Pinpoint Test S: Incorrect/Erratic Function In AUTO Mode

Climate Control System

Pinpoint Tests

Pinpoint Test S: Incorrect/Erratic Function in AUTO Mode

Refer to Wiring Diagram Set 55, Automatic Climate Control System for schematic and connector information. Diagrams By Number

Normal Operation

Under normal operation, the in-vehicle air temperature sensor receives a ground and a 5-volt reference voltage from the HVAC module. To accurately monitor the cabin air temperature, the in-vehicle air temperature sensor uses an integral fan to draw cabin air to the sensor, inside the instrument panel. The fan is supplied voltage and ground.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- In-vehicle temperature sensor
- HVAC module

PINPOINT TEST S: INCORRECT/ERRATIC FUNCTION IN AUTO MODE

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S1 CHECK IN-VEHICLE TEMPERATURE SENSOR FAN OPERATION


- Ignition ON.
- Make sure the ambient air temperature is above 2°C (35°F).
- Select PANEL mode.
- Press the A/C button (indicator ON).
- Press the RECIRC button (indicator ON).
- Place a piece of tissue within 25 mm (1 in) of the in-vehicle temperature/humidity sensor opening.
- Is the tissue drawn to the sensor opening?

Yes
GO to S2.

No
GO to S3.

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S2 CHECK THE SENSOR RESISTANCE


- Ignition OFF.
- Disconnect: In-Vehicle Temperature Sensor C233 .
- Measure the resistance between the in-vehicle temperature sensor C233 terminals and compare to the table below.









- Is the resistance within the specified values for the temperatures?

Yes
GO to S5.

No
INSTALL a new in-vehicle temperature sensor. TEST the system for normal operation.

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S3 CHECK CIRCUIT CBP30 (YE/BU) FOR VOLTAGE


- Ignition ON.
- Measure the voltage between in-vehicle temperature sensor C233-3, circuit CBP30 (YE/BU), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to S4.

No
VERIFY Smart Junction Box (SJB) fuse 30 (5A) is OK. If OK, REPAIR circuit CBP30 (YE/BU) for an open. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. Diagrams By Number

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S4 CHECK CIRCUIT GD114 (BK/BU) FOR GROUND


- Ignition OFF.
- Measure the resistance between in-vehicle temperature sensor C233-2, circuit GD114 (BK/BU), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
INSTALL a new in-vehicle temperature sensor. TEST the system for normal operation.

No
REPAIR circuit GD114 (BK/BU) for an open. TEST the system for normal operation.

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S5 CHECK THE HVAC MODULE CONNECTION


- Inspect the HVAC module connectors for:

- corrosion.
- pushed-out terminals.
- damaged terminals.
- Connect and correctly seat all the HVAC module connectors.
- Clear the DTCs.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new HVAC module. REFER to Climate Control Service and Repair. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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