With Automatic AC

CIRCUIT DESCRIPTION
The powertrain control module (PCM) or engine control module (ECM) monitors the high side refrigerant pressure via a A/C refrigerant pressure sensor. When the pressure is high the signal voltage is high. When the pressure is low the signal voltage is low. When pressure is too high the PCM will not allow the A/C compressor clutch to engage.

CONDITIONS FOR RUNNING THE DTC
The PCM/ECM detects an A/C request.

CONDITIONS FOR SETTING THE DTC
- The A/C refrigerant pressure sensor signal is less than 0.1 volts for 5 seconds.
- The A/C refrigerant pressure sensor signal is greater than 4.9 volts for 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
The malfunction indicator lamp (MIL) will not illuminate.

CONDITIONS FOR CLEARING THE DTC
- The DTC will become history if the PCM/ECM no longer detects a failure.
- The history DTC will clear after 40 fault-free ignition cycles.
- The DTC can be cleared with a scan tool.

DIAGNOSTIC AIDS
For an intermittent, refer to Diagnostic Aids for Circuit Testing and Wiring Repair Procedures.

TEST DESCRIPTION

Steps 1 - 2:

Steps 3 - 4:

Steps 5 - 8:

Steps 9 - 13:

Steps 14 - 16:

The numbers below refer to the step numbers on the diagnostic table.
3. Tests for the proper operation of the circuit in the low voltage range.
4. Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
5. Tests for a short to voltage in the 5-volt reference circuit.
6. Tests for a high resistance or an open in the low reference circuit.