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Digital climate issues!

V

vncj96

New member
I have searched the forum with no luck to my particular problem. If the temp is set to 60 it blows the air at full fan speed as it should from any vent/defrost setting. As soon as I go to ANY higher degree setting the flow goes down to a trickle (even though fan speed speed is set to high) out of any vent/defrost. It will give hot air if that's what I set it to but considering its MN it would be nice to actually have a defroster that can get my windshield defrosted. It switches between vent and defrost just fine, control unit shot?
 


What does it do if you set it to 90 and press defrost? You don't defrost at 60F, 60 is only there for maximum AC. Which.. in MN this time of year, you would never want.

The actuators can take a moment to change, IIRC GM says change the temp and give it 45 seconds to move. What is the outside temperature reading on the display?
 
It moves just fine between vents and defrost it just has no velocity when the fan is set to hi, but if you leave the fan on hi and set the degrees to 60 the velocity of the air coming out is what it should be at. So basically at 60 degrees I have full velocity at ANY OTHER degree setting I have little air velocity.

Outside temp reads just fine and correctly, the other issue I have noticed is even if you shut HVAC off before shutting off the car it will sometimes be on when you start it back up. Also it never holds your setting if you leave the HVAC on before shutting off, it won't hold which mode you have it at, my guess the unit is shot.
 
http://www.grandprixforums.net/showthread.php?t=21941&highlight=change+blend+door+actuators follow this how to open up your car so you can see the 2 round vac pumps. car running work the controls watch the arm off the vac pump for it to move. you should be able to move it by hand if its not moving. MOVE IT CAREFULLY or it can break the plastic parts. id turn the car off if you try to move them by havd so theres no vacuum pulling on it.

the vac pump is shown in the first pic there, its the round part in the lower right. theres on one the pass side too, its in the same place. mirrored. they both need to be checked.
 
I'm inclined to agree that the HU seems to be shot on it. It should hold settings and 90 should do the same thing fan wise as 60 if the exterior temp is working properly.
 
As I was looking for another HVAC unit I came across something interesting. That if you hold down the driver and passenger button for 5 seconds it will enter a menu and give you trouble codes for the heating/coloring system? Also that if your little man flashes on the screen of the HVAC there is a problem. Cause my little dude randomly flashes.....
 


Here ya go:
On-Board Diagnosis Mode

The CJ2 air conditioning
is equipped with an on-board diagnostic feature which allows the Heater-A/C
control to detect certain system faults. The diagnostic feature may also be used
to display certain data parameters. If the heater-A/C control detects a fault in
the system, the man symbol will flash during the first 2 minutes of vehicle
operation.

Entry into the diagnostic mode is gained by pressing in on
both temperature knobs at the same time for 5 seconds. The following display
modes are found within diagnostics:

The diagnostic pointer
The diagnostic value
By rotating the driver temperature knob one detent in either
direction, the display is toggled between pointer and value. The value displayed
is the decimal equivalent of the RAM contents. A 2 is formed using the minus
sign and the leading 1 in order to display values over 199.

A diagnostic
pointer mode is identified by a minus sign preceding the pointer number. The
pointer provides an index, which identifies the corresponding diagnostic value.
The diagnostic Codes (DTCs) reside under diagnostic pointer -00. The pointer will be set to this
position upon initial entry into diagnostics. If more than one code exists, the
codes will be displayed sequentially at a rate of 2 seconds per fault. Rotating
the passenger temperature knob will switch the diagnostic pointers. A wrap
around feature is provided if the pointer is continued past either end. Other
data used by the computer resides under different diagnostic pointers, and may
not be of use in observing the system. Press any mode button in order to exit
the diagnostic mode.


Important
A 2-digit trouble code indicates
the fault is current. A 3-digit trouble code indicates a history
fault.


Clearing Codes
Press the A/C mode button in order to clear
codes from the heater-A/C control.

Any of the following components may
cause malfunction in the temperature controls:

The refrigerant
system
The electrical wiring
connections
The vacuum connections
Faulty components that have mechanical
problems, such as sticking valves
As a part of the diagnostic process inspect
the following components:

The refrigerant, vacuum or mechanical systems.
Refer to Vacuum Test .
The blower controls. Refer to 66-0 .
The compressor
controls. Refer to Cell 67: RPO L36, L67 .
The air delivery controls. Refer
to Power and Grounds .
The temperature
Refer to Electrical Diagnosis. Complete the diagnostic procedure for the heater
A/C control microprocessor.


Make sure to turn the climate control off
first, then hit both buttons at the exact same time. I know one time it took it
like 5 seconds, the next time it took like 15.Then rotate the left knob until
the desired number appears.

Position Description
-00 Error codes Click
here for the Trouble Codes chart
-01 (servo position) 103-107 43-162
-02 (servo position) 128 120-202
-03 (servo position) 150 162-194
-04 CJ2 Fan Speed Low=15, 29, 44, 58, 71, 86, 110=High, CJ2 Unit will
adjust to other increments as needed
-05 (servo position) 93 88-191
-06
(servo position) -152 00-252
-07 (servo position) 00 0, 34-255
-08 (servo
position) -155 00-255
-09 (servo position) 00 0, 23-255
-10 ? 04 04
-11
CJ2 Vent Mode 1=Def, 2=Bilevel, 3=Auto, 4=Lower, 5=Def+Lower
-12 Engine Temp -60 degrees 80=104, 95=131, 100=140 Peak@135°F
-13 Actual Vehicle Speed in MPH
-14 (servo position) 00 21=0
-15 ? 39 44
-16 Radiator low fan turn on temp -106 207
-17 Radiator low fan turn off temp 196 199
-18 ? 50 51
-19 (servo position) 162-169 40-172
-20 Affected by cabin temp sensor 89 50-172
-21 (servo position) 00 ?
-22 Sunload Sensor -117 LIGHT=126,
218=DARK
To return to normal operation, press the MODE button next to the
Passenger temperature knob.


This is a list of the Trouble Codes
displayed by the CJ2 Unit.
A two digit code indicates a current fault while a
three digit code indicates a historic fault.
Trouble Code Description
00
No System Fault
01 or 101 Inside Air Temperature
Short
02 or 102 Inside Air Temperature Sensor Open
03 or 103 Ambient
Outside Temperature Sensor Short
04 or 104 Ambient Outside Temerature Sensor
Open
05 or 105 LH Electric Actuator Open or Short
06 or 106 RH Electric
Actuator Open or Short
07 or 107 UART Serial Data Line Fault
08 or 108
Solar Sensor Open


and here, for a in depth fancy explanation of it all:
http://www.youtube.com/watch?v=uWAW7x5h9HI
 
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Also my temp gauge on the dash never gets above 160 in the winter, it does move but barely, this was the same on my other 3 GP in the winter, assume this is normal, can I switch my fan turn on temps at all? Or should I just do the cardboard in front of the radiator. Also the gauge does work as it got to where it should during the summer.
 
FFDP, what has yours reached during this cold snap we have had, will yours get up to 180-200 on a normal drive?
 


Weird, cuz every GP I have had ran cold in the winter, maybe I will start with that before I dig into the HVAC unit. My 3.1 sunbird ran at the 190 all day long hot or cold weather so I figured it was just a GP thing. Have owned a 2.8, 3.4 and this is my second 3.8.
 
Ok so more on my heat issue. today it was very warm here 40 degrees, and I sat inline at the carwash for 45 minutes and my car actually got up to operating temp. But even with the fan on high speed and it set to 90 it still doesn't have the velocity, but the fan is super loud like it should be for being on high. But if I drop it down to 60 degrees the velocity goes to what it should be. Is there a specific blend door that opens up to let hot air in? It changes from floor to vent to defrost as it should so for some reason its just not getting hot air from the heater core..........
 
Well both hoses are very hot from the heater core and considering my car temp got up today I guess I can rule out thermostat and plugged radiator, still not sure why my car runs so cold though.

Vacuum line looked in perfect condition, actually looks new. So it has to be the HU, vacuum lines at actuators or the actuators themselves.............
 
follow that how to. reach in put your finger on the white parts that spins, then work the controls. you'll feel it turn if its working.

you can also take one out, the pass side is super easy to get to, remove it, then turn the knob by hand, see if you get heat manually.

i went for a over a year with no actuators, just flipping them seasonally lol. yeah it sucked....
 


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