A/C Pressure Switch Circuit Troubleshooting

NOTE: Do not use this troubleshooting procedure if the following items are operative; A/C condenser fan, radiator fan, A/C compressor, or if the heater is inoperative, Refer to the symptom troubleshooting index. Check for body DTCs in test mode A of the MICS. Are the any DTCs indicated?
YES | - | Do the appropriate troubleshooting for the DTC indicated.■
NO | - | Go to Step 2 .
Disconnect the A/C pressure switch 2P connector. Turn the ignition switch ON (II). Measure the voltage between the No. 1 terminal of the A/C pressure switch 2P connector and body ground. Is there 5 V or more?
YES | - | Go to Step 5 .
NO | - | Go to Step 14 .
Turn the ignition switch OFF. |

Check for continuity between the No. 1 and No. 2 terminals of the A/C pressure switch. Is there continuity?
YES | - | Go to Step 7 .
NO | - | Go to Step 15 .
Reconnect the A/C pressure switch 2P connector. Disconnect climate control unit connector A (22P). Turn the ignition switch ON (II). |

Measure the voltage between the No. 5 terminal of climate control unit connector A (22P) and body ground. Is there 5 V or more?
YES | - | Go to Step 11 .
NO | - | Repair open in the wire between the climate control unit and the A/C pressure switch.■
Turn the ignition switch OFF. |

Measure the resistance between the No. 14 and No. 15 terminals of climate control unit connector A (22P). Is the resistance less than 24 kΩ?
YES | - | Go to Step 13 .
NO | - | Repair cause of high resistance in the evaporator temperature circuit.■
Perform the A/C communication in the Self-Diagnostic Function to obtain the IS-BUS communication verification status. Is the communication OK?
YES | - | Check for loose wire or poor connections at climate control unit connector A (22P) and at the A/C pressure switch 2P connector. If the connections are good, substitute a known-good climate control unit and printed circuit board, and recheck. If the symptom/indication goes away, replace the original climate control unit and printed circuit board.■
NO | - | Check for loose wire or poor connections at climate control unit connector A (22P) and at the A/C pressure switch 2P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit .■

Measure the voltage between the No. 2 terminal of under-hood fuse/relay box connector H (14P) and body ground with the under-hood fuse/relay box connectors connected. Is there 5 V or more?
YES | - | Repair open in the wire between the under-hood fuse/relay box and the A/C pressure switch.■
NO | - | Check for loose or poor connections at the No. 2 terminal of the under-hood fuse/relay box. if the connections are OK, replace the under-hood fuse/relay box.■
Check for proper A/C system pressure. Is the pressure within specifications?
YES | - | Replace the A/C pressure switch.■
NO | - | Repair the A/C pressure problem.■