Pinpoint Test D: B105A:12, B105A:14, B1A61:11, B1A61;15, B1A69:12, B1A69:14, B1A69:92

Refer to Wiring Diagrams AUTOMATIC CLIMATE CONTROL SYSTEM for schematic and connector information.

Normal Operation and Fault Conditions

In-Vehicle Temperature and Humidity Sensor, REFER to: Climate Control System - Vehicles With: Electronic Manual Temperature Control (EMTC) - System Operation and Component Description .

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
HVAC B105A:12	Cabin Temperature Sensor Fan: Circuit Short To Battery	Module senses greater than expected voltage on the circuit for the cabin temperature sensor fan.
HVAC B105A:14	Cabin Temperature Sensor Fan: Circuit Short To Ground Or Open	Module senses less than expected voltage on the circuit for the cabin temperature sensor fan.
HVAC B1A61:11	Cabin Temperature Sensor: Circuit Short To Ground	Module senses lower than expected voltage on the temperature sensor feedback circuit, indicating a short to ground.
HVAC B1A61:15	Cabin Temperature Sensor: Circuit Short To Battery Or Open	Module senses unexpected voltage on the circuit for the cabin temperature sensor.
HVAC B1A69:12	Humidity Sensor: Circuit Short To Battery	Module senses greater than expected voltage on the circuit for the humidity sensor.
HVAC B1A69:14	Humidity Sensor: Circuit Short To Ground Or Open	Module senses a short to ground or an open for the humidity sensor.
HVAC B1A69:92	Humidity Sensor: Performance Or Incorrect Operation	Module senses the wrong humidity sensor value.

Possible Sources

Wiring, terminals or connectors
In-vehicle temperature and humidity sensor
HVAC control module

Visual Inspection and Pre-checks

Make sure the in-vehicle temperature and humidity sensor harness is not chaffed.
Make sure BCM fuse 2 (5A) is OK.

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.

D1 CHECK THE IN-VEHICLE TEMPERATURE AND HUMIDITY SENSOR CIRCUITS FOR A SHORT TO VOLTAGE

Ignition OFF.

Disconnect BCM fuse 2 (5A).

Disconnect in-vehicle temperature and humidity sensor C233.

Disconnect HVAC control module C228A.

Disconnect HVAC control module C228B.

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C233-1	Courtesy of FORD MOTOR COMPANY	Ground
C233-3	Courtesy of FORD MOTOR COMPANY	Ground
C233-4	Courtesy of FORD MOTOR COMPANY	Ground
C233-5	Courtesy of FORD MOTOR COMPANY	Ground
C233-6	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the circuit in question.

GO to D2

D2 CHECK THE IN-VEHICLE TEMPERATURE AND HUMIDITY SENSOR CIRCUITS FOR A SHORT TO GROUND

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C233-1	Courtesy of FORD MOTOR COMPANY	Ground
C233-3	Courtesy of FORD MOTOR COMPANY	Ground
C233-4	Courtesy of FORD MOTOR COMPANY	Ground
C233-5	Courtesy of FORD MOTOR COMPANY	Ground
C233-6	Courtesy of FORD MOTOR COMPANY	Ground

Are the resistances greater than 10, 000 ohms?

Yes

GO to D3

No	REPAIR the circuit in question.

D3 CHECK THE IN-VEHICLE TEMPERATURE AND HUMIDITY SENSOR CIRCUITS FOR AN OPEN CIRCUIT

Measure:

Positive Lead	Measurement / Action	Negative Lead
C233-1	Courtesy of FORD MOTOR COMPANY	BCM fuse 2 (5A)

Positive Lead	Measurement / Action	Negative Lead
C233-3	Courtesy of FORD MOTOR COMPANY	C228B-27
C233-4	Courtesy of FORD MOTOR COMPANY	C228B-29
C233-5	Courtesy of FORD MOTOR COMPANY	C228B-19

Positive Lead	Measurement / Action	Negative Lead
C233-6	Courtesy of FORD MOTOR COMPANY	C228A-26

Are the resistances less than 3 ohms?

Yes

GO to D4

No	REPAIR the circuit in question.

D4 CHECK THE IN-VEHICLE TEMPERATURE AND HUMIDITY SENSOR CIRCUITS FOR A SHORT TOGETHER

Measure:

Positive Lead	Measurement / Action	Negative Lead
C233-1	Courtesy of FORD MOTOR COMPANY	C233-3
C233-1	Courtesy of FORD MOTOR COMPANY	C233-4
C233-1	Courtesy of FORD MOTOR COMPANY	C233-5
C233-1	Courtesy of FORD MOTOR COMPANY	C233-6
C233-3	Courtesy of FORD MOTOR COMPANY	C233-4
C233-3	Courtesy of FORD MOTOR COMPANY	C233-5
C233-3	Courtesy of FORD MOTOR COMPANY	C233-6
C233-4	Courtesy of FORD MOTOR COMPANY	C233-5
C233-4	Courtesy of FORD MOTOR COMPANY	C233-6
C233-5	Courtesy of FORD MOTOR COMPANY	C233-6

Are the resistances greater than 10, 000 ohms?

Yes	INSTALL a new in-vehicle temperature and humidity sensor. Refer to the appropriate procedure in REMOVAL AND INSTALLATION . TEST the system for normal operation. If the concern is still present, GO to D5

No	REPAIR the circuits necessary.

D5 CHECK FOR CORRECT HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE OPERATION

Ignition OFF.

Disconnect and inspect all HVAC control module electrical connectors (if not previously disconnected).

Repair:
- corrosion (install new connector or terminal - clean module pins)
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary

Connect all HVAC control module electrical connectors. Make sure they seat and latch correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes

CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new HVAC control module. REFER to the appropriate REMOVAL AND INSTALLATION .

No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.