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Hi All,
I have a 2011 Grand sport that has been giving me random problems, but the most persistent is the HVAC controls.
The module LCD screen reacts to all the buttons when i press them, but it doesn't actually change any settings. For example, The screen shows a lower fans setting when i press down, but the fan remains the same speed. Same with the recirc and mode. Temp changes fine and when pull the fuse or battery, the fan starts low and will allow me to increase it, but then won't go back down.
Codes it was throwing:
B0268
B0248
B0423
B0269
B0409
B0419
B0408
What I've tried so far:
New battery
Check fuses
Re-charge AC system
New blend door actuator
Swapped HVAC control module (no change - so looks like i have a spare module to sell now)
I have poured over the forum looking for clues and coming up short. Any ideas at all will help.
Thanks! Pic for attention
Was the module you swapped a good known one ??…what I would do is clear all those DTC’s and see what comes back and if the module is still malfunctioning.
Thank you for the reply.
Yes, the swapped module was tested and worked.
I will get the codes cleared. Are you saying stored codes may be causing the "new" module to act the exact same way as the old one?
There are some DTC’s that the ECM will disable that circuit until the code or codes are cleared…clear the DTC’s and see what happens…if no good let me know what comes back on the next ignition cycle and I’ll see what sets those codes and check the wiring diagram.
Mine had the same symptoms and almost identical codes.Ended up being a bad mode valve.It runs a calibration test and when the first fail appears i think it goes into some type of default.I could adjust the fan speed but once it was on the highest setting it wouldn't go back down until I did an ignition cycle.Do you hear any type of motor actuato noise when the car is not running?Mine would do this every time the BCM was woke up.
Did you end up replacing the mode valve? The below thread on it makes it seem like a seriously in depth repair. No, I do not hear any actuators moving, just a whole lot of relays.
Thanks C5 Diag. I will ask my local shop to clear and re-run codes (working on getting myself a scanner now) and then get back to you hopefully tomorrow..
Crossing my fingers it is not the blend door Jamieo mentioned below.
I did replace the mode valve myself.Kind of intimidating but I just took my time.You can replace it without removing the complete assembly from the car but the whole dash assembly will have to come out.Hopefully that isn't your problem but it kind of sounds like it.You can see if it is working by looking through the dash vents and see if the film is moving.
Thanks C5 Diag. I will ask my local shop to clear and re-run codes (working on getting myself a scanner now) and then get back to you hopefully tomorrow..
Crossing my fingers it is not the blend door Jamieo mentioned below.
Don't buy one of those cheap A$$ code readers...get a good aftermarket bidirectional scan tool from either Autel or Launch...they are less than $500.00 now…with a “code reader” you will not be able to look at data from the HVAC module.
These are screen shots on my 08 with blower motor, recirc, and mode switch info…counts are actually voltages…the command is the HVAC module sending a command to those 3 components…if no command it’s usually the module and if you see the command change the component is bad…I NEVER change a component unless I do a circuit integrity check cause if I change a part and it’s not fixed I eat the cost of the part…I find it hard to believe that the recirc, blower, and mode are all inop if it’s a known good HVAC module…WAS THE MODULE THE SAME PART NUMBER AS THE OLD ONE ??…and MOST shops are poor at diagnostics especially electrical issues…I’d go to an auto electric shop if this may be over your head…the shop should be checking the HVAC power and grounds and low reference (computer ground)circuits….all of these components use 12 volts to move the recirc and mode actuators….also circuits are “deactivated” for whatever module has the issue per the FSM…you’ll need to erase those codes. Blower motor - low speed Blower motor- high speed Recirc -off Recirc- on Mode switch- vent Mode switch - floor Mode switch- Bi-level
@C5 Diag Thank you. Yes, same exact part number for the module. I brought it to a shop and had them clear the codes and re-read them. Same codes coming up. I would agree, probably not all 3 components are bad. I will bring a screenshot of your directions and reference pics to the shop and ask them to perform detailed diagnosis. Unfortunately, they were the ones who said it is a bad module and to replace it. Not too confident they will be able to sort this out, so I may need to find another shop here in Tampa. Thanks for your help!
I did replace the mode valve myself.Kind of intimidating but I just took my time.You can replace it without removing the complete assembly from the car but the whole dash assembly will have to come out.Hopefully that isn't your problem but it kind of sounds like it.You can see if it is working by looking through the dash vents and see if the film is moving.
Hi, so you were able to remove the Mode assembly with out removing the HVAC box? I am kind of hoping that I can remove it with out all the drama of removing the entire box, that is a lot of added work, removing the dash is a job, never mind all the drama of draining the coolant and refrigerant.
I did replace the mode valve without removing the HVAC assembly.It really isn't that bad,just intimidating to take the complete dash out.The issue now seems to be finding a new mode valve.I don't know if a used one would be worth taking a chance on considering the work involved but it may be the only option.
HVAC Not Functioning Properly (Help!)
