Pinpoint Test T: DTCs B1A61:15, B1A63:15 and B1A64:15

Climate Control System

Pinpoint Test T: DTCs B1A61:15, B1A63:15 and B1A64:15

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

Normal Operation

The in-vehicle temperature sensor receives a ground from the HVAC module. The sensor varies its resistance with the temperature. As the temperature rises, the resistance falls. As the temperature falls the resistance rises. The HVAC module measures this resistance to determine the temperature at the sensor. The autolamp/sunload sensor is grounded. As the light applied to the sensor changes, the HVAC module detects the change through the RH and LH feedback circuits.

The HVAC module internally ties the in-vehicle temperature sensor and the LH and RH autolamp/sunload sensor feedback short to voltage diagnostics together. in the event that any of the 3 feedback circuits are shorted to voltage all three DTCs will set.

- DTC B1A61:15 (Cabin Temperature Sensor: Circuit Short to Battery or Open)- The HVAC module senses greater than expected voltage on the sensor feedback circuit, indicating a short to voltage or an open circuit or sensor.

- DTC B1A63:15 (Right Solar Sensor: Circuit Short to Battery or Open)- The HVAC module senses greater than expected voltage on the RH sensor feedback circuit, indicating a short to voltage or an open circuit or sensor.

- DTC B1A64:15 (Left Solar Sensor: Circuit Short to Battery or Open)- The HVAC module senses greater than expected voltage on the LH sensor feedback circuit, indicating a short to voltage or an open circuit or sensor.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- HVAC module

PINPOINT TEST T : DTCs B1A61:15, B1A63:15 AND B1A64:15

T1 CHECK THE IN-VEHICLE TEMPERATURE SENSOR FEEDBACK CIRCUIT FOR A SHORT TO VOLTAGE

- Ignition OFF.

- Disconnect: HVAC Module- Dual Automatic Temperature Control (DATC) C228A.

- Disconnect: HVAC Module- DATC (Dual Automatic Temperature Control) C228B.

- Disconnect: In-Vehicle Temperature Sensor C233.

- Ignition ON.

- Measure the voltage between ground and:
- HVAC module- DATC (Dual Automatic Temperature Control) C228B-22, circuit VH417 (YE/OG), harness side.

- HVAC module- DATC (Dual Automatic Temperature Control) C228B-23, circuit VH416 (VT/GY), harness side.

- HVAC module- DATC (Dual Automatic Temperature Control) C228B-29, circuit VH414 (GN/BU), harness side.







Is any voltage present?

Yes
REPAIR circuit VH414 (GN/BU), VH416 (VT/GY) or for VH417 (YE/OG) a short to voltage. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No
GO to T2.

T2 CHECK THE HVAC MODULE CONNECTION

- Inspect the HVAC module component and harness side connectors for:
- corrosion

- damaged pins

- pushed-out terminals


- Connect and correctly seat all the HVAC module connectors.

- Clear the DTCs.

- Enter the following diagnostic mode on the scan tool: Self-Test- HVAC Module.

- Operate the system and verify the concern is still present.

Is the concern still present?

Yes
INSTALL a new HVAC module. 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. TEST the system for normal operation.