Pinpoint Test G : B1B71:11 Or B1B71:15

WARNING: This page is about a different car, the 2017 Lincoln Navigator and 2017 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

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

G1 CHECK THE EVAPORATOR TEMPERATURE SENSOR RESISTANCE

Ignition OFF.

Disconnect: Evaporator temperature sensor C296.

Measure:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C296-1 component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C296-2 component side

Ambient Temperature	Resistance (Ohms)
-40 °C (-40 °F)	1, 005, 00-1, 104, 000
-20 °C (-4 °F)	287, 811-307, 800
0 °C (32 °F)	96, 890-101, 300
20 °C (68 °F)	37, 080-38, 000
25 °C (77 °F)	29, 700-30, 300
30 °C (86 °F)	23, 840-24, 430
35 °C (95 °F)	19, 260-19, 820
40 °C (104 °F)	15, 660-16, 180
60 °C (140 °F)	7, 239-7, 594
100 °C (212 °F)	1, 943-2, 091

Is the resistance within the specified values for the temperatures?

Yes	GO to G2.
No	INSTALL a new evaporator temperature sensor. REFER to Climate Control .

G2 CHECK THE HVAC CONTROL MODULE OUTPUT VOLTAGE

Ignition ON.

Select PANEL on the HVAC controls.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C296-1	Courtesy of FORD MOTOR COMPANY	C296-2

Is the voltage between 4.7 and 5.1 volts?

Yes	GO to G7.
No	GO to G3.

G3 CHECK THE EVAPORATOR TEMPERATURE SENSOR CIRCUITS FOR A SHORT TO VOLTAGE

Ignition OFF.

Disconnect: HVAC control module - EMTC C2357A.

Disconnect: HVAC control module - EATC C228A.

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C296-1	Courtesy of FORD MOTOR COMPANY	Ground
C296-2	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the circuit in question.
No	GO to G4.

G4 CHECK THE EVAPORATOR TEMPERATURE SENSOR CIRCUITS FOR A SHORT TO GROUND

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C296-1	Courtesy of FORD MOTOR COMPANY	Ground
C296-2	Courtesy of FORD MOTOR COMPANY	Ground

Are the resistances greater than 10, 000 ohms?

Yes	GO to G5.
No	REPAIR the circuit in question.

G5 CHECK THE EVAPORATOR TEMPERATURE SENSOR CIRCUITS FOR AN OPEN

For EATC vehicles, measure:

Positive Lead	Measurement / Action	Negative Lead
C296-1	Courtesy of FORD MOTOR COMPANY	C228A-19
C296-2	Courtesy of FORD MOTOR COMPANY	C228A-23

For EMTC vehicles, measure:

Positive Lead	Measurement / Action	Negative Lead
C296-1	Courtesy of FORD MOTOR COMPANY	C2357A-6
C296-2	Courtesy of FORD MOTOR COMPANY	C2357A-10

Are the resistances less than 3 ohms?

Yes	GO to G6.
No	REPAIR the circuit in question.

G6 CHECK THE EVAPORATOR TEMPERATURE SENSOR CIRCUITS FOR A SHORT TOGETHER

Measure:

Positive Lead	Measurement / Action	Negative Lead
C296-1	Courtesy of FORD MOTOR COMPANY	C296-2

Is the resistance greater than 10, 000 ohms?

Yes	GO to G7.
No	REPAIR the circuits.

G7 CHECK FOR CORRECT HVAC CONTROL MODULE OPERATION

Disconnect and inspect all HVAC control module connectors.

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

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

Operate the system and verify the concern is still present.

Is the concern still present?

Yes	CHECK OASIS for any applicable TSBs. If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no TSB addresses this concern, INSTALL a new HVAC control module. REFER to Climate Control .
No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.