A/C Signal Circuit TroubleshootingNOTE:
- Do not use this troubleshooting procedure if any of the following items are operative; A/C condenser fan, radiator fan, A/C compressor. Refer to the symptom troubleshooting index.
- Before performing symptom troubleshooting, check for powertrain DTCs, except K20Z2 engine, K20Z2 engine.
|1.||Turn the ignition switch OFF.|
|2.||Disconnect the HVAC control unit 24P connector.|
|3.||Turn the ignition switch ON (II).|
|4.||Measure the voltage between the HVAC control unit 24P connector terminal No. 11 and body ground.|
Is there battery voltage?
YES - Go to 5.
NO - Repair open in the wire beyween the HVAC control unit and the MICU.n
|5.||Turn the ignition switch OFF.|
|6.||Measure the evaporator temperature sensor resistance between the HVAC control unit 24P connector terminals No. 2 and No. 13.|
Is the resistance less than 24k W?
YES - Go to 7.
|7.||Reconnect the HVAC control unit 24P connector.|
|8.||Turn the ignition switch ON (II).|
|9.||Check the blower motor operates at all speeds.|
Does the blower motor operate at all speeds?
YES - Check for loose wires or poor connections at the HVAC control unit 24P connector. If the connections are good, substitute a known-good HVAC control unit and recheck. If the sympton goes away, relace the original HVAC control unit.n
NO - Repair the problem in the blower motor circuit.n