HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS) > Diagnostics for A/C System Malfunction > A/C OR SELF-DIAGNOSIS SYSTEMS DO NOT OPERATE

HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS) > Diagnostics for A/C System Malfunction

A/C OR SELF-DIAGNOSIS SYSTEMS DO NOT OPERATE

TROUBLE SYMPTOM:

• Switch LED fails, or switch does not operate.

• Self-diagnosis system does not operate.

WIRING DIAGRAM:

STEP	CHECK	YES	NO
1.CHECK FUSE. 1) Turn the ignition switch to OFF. 2) Remove the fuse No. 2 from main fuse box. 3) Check the condition of fuse.	Is the fuse blown out?	Replace the fuse.
2.CHECK FUSE. 1) Turn the ignition switch to OFF. 2) Remove the fuse No. 17 from fuse & relay box. 3) Check the condition of fuse.	Is the fuse blown out?	Replace the fuse.
3.CHECK AUTO A/C CONTROL MODULE POWER CIRCUIT. 1) Pull out the auto A/C control module connector. 2) Measure the voltage between auto A/C control module connector terminal and chassis ground after turning the ignition switch to OFF. Connector & terminal (i49) No. 4 (+) — Chassis ground (−):	Is the voltage 10 V or more?		Check open or short circuit of harness between auto A/C control module and fuse.
4.CHECK AUTO A/C CONTROL MODULE POWER CIRCUIT. Measure the voltage between auto A/C control module connector terminal and chassis ground after turning the ignition switch to the ON position. Connector & terminal (i49) No. 5 (+) — Chassis ground (−):	Is the voltage 10 V or more?		Check open or short circuit of harness between auto A/C control module and fuse.
5.CHECK AUTO A/C CONTROL MODULE GROUND CIRCUIT. Measure the resistance of harness between auto A/C control module and chassis ground. Connector & terminal (i49) No. 11 — Chassis ground:	Is the resistance less than 1 Ω?		Repair the harness for ground line.
6.CHECK POOR CONTACT. Check poor contact of auto A/C control module connector.	Is there poor contact in the connector?	Repair the connector.	Replace the auto A/C control module.