shagged please? I had a look on Allbrit but I can't find that sub-assembly.
thanks all
Ok I have accidentally found it searching for HEVAC bulbs, BTR 0909
The fault you've reported isn't the aspirator. That's there to sample cabin temperature. It is supposed to spin all the time the aircon's running.
Cleaning it out is a good thing though as its fundamental to the HEVAC knowing what heat cabin's at.
Heater core temp sensor is on the input hose down by the heater matrix. Main purpose in life is to not allow the aircon to blow demanded warm air until there's enough heat in the coolant to provide warm air. That way the system doesn't (shouldn't) send an icy breeze up your leg when you first start the car on a cold morning!
By the way- what diagnostics are you using? I'm a bit puzzled by the term heater core temperature sensor, as it isn't referred to as that.
There's a heater coolant temperature sensor (one I've talked about above) and an evaporator temperature sensor, which sticks into the airstream coming out of the evaporator.
Hi OB,
I have a nanocom, not the most intuitive but it didn't break the bank. I'll order a new heater coolant temp sensor this week. I get plenty of heat and then I get an icy blast. I found that currently I leave the passenger side on 26-28/HI and it stays toasty in this cold weather.
I did have a leaking core o ring many years ago and fixed that by tightening the screw back up. Thanks for the info
Have you checked with Nano to see what temp it's reporting?
Did my heater core sensor a few months back. Book symbol on display when car got up to temperature but no other symptoms. Book symbol went off if I turned car off and back on. Book symbol would only come back if I let the car cool down for a couple of hours and then restart it.
I had no heater problems though. Just the book symbol.
As Orangebean says, the sensor is right under left side of drivers dash footwell. Clipped onto the Inlet pipe of the heater core. If you have big shovel hands, you may need the assistance of a small child. Lol.
Orangebean wrote:
Have you checked with Nano to see what temp it's reporting?
I have found the engine coolant temperature screen, but haven't seen anything for cabin temp sensor yet. Where is that then?
blueplasticsoulman wrote:
Did my heater core sensor a few months back. Book symbol on display when car got up to temperature but no other symptoms. Book symbol went off if I turned car off and back on. Book symbol would only come back if I let the car cool down for a couple of hours and then restart it.
I had no heater problems though. Just the book symbol.
As Orangebean says, the sensor is right under left side of drivers dash footwell. Clipped onto the Inlet pipe of the heater core. If you have big shovel hands, you may need the assistance of a small child. Lol.
I'm shovel handed hahahaha.
You can see everything the the heating system is seeing on the Nano. Go to HEVAC, Inputs, Values and the screen will show you:
· Ambient temperature (c): This reading gives the external air temperature or air entering the ventilation system.
· Aspirator temperature (c): This reading gives internal cabin temperature.
· Evaporator temperature (c): This reading gives the evaporator unit's temperature.
· Heater core temperature (c): This reading gives the engine coolant temperature where the coolant enters the heating system.
· Road speed (Km/h): This value is generated by the ABS ECU using information from its wheel rotation sensors.
· Road speed (mph): This value is generated by the ABS ECU using information from its wheel rotation sensors.
· Engine running: Y or N
· Solar sensor (w/sqm): This reading gives the effective strength of the sun as detected by the Solar Sensor mounted beside the Alarm LED on the top of the dashboard.
· Distribution motors (%): This gives the current feedback position of the motor that drives the flap controlling air distribution inside the vehicle. As the distribution buttons are pressed the flap should move to the position which gives air flow to the selected direction (feet, face, screen etc.).
· Left blend motor (%): This gives the current feedback position of the motor which drives the flap controlling amounts of hot and cold air to be blended together (effectively the temperature of the air coming out of the vents). As the requested temperature is changed by the user the flap should move.
· Right blend motor (%): This gives the current feedback position of the motor which drives the flap controlling amounts of hot and cold air to be blended together (effectively the temperature of the air coming out of the vents). As the requested temperature is changed by the user the flap should move.
· Left blower return: This is the feedback value returned back to the Hevac ECU from the left blower motor, used by the ECU to determine the actual voltage at the motor. This reading value also allows the Hevac ECU to detect Blower motor faults.
· Right blower return: This is the feedback value returned back to the Hevac ECU from the right blower motor, used by the ECU to determine the actual voltage at the motor reading. This value also allows the Hevac ECU to detect Blower motor faults.
· Air conditioning grant: When the A/C button is pressed an active low signal is output to the engine management ECU (The Request). This then looks at factors like engine temperature, load, current acceleration etc. and according to when these conditions allow, grant Air conditioning. This involves it engaging the clutch to drive the Air Conditioning pump, altering its internal fuelling to compensate for the load imposed by the pump, managing along with the Hevac the Condenser fans, and also telling the Hevac that Air Conditioning has been granted.
Ahhhh that's where that lot is. I'll have a look tomorrow when the neighbours are out so my chugging doesn't annoy them too much! I'll take readings as well and up date you
If you look in the Downloads and Support section of the Nano website you'll see a Technical Info sheet for each of the car's systems. Gilbertd's post above is an extract from the HEVAC one.
They're worth downloading and having handy if you're using the Nano to interact with the various ECUs
Thanks OB I have that now - I'll have a read over night.
thanks so far guys
On nano my temp shows as -38.8. I'm sure that it wasn't -38 in my car hahahaha. Also that little sensor in the cubby isn't spinning so I'm guessing that it's goosed as well.
They normally drop to -40 when faulty, so yours is only very nearly faulty :)
I've got a spare little spinny thing kicking around somewhere if you get stuck. That one is the aspirator temperature and shows you the temperature in the car. If it thinks that is -38 degrees the heater will be going flat out all the time trying to warm it up. The heater core temperature sensor is the one that should be clipped to the pipe going into the heater matrix. They do fall off (small tie wraps are the usual answer) but even then would be showing ambient temperature so if that is showing -38 it is dead or disconnected.
Thanks Gilbertd - I'll ask you if I need it and thanks for the kind offer. I'll order a new core temp sensor and fit that. I'm getting very quick at getting the dash trim apart these days!