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

Tiny
NORE
  • MEMBER
  • 2003 CADILLAC CTS
  • 6 CYL
  • FWD
  • AUTOMATIC
Hello,

The engine light is on, I have no heat on the driver's side and the car is vibrating. I had it looked at by three different mechanics, all of which have not helped. I had the thermostat changed to a new one and the heat is still not working on the driver's side.

I was told the engine is heating up 50%, from what they said it is suppose to heat up at 95-100%

I had a diagnostic test and these were the codes: diagnosis because of engine trouble indicator light / diagnosis heating (left is not hot) test computer: Error Code P0128 Coolant Temp. Low/P0856 TCC torque req. Failed/C1277 signal/C1244 engine drag torque control controllscript Malfunction.

I was told the heating Valve has to be replaced in order to fix the heat in the drivers side and that may also stop the car from vibrating. They said to replace the valve it will take 8-10 hours of labor. Is this true?

They also told me the gasket cover is cracked, so now they have to replace all six sparkplugs, gasket and gasket cover. Is this accurate?

Please provide me with any opinions/advice you may have regarding my car.


Thanks in advance,
Nore
Do you
have the same problem?
Yes
No
Wednesday, March 2nd, 2011 AT 3:00 PM

30 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
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.
Was this
answer
helpful?
Yes
No
+2
Thursday, March 3rd, 2011 AT 6:14 PM
Tiny
RANYRIZK
  • MEMBER
  • 2003 CADILLAC CTS
  • 3.2L
  • V6
  • RWD
  • AUTOMATIC
  • 160,000 MILES
The passenger side blows warm air however the driver side blows cold air.
Could help me please
Was this
answer
helpful?
Yes
No
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
WRENCHTECH
  • EXPERT
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.
Was this
answer
helpful?
Yes
No
+1
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
RANYRIZK
  • MEMBER
Dear
I verified the door it works normally.
Thank you
Was this
answer
helpful?
Yes
No
+1
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
WRENCHTECH
  • EXPERT
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.
Was this
answer
helpful?
Yes
No
+1
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
RANYRIZK
  • MEMBER
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
Was this
answer
helpful?
Yes
No
+1
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
WOLVIEBURNS01
  • MEMBER
  • 2003 CADILLAC CTS
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 76,000 MILES
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
Was this
answer
helpful?
Yes
No
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
FACTORYJACK
  • EXPERT
I sounds like you may simply have a thermostat that is stuck open. What does the engine temperature read, lower than it should?
Was this
answer
helpful?
Yes
No
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
RANYRIZK
  • MEMBER
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
Was this
answer
helpful?
Yes
No
-1
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
WOLVIEBURNS01
  • MEMBER
Yea, that sounds about right. So how do I fix that?
Was this
answer
helpful?
Yes
No
-1
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
WRENCHTECH
  • EXPERT
Your vehicle has 2 blend doors. Have you checked to see if both heater hoses are hot?
Was this
answer
helpful?
Yes
No
+1
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
FACTORYJACK
  • EXPERT
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.
Was this
answer
helpful?
Yes
No
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
ALLENFROMCVILLE
  • MEMBER
  • 2006 CADILLAC CTS
  • 2.8L
  • V6
  • RWD
  • AUTOMATIC
  • 127,000 MILES
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?
Was this
answer
helpful?
Yes
No
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
SATURNTECH9
  • EXPERT
Did you put used computers in?
Was this
answer
helpful?
Yes
No
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
ALLENFROMCVILLE
  • MEMBER
Yes, they were used. The mechanic who installed took to the dealer to have flash programmed.
Was this
answer
helpful?
Yes
No
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
SATURNTECH9
  • EXPERT
So the heat worked and defroster before replacing the computers?Also thats strange to have to replace two computers at the same time.
Was this
answer
helpful?
Yes
No
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
ALLENFROMCVILLE
  • MEMBER
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 this
answer
helpful?
Yes
No
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
SATURNTECH9
  • EXPERT
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?
Was this
answer
helpful?
Yes
No
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
SCOTTR29
  • MEMBER
  • 2004 CADILLAC CTS
  • 78,000 MILES
Blow cold air on drivers side and heater works fine on passenger side. Eppp
Was this
answer
helpful?
Yes
No
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)
Tiny
HMAC300
  • EXPERT
Check your actuators, generic pic enclosed.
Was this
answer
helpful?
Yes
No
Tuesday, January 29th, 2019 AT 6:24 PM (Merged)

Please login or register to post a reply.

Recommended Guides