( TF09E8HG10100012062FAAT00 )
A/C Pressure Switch Circuit Troubleshooting
NOTE:
  • If the blower motor does not run at all speeds, the A/C compressor will be inoperative. Run the self-diagnostic function, and check the DTC B1241. Before performing any other troubleshooting, repair the cause of the inoperative blower motor.
  • Do not use this troubleshooting procedure if any of the following items are operative; condenser fan, radiator fan, A/C compressor, or if the heater is inoperative. Refer to the symptom troubleshooting index.
  • Check the A/C high-side pressure.
  1. Turn the ignition switch to ON (II).
  1. Check if the blower motor operates at all speeds.
Does the blower motor operate at all speeds?
YES -
Go to Step 3 .
NO -
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the climate control unit 36P connector.
  1. Turn the ignition switch to ON (II).
  1. Measure the voltage between the climate control unit 36P connector No. 26 terminal and body ground.
Is there battery voltage?
YES -
Go to Step 14 .
NO -
Go to Step 7 .
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the A/C pressure switch 2P connector.
  1. Turn the ignition switch to ON (II).
  1. Measure the voltage between the A/C pressure switch 2P connector No. 2 terminal and body ground.
Is there battery voltage?
YES -
Go to Step 11 .
NO -
Repair open in the wire between the A/C pressure switch and the MICU. If the wire is OK, substitute a known-good MICU and recheck. If the symptom goes away, replace the original MICU .■
  1. Check for continuity between the No. 1 and No. 2 terminals of the A/C pressure switch.
Is there continuity?
YES -
Go to Step 12 .
NO -
Replace the A/C pressure switch .■
  1. Connect the A/C pressure switch 2P connector No. 2 terminal to body ground with a jumper wire.
Do the compressor and fans operate?
YES -
Go to Step 13 .
NO -
  1. Disconnect the jumper wire and A/C pressure switch 2P connector.
  1. Check for continuity between the climate control unit 36P connector No. 26 terminal and the A/C pressure switch 2P connector No. 1 terminal.
Is there continuity?
YES -
Check for loose wires or poor connections at the climate control unit 36P connector and at the A/C pressure switch 2P connector.■
NO -
Repair open in the wire between the climate control unit and A/C pressure switch.■
  1. Turn the ignition switch to LOCK (0).
  1. Jump the SCS line with the HDS.
    NOTE: This step must be done to protect the engine control module (ECM)/powertrain control module (PCM) from damage.
  1. Disconnect ECM/PCM connector A (49P).
  1. Measure the evaporator temperature sensor resistance between the climate control unit 36P connector No. 23 terminal and ECM/PCM connector A (49P) No. 10 terminal.
Is the resistance less than 24 kΩ?
YES -
Check for loose wires or poor connections at the climate control unit connectors. If the connections are good, substitute a known-good climate control unit and recheck. If the symptom goes away, replace the original climate control unit .■
NO -