Ford 2001 Ranger, Manual

Page: 306 / 1218

412-02-12 412-02-12 Heating and Ventilation
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST E: DTC C1776 HEATER SYSTEM FAILURE
TEST STEP ACTION TO TAKE
•
Remove the high-voltage power distribution box (HVPDB) cover. No = REPLACE the PTC heater
•
Disconnect PTC switching module high-voltage C1912 and measure the core.
resistance between the DB wire and DG wire on PTC switching module
C1912M.
•
Is the resistance between 65 and 140 ohms?
E4 CHECK PTC HEATER CORE A CONTROL SIGNAL
•
With key OFF, reconnect PTC switching module C1912. Yes = GO to E17.
•
Reinstall HVPDB cover. No = GO to E5.
•
Connect 104-Pin Breakout Box (BOB) to IAA module and IAA module
C1945.
•
Reconnect the 12-volt auxiliary battery negative cable.
•
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 PID CORE A.
•
Cycle the ignition key (if necessary) OFF/ON until the CORE A PID
indicates ON.
•
Measure the voltage between BOB pin 33 and ground (BOB pin 80).
•
Is the voltage greater than 2 volts?
E5 CHECK PTC HEATER CORE A CONTROL CIRCUIT FOR
SHORT TO GROUND
•
With key OFF, disconnect BOB from IAA module; leave BOB Yes = GO to E6.
connected to IAA module C1945.
•
With key OFF, measure the resistance between BOB pin 33 and ground No = REPLACE the IAA module.
(BOB pin 80). REFER to Section 412-04 .
•
Is the resistance less than 7,000 ohms?
E6 CHECK CIRCUIT 3260 (O/W) FOR SHORT TO GROUND
•
Reconnect the 12-volt auxiliary battery negative cable. Yes = REPLACE the PTC
switching module. REFER
to Section 412-04 .
•
With key OFF, disconnect PTC switching module C1999 and measure No = REPAIR the O/W wire.
the resistance between BOB pin 33 and ground (BOB pin 80).
•
Is the resistance greater than 10,000 ohms?
E7 CHECK PTC HEATER CORE B
•
Disconnect the 12-volt auxiliary battery negative cable. Yes = GO to E8.
•
Remove the high-voltage power distribution box (HVPDB) cover. No = REPLACE the PTC heater
•
Disconnect PTC switching module high-voltage C1912 and measure the core.
resistance between the R wire and W wire on PTC switching module
C1912M.
•
Is the resistance between 65 and 140 ohms?
E8 CHECK PTC HEATER CORE B CONTROL SIGNAL
•
With key OFF, reconnect PTC switching module C1912. Yes = GO to E17.
•
Reinstall HVPDB cover. No = GO to E9.
•
Connect 104-Pin Breakout Box (BOB) to IAA module and IAA module
C1945.
•
Reconnect the 12-volt auxiliary battery negative cable.
•
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 PID CORE B.
•
Cycle the ignition key (if necessary) OFF/ON until the CORE B PID
indicates ON.
•
Measure the voltage between BOB pin 34 and ground (BOB pin 80).
•
Is the voltage greater than 2 volts?
(Continued)
2001 Ranger EV, 01/2001