Ford 2001 Ranger, Manual

Page: 305 / 1218

412-02-11 412-02-11 Heating and Ventilation
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST D: DTC B1254 AIR TEMPERATURE EXTERNAL SENSOR CIRCUIT FAILURE
TEST STEP ACTION TO TAKE
D2 CHECK CIRCUITS 3061 (LB/O) AND 3062 (BK/W) FOR OPEN(S)
•
Connect 104-Pin Breakout Box (BOB) to IAA module C1945; leave IAA Yes = GO to D3.
module disconnected.
•
With key OFF, measure the resistance of the LB/O wire between ambient No = REPAIR the wire(s) in
temperature sensor C1952 and BOB pin 96. question.
•
With key OFF, measure the resistance of the BK/W wire between in-car
temperature sensor C1952 and BOB pin 77.
•
Are the resistances less than 5 ohms?
D3 CHECK CIRCUIT 3061 (LB/O) FOR SHORT TO GROUND
•
With key OFF, measure the resistance between BOB pin 96 and ground Yes = GO to D4.
(BOB pin 80).
•
Is the resistance greater than 10,000 ohms?
No = REPAIR the LB/O wire.
D4 CHECK CIRCUIT 3061 (LB/O) FOR SHORT TO POWER
•
With key ON, measure the voltage between BOB pin 77 and ground Yes = REPAIR the LB/O wire.
(BOB pin 80).
•
Is the voltage greater than 0 volts?
No = REPLACE the IAA module.
REFER to Section 412-04 .
PINPOINT TEST E: DTC C1776 HEATER SYSTEM FAILURE
TEST STEP ACTION TO TAKE
E1 RETRIEVE CONTINUOUS DIAGNOSTIC TROUBLE CODES
(DTCs) FROM INTERFACE ADAPTER ASSEMBLY (IAA) MODULE
WHILE IN PANEL/FLOOR MODE
•
With key ON, set the mode select knob to the PANEL/FLOOR position Yes = REFER to Symptom Chart.
and the temperature control knob to the full warm position.
•
Wait approximately 45 seconds and retrieve continuous DTCs from the No = GO to E2.
IAA module.
•
Do any climate control DTCs occur along with DTC C1776 Heater
System Failure?
E2 CHECK STATUS OF POSITIVE TEMPERATURE COEFFICIENT
(PTC) HEATER CORES
NOTE: Turn the key to the OFF position and clear continuous IAA
Yes = GO to E11.
module DTCs before proceeding. If PIDs CORE A and CORE B
indicate RETRY and PIDs HTR CAR and HTR CBR indicate YES
after 45 seconds, wait approximately 4 minutes for the results. If
CORE A or CORE B does not indicate FAULT, cycle the ignition key
OFF/ON and repeat.
•
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
IAA module PIDs CORE A, CORE B, HTR CAR, and HTR CBR
for approximately 45 seconds.
•
Do CORE A and CORE B PIDs both indicate FAULT?
No = If only CORE A PID
indicates FAULT, GO to
E3.
If only CORE B PID
indicates FAULT, GO to
E7.
E3 CHECK PTC HEATER CORE A
•
Disconnect the 12-volt auxiliary battery negative cable. Yes = GO to E4.
(Continued)
2001 Ranger EV, 01/2001