Ford 2001 Ranger, Manual

Page: 311 / 1218

412-02-17 412-02-17 Heating and Ventilation
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST H: DTC B1857 CLIMATE CONTROL ON/OFF SWITCH FAILURE
TEST STEP ACTION TO TAKE
H4 CARRY OUT ON-DEMAND SELF-TEST IN PANEL/FLOOR
MODE
•
With key ON, set the mode select knob to the PANEL/FLOOR position Yes = GO to H11.
and carry out the on-demand self-test for the IAA module.
•
Does DTC B1857 Climate Control On/Off Switch Failure occur?
No = System OK. CHECK wiring
for intermittent connections.
H5 CHECK A/C PRESENT SIGNAL STATUS
•
With key ON, monitor IAA module PID AC PRST. Yes = GO to H8.
•
Does the AC PRST PID indicate YES?
No = GO to H6.
H6 CHECK A/C PRESENT SIGNAL FROM A/C INVERTER MOTOR
CONTROLLER (IMC)
•
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 pin 93 and ground No = GO to H7.
(BOB pin 80).
•
Is the resistance less than 5 ohms?
H7 CHECK CIRCUIT 3024 (DB/LG) FOR OPEN
•
With key OFF, measure the resistance of the DB/LG wire between pin 3 Yes = REPLACE the A/C IMC.
on A/C IMC C1947 and BOB pin 93. REFER to Section 412-03 .
•
Is the resistance less than 5 ohms?
No = REPAIR the DB/LG wire.
H8 CHECK MODE SELECT SWITCH
•
With key OFF, disconnect mode select switch C234. Yes = GO to H9.
•
Measure the resistance between terminals 1 and 2 on the mode select No = REPLACE the mode select
switch with the mode select knob in the A/C and MAX A/C positions. switch.
•
Are the resistances less than 5 ohms?
H9 CHECK GROUND TO MODE SELECT SWITCH
•
With key OFF, measure the resistance between pin 1 (BK wire) on mode Yes = GO to H10.
select switch C234 and ground.
•
Is the resistance less than 5 ohms?
No = REPAIR the BK wire.
H10 CHECK CIRCUIT 3055 (BR/LG) FOR OPEN
•
Connect 104-Pin Breakout Box (BOB) to interface adapter assembly Yes = REPLACE the IAA module.
(IAA) module C1945; leave IAA module disconnected. REFER to Section 412-04 .
•
With key OFF, measure the resistance of the BR/LG wire between pin 2 No = REPAIR the BR/LG wire.
on mode select switch C234 and BOB pin 59.
•
Is the resistance less than 5 ohms?
H11 CHECK RECIRCULATION VACUUM PRESSURE SENSOR
SIGNAL
•
Connect 104-Pin Breakout Box (BOB) to the IAA module and IAA Yes = GO to H18.
module C1945.
•
With key ON, set the mode select knob to the OFF position and measure No = If voltage is less than 0.25
the voltage between BOB pin 94 and ground. volts, GO to H12.
•
Is the voltage between 0.25 and 3 volts?
If voltage is greater than 3
volts, GO to H16.
H12 CHECK RECIRCULATION VACUUM PRESSURE SENSOR
VOLTAGE REFERENCE
•
With key ON, measure the voltage between BOB pin 103 and ground Yes = GO to H14.
(BOB pin 80).
•
Is the voltage greater than 4.5 volts?
No = GO to H13.
H13 CHECK CIRCUIT 3066 (O/Y) FOR SHORT TO GROUND
(Continued)
2001 Ranger EV, 01/2001