00Corvette

I'm trying to recharge my AC system. The DIC shows no codes, haven't had this issue before.

Tried pulling fuse number 27 for a few minutes and no difference.

Any ideas as to why that light won't stay on, it stays on for about 3 seconds then shuts off...I'm sure the compressor is NOT running when the light is off and I can't recharge without the compressor running...

Thanks,

Donnie

99MALLETT396

What you need to do is vacuum the system 1st then charge. the reason is that the low and high pressure switches are not seeing any pressure so that's why the compressor is not coming on.

Bill Curlee

READ and POST the system DTCs. Without the DTCs, your going to spend LOTs of money that you do not need to spend!!!!

Here is how to read the DTCs..

READING YOUR Engine Diagnostic Codes



The Diagnostic Display Mode is entered with the following procedure:

1) Turn on the ignition but don't start the engine. NOTE! You can read the DTCs with the engine running and or driving down the road but it can distract you. BE careful! Some DTCs clear themselves when you turn the ignition OFF!

2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold OPTIONS
4) While holding OPTIONS, press FUEL four times within a 10-second period.


Initially, on-board diagnostics go into an Automatic Mode which 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. ( 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 kinds of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current C code indicates a malfunction is present and active 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 English/Metric (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 and hold the RESET button 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.
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. You can GOOGLE the DTC and also find information on it.




Here is very good site that explains the DTCs:


http://www.corvette-web-central.com/C5DTCcode.html


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



Make sure to include the H or C suffix!!

If you have LOTS of history DTC's, just clear them and then see what comes back when you attempt to run the AC/HVAC System.

Please post all those DTCs.If t=you have an electrical componet/electrical issue, all the recharging in the world wont help. Not saying its not low on charge,, just saying read and post the DTCs and find out what the system doesnt like to keep the compressor from running.

BC

00Corvette

BC,

Car is showing no codes. I'll try the evacuate, vacuum and re-charge with a new pressure switch

sesand

I'm having the same problem. Let me know what you find.

Vettmann17

You most likely need the system recharged with freon, easy fix.

sesand

Ran the DIC and found error code P1546. I checked the fuse and relay associated with this. The fuse looks good and I replaced the relay with a spare and it made no difference. I also noticed the external temp gauge is always off (its 85 right now and it reads 60). I unplugged the temp sensor and this has not fixed the problem. Any ideas before I take it to the dealer?

dmarkshark

The temp sensor is not going to read differently until you drive it a bit. If the AC is not staying on,its usually a good bet that you are low on freon, but there are other things as well. first thing though is to get a reading on your AC pressures.

lucky131969

That code tells you the PCM is enabling micro relay 34, but no voltage is detected on the clutch status circuit......which suggest that 12 volts is not getting to the clutch.

Did you check for 12 volts on the line/load side of minifuse 24? You can also try jumpering the relay socket contacts 30 & 87 (key on), and the clutch should engage.

Bill Curlee

Heres an early C5 schematic for ya. Dont know what year you have::

ZZ06

Im assuming in your attempt to run AC, you start your car, push the AC button (or mode button) and the light comes on for a few seconds and goes out. If you press it again is it flashing at you? I had this happen to mine the first summer i bought it. I shut the car off and tried again, i quickly ran out of the car to see if the clutch was turning on the compressor. Bingo! It would try for a few seconds and quit. R2 compressor, cleaned condensor and walla ICE cold AC again. Havent had issues since and this was 2 years ago.

old stingray

Even if you show no A.C. codes disconnect the -neg. battery cable for a few mins. then reconnect it the A.C.light should now stay on and will now take the charge.It works for me.

sesand

The "extra" relay I had been given by the previous owner of the car turned out to be bad as well. New relay fixed it. Good info!

GM may have skimped on electronics quality, but the A/C blows ice cold!