Engine light on and no heat on driver's side.

First, if you get heat on one side and not the other, the heater is working. The problem is related to what is called a blend air door. On vehicles with dual climate control, there are two blend doors. The door's function is to determine if you get heat or AC in the vehicle based on its position. Based on your description, one is not working. As a result, the actuator could be bad or it could be stuck. I hate to say it, but it is a major job to access. Most of the dashboard needs removed to access it. Eight hours sounds about right. Will that stop the vibration? I doubt it. However, the TCC is a concern for a vibration. The torque converter, if engaging OD too soon can cause it. The C1244 tells me the RPM's may be dropping too low and that can cause a vibration.

As far as the "gasket cover" has me confused. Are they refering to the valve cover gasket? Also, if you replace them, it would be an easier time to replace the plugs, but you don't have to. I don't know how many miles are on the vehicle or when they were last replaced, so it is hard to say if they should be replaced.

One last thing. The fact the engine doesn't warm up properly is setting other codes. If the t-stat was replaced, it still may be bad. The thermostat shouldn't fully open until 195°F. If it doesn't warm up, the t-stat is opening too soon and staying open. Otherwise, the engine would heat up. Pay attention to the cooling fans. Make sure they are not turning on. They shouldn't turn on until aprox 215°F. If they turn on, they will cause the engine to cool down quicker.

The passenger side blows warm air however the driver side blows cold air.
Could help me please

the heat in that vehicle is controlled by a blend door that regulates heated air flow. it is operated by an electric motor/actuator. The problem can be that the actuator is stripped or inoperative or the door itself could be damaged. This is what needs to be determined by examining the actuator and see if it is responding to heat change commands or not.

Dear
I verified the door it works normally.
Thank you

Feel the 2 heater hoses coming into the firewall. If they are both hot to the touch, then the issue is definitely n the blend doors.

Dear
The blend doors works perfectly.
If I press the AC OFF I get warm air from the left side however the temperature isn't the same like the right side.
Best regards

My car does not seem to be throwing heat. The A/C system works, but when I turn the temp up if the A/C is on then it will be only cold air rather than temp adjusted. If the A/C is off, then all I get is luke warm air, regardless if it is 100 degrees outside or 50 degrees. Is there a simple fix for this, or will i have to replace the entire A/C and heater system?

V/r
Frigid to the Bone

I sounds like you may simply have a thermostat that is stuck open. What does the engine temperature read, lower than it should?

Thank you anyway
I disassembled the blend door it works perfectly.
I disconnected the battery for 1 hour I reconnected it, the problem is not solved. Once I pressed the AC OFF it gives warm air!....
Best regatds

Yea, that sounds about right. So how do i fix that?

Your vehicle has 2 blend doors.... have you checked to see if both heater hoses are hot?

Remove the upper and lower intake, and perform the following.

Engine Coolant Outlet Pipe Replacement
Tools Required
J 38185 Hose Clamp Pliers

Removal Procedure
Drain the cooling system. Refer to Cooling System Draining and Filling .



Position the J 38185 to the clamp in order to remove the radiator inlet hose (1) from the coolant outlet pipe.



Remove the bolt (2) securing the following to the cylinder head:
• The oil level indicator tube (4)

• The coolant outlet pipe (3)

• The engine front lift bracket (1)

Remove the coolant outlet pipe (3) from the thermostat housing.



Remove the O-ring seals from the coolant outlet pipe.
Discard the O-rings.

Installation Procedure




Lubricate 2 new O-ring seals with coolant.
Important: Ensure the O-rings are not twisted.

Install the new O-ring seals around the coolant outlet pipe grooves.



Insert the coolant outlet pipe (3) into the thermostat housing.
Notice: Refer to Fastener Notice in the Preface section.

Install the bolt (2) securing the following to the cylinder head:
• The oil level indicator tube (4)

• The coolant outlet pipe (3)

• The engine front lift bracket (1)

Tighten
Tighten the oil level indicator tube bolt to 20 N·m (15 lb ft).

Engine Coolant Thermostat Housing Replacement (LA3, LY9)
Removal Procedure
Remove the coolant outlet pipe. Refer to Engine Coolant Outlet Pipe Replacement .
Remove the intake manifold. Refer to Intake Manifold Replacement in Engine Mechanical-2.6L and 3.2L.



Remove the thermostat housing bolts (1).
Remove the thermostat housing (2) with thermostat, from the engine.
Remove and discard the seal ring.
Remove the thermostat from the thermostat housing. Refer to Engine Coolant Thermostat Replacement .
Installation Procedure
Install the thermostat into the thermostat housing. Refer to Engine Coolant Thermostat Replacement .



Install a new seal ring.
Position the thermostat housing (2) with thermostat, to the engine.
Notice: Refer to Fastener Notice in the Preface section.

Install the thermostat housing bolts (1).
Tighten
Tighten the thermostat housing bolts to 20 N·m (15 lb ft).

Install the intake manifold. Refer to Intake Manifold Replacement in Engine Mechanical-2.6L and 3.2L.
Install the coolant outlet pipe. Refer to Engine Coolant Outlet Pipe Replacement .

After having to replace the ECM and ABS modules on my 2006 CTS, the heater blows cold air and the defroster blows lukewarm air. The heater hoses are hot, and the thermostat is working fine (at least the water temperature is good). Wondering if maybe some kind of control valve, or maybe a setting in ECM?

Did you put used computers in ?

yes, they were used. The mechanic who installed took to the dealer to have flash programmed.

So the heat worked and defroster before replacing the computers?Also thats strange to have to replace two computers at the same time.

wasn't at same time...strange situation...ECM changed out, then had code for ABS...changing both worked...everything else fine. Someone had hooked up battery charger to battery while still in car :-(

Was the polarity correct when the charger was hooked up?Also did the heat work before the battery was charged?Has the ac computer been scanned for codes yet?

blow cold air on drivers side and heater works fine on passenger side. Eppp

check your actuators, generic pic enclosed.

polarity was correct.
Heat worked fine before modules changed out.
didn't even know there was an AC computer, so no it
has not been scanned. I assume this is something that has
to be scanned separately?

Yes you have a auto climate control correct?If so you would need a professional scan tool not a diyer scan tool or free auto parts scan.One that can read all the computers in your car.You might even need that scan tool to diagnose the problem.

OK..I have a friend that has one for his body shop. I will see if I can get him to scan. Thanks.

Your welcome keep me posted.

Driver side heater don't work passenger side works fine

check to see if it is getting power to operate the heater. the unit may be bad.

My 04 cts blows cold air on drivers side and warm air on passenger side

This is most often a symptom of an HVAC actuator, or blend door problem. It can also be caused by inadequate temperature or flow through the heater core. The first thing to do would be to scan for codes. A typical code reader is only going to give you OBD fault codes, you need a scan tool that is capable of accessing other modules.

when i have the heat on the passenger side heats up great but the Drivers side does not .Is there a simple fix as in maybe a vacuum line of a valve stuck? . It is duel heat separate for passenger and driver. Just a little strange one side heats up and the other side blows cold

try pulling your hvac fuse with your key on for 60 seconds it may reet the actuators otherwise you'll have to have it scanned to see if the driver side actuator is working which it doesn't sound like it is. see pic, first fuse is underhood others under reear seat.