Ford 2001 Ranger, Manual

Page: 318 / 1218

412-02-24 412-02-24 Heating and Ventilation
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST N: DTC B2516 BLOWER CONTROL CIRCUIT FAILURE
TEST STEP ACTION TO TAKE
If both DTC B2514 and
DTC B2515, GO to N3.
•
Do DTC B2514 Blower (Fan) Circuit Short to Vbat and/or DTC
No = GO to N5.
B2515 Heater Blower Relay Circuit Failure also occur?
N2 CHECK GROUND TO VARIABLE BLOWER CONTROLLER
(VBC)
•
With key OFF, disconnect VBC C1971 and measure the resistance Yes = REPLACE the VBC.
between pin 5 (BK wire) on VBC C1971 and ground. REFER to Section 412-04 .
•
Is the resistance less than 5 ohms?
No = REPAIR the BK wire.
N3 CHECK VARIABLE BLOWER CONTROLLER (VBC) FEEDBACK
CIRCUIT FOR SHORT TO POWER
•
With key OFF, disconnect VBC C1971. Yes = GO to N4.
•
With key ON, measure the voltage between pin 1 (Y/R wire) on VBC No = System OK. CHECK wiring
C1971 and ground. for intermittent connections.
•
Is the voltage greater than 0 volts?
N4 CHECK CIRCUIT 148 (Y/R) FOR SHORT TO POWER
•
Connect 104-Pin Breakout Box (BOB) to IAA module C1945; leave IAA Yes = REPAIR the Y/R wire.
module disconnected.
•
With key ON, measure the voltage between BOB pin 64 and ground No = REPLACE the IAA module.
(BOB pin 80). REFER to Section 412-04 .
•
Is the voltage greater than 0 volts?
N5 CHECK BLOWER/FAN STATUS
•
With key ON, set the mode select knob to the PANEL/FLOOR position Yes = System OK. CHECK wiring
and monitor the IAA module PIDs BLOWER and BFSV while rotating for intermittent connections.
the blower control knob through all the blower speed positions and verify
the voltages below:
— LOW = 9.8-10.4 volts
— MED
1 = 6.8-7.4 volts
— MED 2 = 3.9-4.5 volts
— HIGH = 1.4-2.1 volts
•
Are the voltages correct?
No = GO to N6.
N6 CHECK CIRCUIT 515 (O/R) FOR OPEN
•
Connect 104-Pin Breakout Box (BOB) to interface adapter assembly Yes = GO to N7.
(IAA) module C1945; leave IAA module disconnected.
•
With key OFF, disconnect variable blower controller (VBC) C1971 and No = REPAIR the O/R wire.
measure the resistance of the O/R wire between pin 2 on VBC C1971
and BOB pin 5.
•
Is the resistance less than 5 ohms?
N7 CHECK CIRCUIT 515 (O/R) FOR SHORT TO GROUND
•
With key OFF, measure the resistance between BOB pin 5 and ground Yes = GO to N8.
(BOB pin 80).
•
Is the resistance greater than 10,000 ohms?
No = REPAIR the O/R wire.
N8 CHECK CIRCUIT 515 (O/R) FOR SHORT TO POWER
•
With key ON, measure the voltage between BOB pin 5 and ground Yes = REPAIR the O/R wire.
(BOB pin 80).
•
Is the voltage greater than 0 volts?
No = REPLACE the VBC.
REFER to Section 412-04 .
2001 Ranger EV, 01/2001