Ford 2001 Ranger, Manual

Page: 303 / 1218

412-02-9 412-02-9 Heating and Ventilation
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST B: DTC B1249 BLEND DOOR FAILURE
TEST STEP ACTION TO TAKE
B3 CHECK CIRCUITS 245 (BR/LG), 246 (P), 436 (R/LG), 437 (Y/LG),
AND 438 (R/W) FOR OPEN(S)
•
Connect 104-Pin Breakout Box (BOB) to IAA module C1945; leave the Yes = GO to B4.
IAA module disconnected.
•
With key OFF, measure the resistance of the BR/LG wire between pin 7 No = REPAIR the wire(s) in
on blend door actuator C240 and BOB pin 6. question.
•
With key OFF, measure the resistance of the P wire between pin 8 on
blend door actuator C240 and BOB pin 7.
•
With key OFF, measure the resistance of the R/LG wire between pin 6
on blend door actuator C240 and BOB pin 85.
•
With key OFF, measure the resistance of the Y/LG wire between pin 1
on blend door actuator C240 and BOB pin 51.
•
With key OFF, measure the resistance of the R/W wire between pin 5 on
blend door actuator C240 and BOB pin 72.
•
Are the resistances less than 5 ohms?
B4 CHECK CIRCUITS 245 (BR/LG), 246 (P), 436 (R/LG), AND 437
(Y/LG) FOR SHORT(S) TO GROUND
•
With key OFF, measure the resistance between BOB pins 6, 7, 51, 85 Yes = GO to B5.
and ground (BOB pin 80).
•
Are the resistances greater than 10,000 ohms?
No = REPAIR the wire(s) in
question.
B5 CHECK RESISTANCE OF BLEND DOOR ACTUATOR
•
With key OFF, reconnect blend door actuator C240. Yes = REPLACE the IAA module.
•
With key OFF, connect the IAA module to BOB; leave BOB connected REFER to Section 412-04 .
to IAA module C1945.
NOTE: You must set the temperature control knob to the full warm
position before disconnecting the IAA module from the BOB. Failure to do
so will result in misdiagnosis of the blend door actuator.
•
With key ON, set the mode select knob to the PANEL/FLOOR position
and the temperature control knob to the full warm position, and monitor
the IAA module PID BLENDDR until it indicates approximately 90%.
•
With key OFF, disconnect the IAA module from BOB; leave BOB
connected to IAA module C1945.
•
With key OFF, measure the resistance between the indicated BOB pins
and verify the resistances below:
— BOB pins 51 and 85 = 250-1,500 ohms
— BOB pins 51 and 72 = 3,500-6,000 ohms
— BOB pins 72 and 85 = 5,000-7,000 ohms
•
Are the resistances OK?
No = REPLACE the blend door
actuator.
PINPOINT TEST C: DTC B1250 AIR TEMPERATURE INTERNAL SENSOR CIRCUIT FAILURE
TEST STEP ACTION TO TAKE
C1 CHECK IN-CAR TEMPERATURE SENSOR
•
Connect 104-Pin Breakout Box (BOB) to IAA module C1945; leave IAA Yes = REPLACE the IAA module.
module disconnected. REFER to Section 412-04 .
•
With key OFF, measure the resistance between BOB pins 49 and 79 and
compare the reading to the values below:
No = GO to C2.
Actual Temperature (Approximate)
— 0
°
C (32
°
F) = 91,000-100,700 ohms
(Continued)
2001 Ranger EV, 01/2001