Hello everyone, I just purchased a 2002 C5 and the person i bought it from told me the A/C was fine, and he just replaced the environmental controller in the dash. Well the passenger side is blowing cool, but the drive side is not. Could this be an issue with the condenser, or the interior of the car? Thanks.

 

You should check your codes before proceeding. It might be an actuator-related problem, or simply that the system is a little low on refrigerant (since the side cold is the passenger's and not the other way around).

In any case, don't add refrigerant blindly.

Check both pressures to have an idea of how things are. Take a look at this Post. It has detailed instructions to check/add refrigerant.

-These are the CliffsNotes:

Check your pressures against the chart below (you'll need to determine ambient temperature and humidity first). Make sure you take your readings with:

• Engine @ 2000 rpm
• A/C in coldest setting
• Fan at maximum speed
• Both windows down
• Thermometer in center air vent

When adding refrigerant, pay attention to both pressures, otherwise you might end up with the high side sky-high trying to get the low side to the chart's value.

Let us know how it goes.

 

If it's blowing cold on 1 side only, that definitely sounds like an actuator issue. Check your HVAC codes, these things fail a lot. The driver's side can be accessed from under the dash. Takes under an hour if you know what you're doing. I'd recommend pulling the seat as well so you'll have extra room.

 

READING YOUR C5 Engine Diagnostic Trouble Codes (DTC)



This procedure should be carried out any time you experience a problem with your C5. Most inexpensive store bought aftermarket code readers will ONLY read power train DTC’s. Reading the DTC’s with the C5 built in code reader will allow you to read ALL the modules in the vehicle.



The Diagnostic Display Mode is entered with the following procedure:

1) Turn on the ignition but don't start the engine.

2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)

3) Press and hold the OPTIONS button

4) While holding OPTIONS, press FUEL button four times within a 10 -second period.



Initially, the on-board diagnostics go into an Automatic Mode which will cycle through each module and shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each module. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.



There are two types of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current code indicates a malfunction is present in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes. More likely it's an indication of an intermittent malfunction.



Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.



Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except E/M. Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.

To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press RESET To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.

NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles. There are a few body module DTC’s that if set will prevent the module from operating properly. Once the DTC is cleared, the module will return to full function. This is not true for power train DTCs.



If you have never read and cleared your codes, there will probably be a lot of old history DTCs. It is recommended that you clear your codes and see if any come back during a driving cycle. Those are the ones that you need to concentrate on diagnosing.



Once you have the codes, the next question is: What to do with the information?

First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5.



NOTE and a WARNING. You can read the DTCs while the engine is running. I pull mine up all the time while driving.

WARNING. Don’t become distracted while reading DTCs while your driving and cause an accident!!!!! Use common sense and drive safe.



These are some very good C5 Diagnostic Trouble Code (DTC) explanation web sites!!! They also explain how to read the DTCs



Here are some very good sites that explain what DTC mean:



http://www.gearchatter.com/viewtopic11755.php



http://www.obd-codes.com/trouble_cod...d-ii-codes.php



Make sure to include the H or C suffix when you post your DTCs!!



NOTE!!! Start the car and let it idle. Then take it for a drive and cause the problem to occur. When you return home pull the codes BEFORE you shut off the engine.


Do NOT discount the codes with the H following them. They can provide an audit trail for issues going on with the car. They ARE important in diagnosing problems.

Post ALL the codes that you pull with the engine running..........

Some codes go away WITHOUT setting an H code when you shut the engine off. I suspect you will have several codes that will show C or HC that do NOT show when the engine is turned off.

 

So it is an electric motor operation or vacuum?

 

Sounds more like the electric actuator to me.

 

I ran the diag, and also plugged in my reader. I found no codes, so I believe it to be internal. I also checked the A/C pressure Hi and low and it is also in the green.

 

I don't think the average code reader is going to see AC codes. If you hold (I think) Options, then press Fuel 4x, the dash will show you all of the engine and body codes. No reader required.

 

As mentioned above, you should check the codes using the built-in system. If there are indeed no codes for the a/c actuators, it might be that the system is a just a little low on refrigerant (again, since the side that is cold is the passenger's, and not the other way around).

I don't know what you used to check the a/c pressures, but you should use a set of manifold gauges to get a reliable reading. We are looking at specific numbers here, not just a wide and generic green range. If you don't have a set, you can get a free-loaner from an auto parts store.

For example, if your current conditions are 70% humidity at 80°F, using the table above your target numbers are:

• Low Pressure - 34
• High Pressure - 245
• Center Vent Temp - 58°F

Taken with (otherwise the readings will be different):

• Engine @ 2000 rpm
• A/C in coldest setting
• Fan at maximum speed
• Both windows down
• Thermometer in center air vent

 

Great thank you I will. I wanted to check the codes anyways to see how she is doing.