A/C Signal Circuit Troubleshooting
NOTE:
  • Use this troubleshooting procedure if the A/C compressor, the A/C condenser fan, and the radiator fan are inoperative.
  • Before doing any symptom troubleshooting, check for powertrain DTCs.
  1. Connect the HDS to the DLC.
  1. Start the engine.
  1. Turn on the A/C on the climate control unit.
  1. Check the A/C SWITCH in the PGM-FI Data List with the HDS.
Is the A/C SWITCH on?
YES -
The A/C signal is OK at this time.■
NO -
Go to Step 5 .
  1. Turn the ignition switch OFF.
  1. Disconnect the climate control unit 32P connector.
  1. Measure the evaporator temperature sensor resistance between the climate control unit 32P connector terminals No. 23 and No. 24.
Is the resistance less than 24 kΩ?
YES -
Go to Step 8 .
NO -
  1. Reconnect the climate control unit 32P connector.
  1. Turn the ignition switch ON (II).
  1. Check the blower motor operates at all speeds.
Does the blower motor operate at all speeds?
YES -
Go to Step 11 .
NO -
Repair the problem in the blower motor circuit.■
  1. Turn the ignition switch OFF.
  1. Disconnect the climate control unit 32P connector.
  1. Turn the ignition switch ON (II).
  1. Measure the voltage between the climate control unit 32P connector terminal No. 20 and body ground.
Is there battery voltage?
YES -
Go to Step 15 .
NO -
Repair open in the wire between the climate control unit and the MICU.■
  1. Turn the ignition switch OFF.
  1. Reconnect the climate control unit 32P connector.
  1. Set the A/C button and fan control switch ON, then turn the ignition switch ON (II).
  1. Measure the voltage between the climate control unit 32P connector terminal No. 20 and body ground.
Is there 0.5 V or less?
YES -
NO -
Check for loose wires or poor connections at the climate control unit 32P 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 .■