Ford 2001 Ranger, Manual

Page: 298 / 1218

412-02-4 412-02-4 Heating and Ventilation
DIAGNOSIS AND TESTING (Continued)
•
DTC C1780 Temperature Select Failure
•
DTC B2513 Blower (Fan) Circuit Failure
— The interface adapter assembly (IAA) module — The interface adapter assembly (IAA) module
monitors the temperature control signal from provides the pulse width modulation (PWM)
the climate control temperature control control signal to the variable blower controller
potentiometer. The IAA module sets DTC (VBC) and monitors the VBC feedback. The
C1780 if it detects the temperature command VBC contains an internal transistor relay that
to be greater than 4.95 volts or less than 0.05 is used to drive the blower motor at high
volts for more than 30 seconds. speed. The IAA module sets DTC B2513 if
the blower motor relay is closed, the VBC
•
DTC B1857 Climate Control On/Off Switch
internal relay is not closed or the VBC control
Failure
signal is greater than 1%, and the VBC
— The interface adapter assembly (IAA) module
feedback is less than 1 volt for more than 30
monitors the A/C present, system on, A/C on,
seconds. If DTC B2513 is set and the blower
and recirculation signals to determine if there
motor operates, the VBC has failed. If DTC
is a climate control on/off switch failure. The
B2513 is set and the blower motor does not
IAA module determines if the vehicle is
operate, but the coolant pump does, the blower
equipped with A/C by detecting an A/C
motor circuit has failed. If DTC B2513 is set
present signal from the A/C inverter motor
and the blower motor and coolant pump do
controller (IMC). The IAA module receives
not operate, the blower motor/coolant pump
the A/C on and system on signals from the
relay circuit has failed.
mode select switch and the recirculation signal
•
DTC B2514 Blower (Fan) Circuit Short to Vbat
from the fresh/recirculation select switch. The
IAA module sets DTC B1857 if it detects an
— The interface adapter assembly (IAA) module
invalid combination of the inputs for more provides the pulse width modulation (PWM)
than 45 seconds. control signal to the variable blower controller
(VBC) and monitors the VBC feedback. The
•
DTC U2015 Signal Link Fault (Non SCP)
IAA module sets DTC B2514 if the blower
— During the 5 seconds after receiving 12-volt
motor relay is open and the VBC feedback is
power from the interface adapter assembly
greater than the auxiliary battery voltage
(IAA) module, the positive temperature
minus 1 volt for more than 30 seconds.
coefficient (PTC) switching module carries out
•
DTC B2515 Heater Blower Relay Circuit Failure
a power on self test (POST) and outputs a 1.5
second-long pulse signal over the
— The interface adapter assembly (IAA) module
overtemperature fault line to the IAA module provides the pulse width modulation (PWM)
to indicate it passed the POST. If the IAA control signal to the variable blower controller
module does not receive this pulse, it will turn (VBC) and monitors the VBC feedback. The
off the 12-volt power for 0.5 seconds and VBC contains an internal transistor relay that
retry up to 3 times per ignition key cycle. If is used to drive the blower motor at high
all three attempts at powering the PTC speed. The IAA module sets DTC B2515 if
switching module fail, the IAA module the VBC internal transistor relay is closed and
assumes the PTC switching module failed its the VBC feedback is greater than 2 volts for
POST and sets DTC U2015. The IAA module more than 30 seconds.
also sets DTC U2015 if the PTC switching
module detects an internal short and pulls the
short fault line to the IAA module low (0
volts).
2001 Ranger EV, 01/2001