Ford Electric Ranger 2001 Manual page 304

412-02-10
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST C: DTC B1250 AIR TEMPERATURE INTERNAL SENSOR CIRCUIT FAILURE
— 5 °C (41°F) = 71,100-78,700 ohms
— 10 °C (50°F) = 56,000-62,000 ohms
— 15 °C (59°F) = 44,400-49,100 ohms
— 20 °C (68°F) = 35,500-39,200 ohms
— 25 °C (77°F) = 28,500-31,500 ohms
— 30 °C (86°F) = 23,000-25,500 ohms
— 35 °C (95°F) = 18,700-20,700 ohms
— 40 °C (104°F) = 15,300-16,900 ohms
• Is the resistance OK?
C2 CHECK CIRCUITS 3050 (W/O) AND 3060 (GY/R) FOR OPEN(S)
• With key OFF, disconnect in-car temperature sensor C2997 and measure
the resistance of the W/O wire between in-car temperature sensor C2997
and BOB pin 49.
• With key OFF, measure the resistance of the GY/R wire between in-car
temperature sensor C2997 and BOB pin 79.
• Are the resistances less than 5 ohms?
C3 CHECK CIRCUIT 3050 (W/O) FOR SHORT TO GROUND
• With key OFF, measure the resistance between BOB pin 49 and ground
(BOB pin 80).
• Is the resistance greater than 10,000 ohms?
C4 CHECK CIRCUIT 3050 (W/O) FOR SHORT TO POWER
• With key ON, measure the voltage between BOB pin 49 and ground
(BOB pin 80).
• Is the voltage greater than 0 volts?
C5 CHECK ASPIRATOR INSTALLATION
• With key OFF, access the in-car temperature sensor behind the glove
compartment.
• Check for proper installation of in-car temperature sensor hose and
elbow.
• Is the aspirator installed correctly and the hose connected?
PINPOINT TEST D: DTC B1254 AIR TEMPERATURE EXTERNAL SENSOR CIRCUIT FAILURE
D1 CHECK AMBIENT TEMPERATURE SENSOR
• With key OFF, disconnect ambient temperature sensor C1952, measure
the resistance between the terminals of the ambient temperature sensor
and compare the reading to the values below:
Actual Temperature (Approximate)
— 0 °C (32°F) = 91,000-100,700 ohms
— 5 °C (41°F) = 71,100-78,700 ohms
— 10 °C (50°F) = 56,000-62,000 ohms
— 15 °C (59°F) = 44,400-49,100 ohms
— 20 °C (68°F) = 35,500-39,200 ohms
— 25 °C (77°F) = 28,500-31,500 ohms
— 30 °C (86°F) = 23,000-25,500 ohms
— 35 °C (95°F) = 18,700-20,700 ohms
— 40 °C (104°F) = 15,300-16,900 ohms
• Is the resistance OK?
(Continued)
Heating and Ventilation
TEST STEP
TEST STEP
ACTION TO TAKE
Yes = GO to C3.
No = REPAIR the wire(s) in
question.
GO to C4.
Yes =
No = REPAIR the W/O wire.
Yes = REPAIR the W/O wire.
No = GO to C5.
Yes = REPLACE the in-car
temperature sensor.
No = REPAIR as necessary.
ACTION TO TAKE
GO to D2.
Yes =
No = REPLACE the ambient
temperature sensor.
2001 Ranger EV, 01/2001
412-02-10