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post #6 of (permalink) Old 02-08-2011
SHELBY GT 350 Member
wmburns's Avatar
Joined: Sep 2010
Location: Houston
Posts: 6,849
Is your AC low on Freon?

The PCM maintains two idle trim settings. AC=on and AC=off. If the system is low on Freon (or the outside temperatures are very low), then the compressor will cycle on/off due to low suction pressure. The effect is the PCM can not re-learn a new AC=on idle trim value.

One possible solution is to temp jump the low pressure switch and allow the AC to run for a few minutes. The idle quality should improve once the new AC on values are re-learned.

2003 GT Convertible (sold & missed)
2000 GT coupe (Craigslist project. Fixed. Now my DD). Windsor to Romeo swap.
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