HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS) > Diagnostic Procedure for Sensors

SUNLOAD SENSOR

TROUBLE SYMPTOM:

Sensor identifies that sunlight is at maximum. Then, A/C system is controlled to COOL side.

Sensor identifies that sunlight is at minimum. Then, A/C system is controlled to HOT side.

NOTE:

When the sunload sensor check is performed indoors or in the shade, it could be diagnosed as having an open circuit. Always check the sunload sensor with the sun shining on it.

WIRING DIAGRAM:

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1.CHECK POWER SUPPLY VOLTAGE FOR SUNLOAD SENSOR.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from sunload sensor.

3) Turn the ignition switch to ON.

4) Measure the power supply voltage for sunload sensor.

Connector & terminal

(i51) No. 2 (+) — No. 1 (−):

Is the voltage approx. 5 V?

2.CHECK HARNESS CONNECTOR BETWEEN AUTO A/C CONTROL MODULE AND SUNLOAD SENSOR.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from the auto A/C control module.

3) Measure the resistance of the harness between the auto A/C control module and sunload sensor.

Connector & terminal

(i51) No. 2 — (i88) No. 16:

Is the resistance less than 1 Ω?

Repair the harness between auto A/C control module and sunload sensor.

3.CHECK HARNESS CONNECTOR BETWEEN AUTO A/C CONTROL MODULE AND SUNLOAD SENSOR.

Measure the resistance of the harness between the auto A/C control module and sunload sensor.

Connector & terminal

(i51) No. 1 — (i88) No. 14:

Is the resistance less than 1 Ω?

Repair the harness between auto A/C control module and sunload sensor.

4.CHECK INPUT VOLTAGE FOR AUTO A/C CONTROL MODULE.

1) Connect the connectors of sunload sensor and auto A/C control module.

2) Turn the ignition switch to ON.

3) Measure the voltage between connector terminals of auto A/C control module.

Connector & terminal

(i88) No. 16 (+) — (i88) No. 14 (−):

Is the voltage within approximately 1.0 — 4.0 V?

Replace the sunload sensor.

5.CHECK POOR CONTACT.

Check poor contact of auto A/C control module connector.

Is there poor contact of connector?

Repair the connector.

Replace the auto A/C control module.