Ford Electric Ranger 2001 Manual page 305

412-02-11
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST D: DTC B1254 AIR TEMPERATURE EXTERNAL SENSOR CIRCUIT FAILURE
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 =
module disconnected.
• With key OFF, measure the resistance of the LB/O wire between ambient No =
temperature sensor C1952 and BOB pin 96.
• 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
(BOB pin 80).
• Is the resistance greater than 10,000 ohms?
D4 CHECK CIRCUIT 3061 (LB/O) FOR SHORT TO POWER
• With key ON, measure the voltage between BOB pin 77 and ground
(BOB pin 80).
• Is the voltage greater than 0 volts?
PINPOINT TEST E: DTC C1776 HEATER SYSTEM FAILURE
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
and the temperature control knob to the full warm position.
• Wait approximately 45 seconds and retrieve continuous DTCs from the
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
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?
E3 CHECK PTC HEATER CORE A
• Disconnect the 12-volt auxiliary battery negative cable.
(Continued)
Heating and Ventilation
TEST STEP
TEST STEP
ACTION TO TAKE
GO to D3.
REPAIR the wire(s) in
question.
GO to D4.
Yes =
No = REPAIR the LB/O wire.
Yes = REPAIR the LB/O wire.
No = REPLACE the IAA module.
REFER to Section
ACTION TO TAKE
Yes = REFER to Symptom Chart.
GO to E2.
No =
GO to E11.
Yes =
No = If only CORE A PID
indicates FAULT, GO to
E3.
If only CORE B PID
indicates FAULT, GO to
E7.
Yes = GO to E4.
2001 Ranger EV, 01/2001
412-02-11
412-04.