Tring to fix my rear HVAC. Hot/Cold change over not happening
- Thread starter wade
- Start date
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ACDELCO, part # 1573506
---------- Post added at 04:49 AM ---------- Previous post was at 04:48 AM ----------
im 99.9% its the control module, even though the retarded site calls it a blower motor resistor.
The pic it shows is exactly what the control module looks like. Ill return it if no go
---------- Post added at 04:49 AM ---------- Previous post was at 04:48 AM ----------
im 99.9% its the control module, even though the retarded site calls it a blower motor resistor.
The pic it shows is exactly what the control module looks like. Ill return it if no go
Hi.
I've the same problem with the rear HVAC. Only blows cold and the hot/cold actuator is stuck in his very upper position. I already swapped the floor/ceiling actuator with the hot/cold actuator. Same issue. So i strongly guess it is the control modul.
Found this TSB for it:
--------------------------------------------------------------------------------
#06-01-39-015A: Unable to Control Rear HVAC Temperature or Modes, Intermittent Ticking Noise from Rear HVAC Actuators or Rear HVAC DTCs B0434 or B3764 (Replace Auxiliary HVAC Control Module) - (Jan 12, 2007)
Subject: Unable To Control Rear HVAC Temperature Or Modes, Intermittent Ticking Noise From Rear HVAC Actuators Or Rear HVAC DTCs B0434 Or B3764 (Replace Auxiliary HVAC Control Module)
Models: 2003-2006 Cadillac Escalade Models
2003-2006 Chevrolet Suburban, Tahoe
2003-2006 GMC Yukon Models
with Automatic Control HVAC System and Rear A/C (RPOs CJ2 and C69)
--------------------------------------------------------------------------------
This bulletin is being revised to correct one of the blower motor control module part numbers. Please discard Corporate Bulletin Number 06-01-39-015 (Section 01 -- HVAC).
--------------------------------------------------------------------------------
Condition
Some customers may comment on one or more of the following conditions:
• An intermittent ticking/clicking noise from the rear Heating, Ventilation and Air Conditioning (HVAC) system.
• Unable to control rear HVAC system temperature.
• Unable to change rear HVAC system modes.
Technicians may find that Diagnostic Trouble Codes (DTCs) B0434 and/or B3764 have been set.
Cause
These conditions may be caused by HVAC actuators that hunt for the correct position. This cycling may cause a clicking or ticking noise.
An overtravel of the HVAC system control doors may cause one or more of the above system conditions. If an overtravel occurs, a DTC will be set, and the door will go to a preset default position.
When a system door defaults, that door will stay at the default position until the DTC is cleared. Clearing the DTC will allow the door to operate properly until the overtravel condition reoccurs. The following table lists the DTCs that may have been set and the door that is associated with that code.
Overtravel DTC
System Door Affected
B0434
Auxiliary (rear) Air Temperature Actuator
B3764
Auxiliary (rear) Mode Actuator
Correction
Technicians are to replace the auxiliary (rear) HVAC control module with the part number listed in the table below. Refer to the Auxiliary Heater and Air Conditioning Control Module Replacement procedure in SI for more information. This module contains a new calibration to compensate for the actuator overtravel condition and the hunting/clicking noises. The new calibration effectively eliminates DTCs B0434 and B3764. The new control module also eliminates the default position of the doors associated with the DTC. The new control module will allow door travel from counts 0 to 255 without setting a DTC or defaulting the door.
The new auxiliary HVAC control module is compatible with either the first or second design blower motor control module. When using the new auxiliary HVAC control module, the customer may notice a slight increase in the rear blower motor speed (approximately 50 rpm) at a given setting, as compared to the blower motor speed at the same setting with the original HVAC control module. If the customer comments that the increase in blower speed at a given setting is objectionable, the blower motor control module may be replaced with the second design part listed below to correct the slight increase in speed.
The revised auxiliary HVAC control module should not be used unless one or both of the DTCs are set or one or more of the conditions listed above are present. The revised auxiliary HVAC control module will not correct any other DTC or Air Conditioning (A/C) performance concern.
Parts Information
Auxiliary HVAC Control Module Part Number
Description
Qty
15832319
Module Assembly-Auxiliary Heater & A/C Control
1
The blower motor control modules listed below should not be used unless the customer finds the change in blower speeds between the original and the new auxiliary HVAC control modules objectionable.
Blower Motor Control Modules Part Number
Part Description
Vehicle Application
Quantity
89024926
Module Assembly, Auxiliary Heater & A/C Control (Auxiliary Blower Motor Control Module) (Second Design)
Escalade, Tahoe, Yukon (vehicles with a short wheelbase)
1
89018849
Module Assembly, Auxiliary Heater & A/C Control (Auxiliary Blower Motor Control Module) (Second Design)
Escalade ESV, Suburban, Yukon XL (vehicles with a long wheelbase)
1
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation
Description
Labor Time
D0901
Module, HVAC Control-Auxiliary - Replace
Use Published Labor Operation Time
Add
With Third Row Seat
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
--------------------------------------------------------------
They advise to swap the control modul to the revised one with the part number #15832319. My CM what i got in right now is #15185966. I was hoping that the rockauto modul can fix this problem, although i haven't ordered it by now. I'm also curious about why rockauto is selling one modul with a bunch of different part numbers. Maybe it's vital to use the modul with the correct part number as mentioned above.
Have you tried to initiate the recalibration sequence after you installed the new modul?
1. Place the ignition switch to the OFF position.
2. Remove the HVAC/ECAS fuse for a minimum of 10 seconds.
3. Install the HVAC/ECAS fuse.
4. Start the vehicle.
5. Wait 40 seconds for the HVAC control module to self-calibrate.
I've the same problem with the rear HVAC. Only blows cold and the hot/cold actuator is stuck in his very upper position. I already swapped the floor/ceiling actuator with the hot/cold actuator. Same issue. So i strongly guess it is the control modul.
Found this TSB for it:
--------------------------------------------------------------------------------
#06-01-39-015A: Unable to Control Rear HVAC Temperature or Modes, Intermittent Ticking Noise from Rear HVAC Actuators or Rear HVAC DTCs B0434 or B3764 (Replace Auxiliary HVAC Control Module) - (Jan 12, 2007)
Subject: Unable To Control Rear HVAC Temperature Or Modes, Intermittent Ticking Noise From Rear HVAC Actuators Or Rear HVAC DTCs B0434 Or B3764 (Replace Auxiliary HVAC Control Module)
Models: 2003-2006 Cadillac Escalade Models
2003-2006 Chevrolet Suburban, Tahoe
2003-2006 GMC Yukon Models
with Automatic Control HVAC System and Rear A/C (RPOs CJ2 and C69)
--------------------------------------------------------------------------------
This bulletin is being revised to correct one of the blower motor control module part numbers. Please discard Corporate Bulletin Number 06-01-39-015 (Section 01 -- HVAC).
--------------------------------------------------------------------------------
Condition
Some customers may comment on one or more of the following conditions:
• An intermittent ticking/clicking noise from the rear Heating, Ventilation and Air Conditioning (HVAC) system.
• Unable to control rear HVAC system temperature.
• Unable to change rear HVAC system modes.
Technicians may find that Diagnostic Trouble Codes (DTCs) B0434 and/or B3764 have been set.
Cause
These conditions may be caused by HVAC actuators that hunt for the correct position. This cycling may cause a clicking or ticking noise.
An overtravel of the HVAC system control doors may cause one or more of the above system conditions. If an overtravel occurs, a DTC will be set, and the door will go to a preset default position.
When a system door defaults, that door will stay at the default position until the DTC is cleared. Clearing the DTC will allow the door to operate properly until the overtravel condition reoccurs. The following table lists the DTCs that may have been set and the door that is associated with that code.
Overtravel DTC
System Door Affected
B0434
Auxiliary (rear) Air Temperature Actuator
B3764
Auxiliary (rear) Mode Actuator
Correction
Technicians are to replace the auxiliary (rear) HVAC control module with the part number listed in the table below. Refer to the Auxiliary Heater and Air Conditioning Control Module Replacement procedure in SI for more information. This module contains a new calibration to compensate for the actuator overtravel condition and the hunting/clicking noises. The new calibration effectively eliminates DTCs B0434 and B3764. The new control module also eliminates the default position of the doors associated with the DTC. The new control module will allow door travel from counts 0 to 255 without setting a DTC or defaulting the door.
The new auxiliary HVAC control module is compatible with either the first or second design blower motor control module. When using the new auxiliary HVAC control module, the customer may notice a slight increase in the rear blower motor speed (approximately 50 rpm) at a given setting, as compared to the blower motor speed at the same setting with the original HVAC control module. If the customer comments that the increase in blower speed at a given setting is objectionable, the blower motor control module may be replaced with the second design part listed below to correct the slight increase in speed.
The revised auxiliary HVAC control module should not be used unless one or both of the DTCs are set or one or more of the conditions listed above are present. The revised auxiliary HVAC control module will not correct any other DTC or Air Conditioning (A/C) performance concern.
Parts Information
Auxiliary HVAC Control Module Part Number
Description
Qty
15832319
Module Assembly-Auxiliary Heater & A/C Control
1
The blower motor control modules listed below should not be used unless the customer finds the change in blower speeds between the original and the new auxiliary HVAC control modules objectionable.
Blower Motor Control Modules Part Number
Part Description
Vehicle Application
Quantity
89024926
Module Assembly, Auxiliary Heater & A/C Control (Auxiliary Blower Motor Control Module) (Second Design)
Escalade, Tahoe, Yukon (vehicles with a short wheelbase)
1
89018849
Module Assembly, Auxiliary Heater & A/C Control (Auxiliary Blower Motor Control Module) (Second Design)
Escalade ESV, Suburban, Yukon XL (vehicles with a long wheelbase)
1
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation
Description
Labor Time
D0901
Module, HVAC Control-Auxiliary - Replace
Use Published Labor Operation Time
Add
With Third Row Seat
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
--------------------------------------------------------------
They advise to swap the control modul to the revised one with the part number #15832319. My CM what i got in right now is #15185966. I was hoping that the rockauto modul can fix this problem, although i haven't ordered it by now. I'm also curious about why rockauto is selling one modul with a bunch of different part numbers. Maybe it's vital to use the modul with the correct part number as mentioned above.
Have you tried to initiate the recalibration sequence after you installed the new modul?
1. Place the ignition switch to the OFF position.
2. Remove the HVAC/ECAS fuse for a minimum of 10 seconds.
3. Install the HVAC/ECAS fuse.
4. Start the vehicle.
5. Wait 40 seconds for the HVAC control module to self-calibrate.
