Code 124, A/C Request Shorted

Code will set if Code 35 is not set, A/C compressor is not requested by HVAC serial data, voltage is present on A/C low pressure switch circuit for 20 seconds and engine speed is greater than 500 RPM for 20 seconds.

NOTE: Test numbers refer to numbers on diagnostic chart.

Determines if conditions to set code are present.
With A/C low pressure switch unplugged and ignition on, scan A/C request should display off.
With low pressure switch unplugged, there should be no voltage on the A/C high pressure switch circuit.
With HVAC unplugged there should be no voltage on terminal "A" of A/C low pressure switch.

Fig 1: Code 124 Schematic (4.0L) A/C Request Shorted

Fig 2: Code 124 Diagnostic Flow Chart (4.0L) A/C Request Shorted