Pinpoint Test V : B1A61:15, B1A63:15 And B1A64:15: Notes
Diagnostic Overview
Diagnostics in this article assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in Service Information for information about these practices.
Refer to Automatic Climate Control System , for schematic and connector information.
Normal Operation and Fault Conditions
The in-vehicle temperature/humidity sensor receives a ground from the HVAC control 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 control 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 control module detects the change through the RH and LH feedback circuits.
The HVAC control module internally ties the in-vehicle temperature/humidity sensor and the LH and RH autolamp/sunload sensor feedback short to voltage diagnostics together. In the event any of the 3 feedback circuits are shorted to voltage all three DTCs set.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| B1A61:15 | Cabin Temperature Sensor Circuit Open: Circuit Short to Battery or Open | This CMDTC sets when the HVAC control module senses greater than 4.95 volts on the in-vehicle temperature sensor feedback circuit, indicating a short to voltage. |
| B1A63:15 | Right Solar Sensor: Circuit Short to Battery or Open | This CMDTC sets when the HVAC control module senses greater than 4.95 volts on the RH sunload sensor feedback circuit, indicating a short to voltage. |
| B1A64:15 | Left Solar Sensor: Circuit Short to Battery or Open | This CMDTC sets when the HVAC control module senses greater than 4.95 volts on the LH sunload sensor feedback circuit, indicating a short to voltage. |
Possible Sources
- Wiring, terminals or connectors
- HVAC control module
Visual Inspection and Diagnostic Pre-checks
- Make sure the in-vehicle temperature/humidity sensor harness is not chaffed.