92 LeSabre A/C auto activation Logic
shtlcdr
10-04-2005, 07:11 PM
R134 Conversion - on recent LeSabre purchase.http://www.automotiveforums.com/vbulletin/images/smilies/naughty.gif
Spent several hours Sat morning doing diagnostics on compressor control system. PCM Enable LOW on the Gn/Bk line to relay fails to operate. {Can force line low (ground) and system works well(Blows Cold) Have shorted/opened sensors on compressor & freon high/low lines to 'complete' circuits to get 'auto' mode... But still fails.http://www.automotiveforums.com/vbulletin/images/smilies/sly.gif
Entered clear mode and reset any that were set by my 'tampering'. Just can't get rid of code 66 (Freon Low) Removed inspected/cleaned ALL associated connectors/wires/contacts to include Control head and PCM connectors. Opened PCM to inspect for burned /failed switchers. When all went back together it worked fine for one trip to and from work cycling appropriately. But failed on next use.
http://www.automotiveforums.com/vbulletin/images/smilies/banghead.gif
Pressures in system are 'acceptable' for r134 operation and worked well for about a week. Beginning to believe one of the sensors is 'resistive' and is 'comparing' pressure.(leaking?)(threshold value?) But I don't know where that one is. I metered all snapswitches as open/closed assuming the OPENS would short at specific pressure.(inverse for CLOSED)(unvalidated transition pressure)
I really need to 'discover' the "Proper Operation Logic" that the control system & PCM requires to work auto mode. Would like truth table or diagram/description of the Control unit descrete sensor lines and their proper values for 'AUTO' operation. Anybody been here?http://www.automotiveforums.com/vbulletin/images/smilies/smokin.gif
-Need More input!-
Spent several hours Sat morning doing diagnostics on compressor control system. PCM Enable LOW on the Gn/Bk line to relay fails to operate. {Can force line low (ground) and system works well(Blows Cold) Have shorted/opened sensors on compressor & freon high/low lines to 'complete' circuits to get 'auto' mode... But still fails.http://www.automotiveforums.com/vbulletin/images/smilies/sly.gif
Entered clear mode and reset any that were set by my 'tampering'. Just can't get rid of code 66 (Freon Low) Removed inspected/cleaned ALL associated connectors/wires/contacts to include Control head and PCM connectors. Opened PCM to inspect for burned /failed switchers. When all went back together it worked fine for one trip to and from work cycling appropriately. But failed on next use.
http://www.automotiveforums.com/vbulletin/images/smilies/banghead.gif
Pressures in system are 'acceptable' for r134 operation and worked well for about a week. Beginning to believe one of the sensors is 'resistive' and is 'comparing' pressure.(leaking?)(threshold value?) But I don't know where that one is. I metered all snapswitches as open/closed assuming the OPENS would short at specific pressure.(inverse for CLOSED)(unvalidated transition pressure)
I really need to 'discover' the "Proper Operation Logic" that the control system & PCM requires to work auto mode. Would like truth table or diagram/description of the Control unit descrete sensor lines and their proper values for 'AUTO' operation. Anybody been here?http://www.automotiveforums.com/vbulletin/images/smilies/smokin.gif
-Need More input!-
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