Operation CHARM: Car repair manuals for everyone.
Home >> Ford >> 1993 >> Bronco Full Size V8-351 5.8L >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> A/C Signal >> Description and Operation
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

A/C Signal: Description and Operation

PURPOSE
The A/C signal is an input to the Powertrain Control Module (PCM) which informs it that the A/C clutch has been energized. The PCM adjusts the idle speed and air/fuel mixture to compensate for the increased engine load.
OPERATION
With the A/C demand switch closed and both the cycling pressure switch and the high pressure cutout switch shut, battery voltage will be supplied to circuit ACC (10) informing the PCM the A/C clutch is energized.

RELATED DIAGNOSTIC TROUBLE CODES

DTC 539 - A/C request during self test procedure.

DTC 559 - A/C ON circuit failure.
pro multis · About Operation CHARM