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Ford Ranger EV (2001 year). Manual - part 74

412-02-1

Heating and Ventilation

Manual Table of Contents

SECTION 412-02 Heating and Ventilation

VEHICLE APPLICATION:

Ranger EV

CONTENTS

PAGE

SPECIFICATIONS .......................................................................................

412-02-2

DESCRIPTION AND OPERATION

Heating/Defrosting ....................................................................................

412-02-2

Heating/Defrosting —Postal Ranger EV ...........................................................

412-02-2

DIAGNOSIS AND TESTING

Heating/Defrosting/Ventilation System .............................................................

412-02-3

Electrical Schematic ...............................................................................

412-02-5

Inspection and Verification ........................................................................

412-02-5

Pinpoint Tests .......................................................................................

412-02-7

Symptom Chart .....................................................................................

412-02-5

REMOVAL AND INSTALLATION

PTC Heater Core —Electric Ranger .............................................................

412-02-32

PTC Heater Core —Postal Ranger EV ..........................................................

412-02-36

412-02-2

Heating and Ventilation

SPECIFICATIONS

Torque Specifications

Description

Lb/In

Description

Lb/In

Positive Temperature

26.5

Evaporator Housing Nuts

35.5

Coefficient Heater Core Cover

Heater Plenum Retaining Nuts

35.5

Screws

High-Voltage Power

Reservoir Nuts and Bolts

Distribution Box Cover Screws

(Continued)

The PTC heater is located in the standard Ranger

DESCRIPTION AND OPERATION

heater core assembly located on the LH side of the

Heating/Defrosting

dash panel. High-voltage DC is fed to the PTC

A positive temperature coefficient (PTC) heater is

heater by the PTC switching module. The PTC

used to heat the passenger compartment and defrost

heater is equipped with an overtemperature sensor,

the windshield on the Electric Ranger. The PTC

and the air that is circulated through the heater is

heater uses a two-stage electrical resistance heater

filtered through an unique climate control filter to

that operates on high-voltage direct current (DC).

prevent possible ignition of dirt or dust build-up on

At temperatures above 4

C (40

F), the first stage of

the heater. The heater will maintain the passenger

the PTC heater will operate to heat the passenger

compartment at a maximum of 26.5

C (85

F) in

compartment. At temperatures below 4

(40

F), both

order to conserve traction battery power.

stages of the PTC heater will operate.

The Postal Ranger EV has an unique feature called

The PTC heater is located in the standard Ranger

a Pre-Heat Function. The pre-heat function allows

heater core location, and high-voltage DC is fed to

for heating/defrosting while the vehicle is in the

the PTC heater by the PTC switching module. The

KEY-OFF position to help conserve battery energy.

PTC heater is equipped with an overtemperature

This feature will operate when the vehicle is

sensor, and the air that is circulated through the

connected to the charging station and the outside

heater is filtered through an climate control filter to

temperature is 18

C (64

F) or below. The button for

prevent possible ignition of dirt or dust build-up on

pre-heat is located to the left of the heater controls,

the heater. The heater will maintain the passenger

above the recirculation button. To activate, push the

compartment at a maximum of 26.5

C (85

F) in

button once. Heating is limited to 30 minutes of

order to conserve traction battery power.

operation per activation. This function will
automatically default the temperature control to full
heat and set the fan speed. The fan speed is

Heating/Defrosting —Postal Ranger

dependent on the temperature inside the vehicle.

Direction of airflow can be controlled using the

A positive temperature coefficient (PTC) heater is

mode selector knob. While the pre-heat function is

used to heat the passenger compartment and defrost

on, the vehicle will be in recirculation mode. To

the windshield on the Postal Ranger EV. The PTC

turn the pre-heat off, disconnect the vehicle from

heater uses a two-stage electrical resistance heater

the charging station, put the vehicle in the KEY-ON

that operates on high-voltage direct current (DC).

position or wait until the 30 minutes have passed.

At temperatures above 4

C (40

F), the first stage of

the PTC heater will operate to heat the passenger
compartment. At temperatures below 4

(40

F), both

stages of the PTC heater will operate.

412-02-3

Heating and Ventilation

•

DTC B1254 Air Temperature External Sensor

DIAGNOSIS AND TESTING

Circuit Failure

Heating/Defrosting/Ventilation System

— The interface adapter assembly (IAA) module

Diagnostic Trouble Code (DTC) Definition

uses the ambient temperature sensor to

The following DTCs relate to the

monitor the temperature of the outside air. If

heating/defrosting/ventilation system:

the ambient temperature sensor reads less than
-40

C (-40

F) or greater than 90

C (194

•

DTC B1238 Over Temperature Fault

for 30 seconds, the IAA module sets DTC

— The positive temperature coefficient (PTC)

B1254 and assumes the temperature to be

switching module uses an overtemperature

215

C (419

F).

switch that is mounted on the heater plenum

•

DTC C1776 Heater System Failure

assembly to monitor the temperature of the

— The positive temperature coefficient (PTC)

PTC heater cores. The PTC overtemperature

heater core consists of two cores (A and B).

switch is a normally closed switch that opens

The PTC switching module drives core A,

when an overtemperature condition occurs.

core B or both core A and core B depending

The switch is set to open at 93

C-100

on ignition key cycling and temperature. The

(199

F-212

F). If the switch opens, the PTC

PTC switching module switches between core

switching module pulls the overtemperature

A and core B between ignition key cycling

fault line to the interface adapter assembly

and turns on both cores at low temperatures. If

(IAA) module low (0 volts), and the IAA

the core that is turned on by the PTC

module sets DTC B1238.

switching module is open or is in an

•

DTC B1249 Blend Door Failure

overcurrent condition, the PTC switching

— The interface adapter assembly (IAA) module

module must see a time of 45-60 seconds on

monitors the range of blend door position. The

the suspect heater core before a DTC code can

IAA module sets DTC B1249 if it detects the

be set. Afterwards, the PTC Switching Module

blend door is not moving for 30 seconds of

disables that core, switches to the other core,

applied voltage or senses the blend door

and pulls the interface adapter assembly (IAA)

feedback to be less than 0.15 volts or greater

module control line for the faulted core low (0

than 4.85 volts. The IAA module also sets

volts). The IAA module sets DTC C1776

DTC B1249 if the autocalibration routine of

when it detects either control line (core A or

the blend door operation sets the full warm

core B) low. It is possible to see an

position at less than three volts or the full cool

intermittent NO-HEAT condition on one core.

position at more than two volts.

•

DTC C1779 Blower Switch Failure

•

DTC B1250 Air Temperature Internal Sensor

— The interface adapter assembly (IAA) module

Circuit Failure

monitors the blower speed signals from the

— The interface adapter assembly (IAA) module

climate control blower switch. The IAA

uses the in-car temperature sensor to monitor

module sets DTC C1779 if it detects an

the temperature of the passenger compartment.

invalid combination of the blower speed inputs

If the in-car temperature sensor reads less than

for more than 30 seconds.

-40

C (-40

F) or greater than 90

C (194

for 30 seconds, the IAA module sets DTC
B1250 and assumes the temperature to be
25

C (77

F).

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

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).

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