relay DODGE TOWN AND COUNTRY 2001 Service Manual

system control switch on the front heater-A/C control
is not in the Off position. The blower motor can only
be turned off by turning off the rear system at the
front heater-A/C control. The blower motor receives
battery current whenever the rear blower motor
relay is energized. The rear blower motor relay out-
put circuit is protected by a fuse in the Intelligent
Power Module (IPM) located in the engine compart-
ment near the battery. In the MTC system, the
blower motor speed is controlled by regulating the
path to ground through the blower control switch and
the blower motor resistor. In the ATC system, the
blower motor speed is controlled by an electronic
blower power module, which uses a pulse width mod-
ulated input from the ATC module and feedback from
the blower motor to regulate the blower motor
ground path it provides. The blower motor and wheel
are used to control the velocity of air moving through
the rear heater-A/C unit housing. The blower motor
controls the velocity of the air flowing through the
rear heater-A/C housing by spinning the blower
wheel within the housing at the selected speed or, in
the ATC system, at the selected or programmed
speed.
DIAGNOSIS AND TESTING - REAR BLOWER
MOTOR
BLOWER MOTOR INOPERATIVE
(1) Check the fuse (Fuse 12 - 25 ampere) in the
Intelligent Power Module (IPM). If OK, go to Step 2.
If not OK, repair the shorted circuit or component as
required and replace the faulty fuse.
(2) Turn the ignition switch to the On position. Be
certain that the rear heater-A/C control power is
turned on. Check for battery voltage at the fuse
(Fuse 12 - 25 ampere) in the IPM. If OK, go to Step
3. If not OK, proceed to diagnosis of the rear blower
motor relay. (Refer to 24 - HEATING & AIR CONDI-TIONING/CONTROLS - REAR/BLOWER MOTOR
RELAY - DIAGNOSIS AND TESTING).
(3) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the rear HVAC wire harness connector for
the rear blower motor resistor (Manual Temperature
Control) or the rear blower power module (Automatic
Temperature Control) from the resistor or module
connector receptacle. Reconnect the battery negative
cable. Turn the ignition switch to the On position. Be
certain that the rear heater-A/C control power is
turned on. Check for battery voltage at the fused
rear blower motor relay output circuit cavity of the
rear HVAC wire harness connector for the rear
blower motor resistor (MTC) or the rear blower
power module (ATC). If OK, go to Step 4. If not OK,
repair the open fused front blower motor relay output
circuit to the IPM as required.
(4) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the rear blower motor pigtail wire connec-
tor from the take out and connector of the rear
HVAC wire harness (MTC) or the connector recepta-
cle of the rear blower power module (ATC). Use
jumper wires to connect a battery and ground feeds
to the blower motor pigtail wire connector. The
blower motor should operate. If OK with MTC, pro-
ceed to diagnosis of the rear blower motor resistor.
(Refer to 24 - HEATING & AIR CONDITIONING/
CONTROLS - REAR/BLOWER MOTOR RESISTOR -
DIAGNOSIS AND TESTING). If OK with ATC, use a
DRBIII scan tool to diagnose the rear blower power
module. Refer to the appropriate diagnostic informa-
tion. If not OK with MTC or ATC, replace the faulty
rear blower motor.
BLOWER MOTOR NOISE OR VIBRATION
Refer to the Blower Motor Noise/Vibration Diagno-
sis chart (Fig. 4).
24 - 56 DISTRIBUTION - REARRS
BLOWER MOTOR (Continued)
ProCarManuals.com

²Vehicle Speed Sensor
²Engine Coolant Temperature Sensor
²Throttle Position Sensor
²Engine Controller Self Test Faults
²Cam or Crank Sensor
²Injector and Coil
²Idle Air Control Motor
²EVAP Electrical
²EGR Solenoid Electrical
²Intake Air Temperature
²5 Volt Feed
ConflictÐThe Task Manager does not run the
Oxygen Sensor Monitor if any of the following condi-
tions are present:
²A/C ON (A/C clutch cycling temporarily sus-
pends monitor)
²Purge flow in progress
²Ethanel content learn is takeng place and the
ethenal used once flag is set
SuspendÐThe Task Manager suspends maturing
a fault for the Oxygen Sensor Monitor if an of the fol-
lowing are present:
²Oxygen Sensor Heater Monitor, Priority 1
²Misfire Monitor, Priority 2
OXYGEN SENSOR HEATER MONITOR
DESCRIPTIONÐIf there is an oxygen sensor
(O2S) DTC as well as a O2S heater DTC, the O2S
fault MUST be repaired first. After the O2S fault is
repaired, verify that the heater circuit is operating
correctly.
The voltage readings taken from the O2S are very
temperature sensitive. The readings are not accurate
below 300ÉC. Heating of the O2S is done to allow the
engine controller to shift to closed loop control as
soon as possible. The heating element used to heat
the O2S must be tested to ensure that it is heating
the sensor properly.
The heater element itself is not tested. The sensor
output is used to test the heater by isolating the
effect of the heater element on the O2S output volt-
age from the other effects. The resistance is normally
between 100 ohms and 4.5 megaohms. When oxygen
sensor temperature increases, the resistance in the
internal circuit decreases. The PCM sends a 5 volts
biased signal through the oxygen sensors to ground
this monitoring circuit. As the temperature increases,
resistance decreases and the PCM detects a lower
voltage at the reference signal. Inversely, as the tem-
perature decreases, the resistance increases and the
PCM detects a higher voltage at the reference signal.
The O2S circuit is monitored for a drop in voltage.
OPERATIONÐThe Oxygen Sensor Heater Moni-
tor begins after the ignition has been turned OFF
and the O2 sensors have cooled. The PCM sends a 5
volt bias to the oxygen sensor every 1.6 seconds. ThePCM keeps it biased for 35 ms each time. As the sen-
sor cools down, the resistance increases and the PCM
reads the increase in voltage. Once voltage has
increased to a predetermined amount, higher than
when the test started, the oxygen sensor is cool
enough to test heater operation.
When the oxygen sensor is cool enough, the PCM
energizes the ASD relay. Voltage to the O2 sensor
begins to increase the temperature. As the sensor
temperature increases, the internal resistance
decreases. The PCM continues biasing the 5 volt sig-
nal to the sensor. Each time the signal is biased, the
PCM reads a voltage decrease. When the PCM
detects a voltage decrease of a predetermined value
for several biased pulses, the test passes.
The heater elements are tested each time the
engine is turned OFF if all the enabling conditions
are met. If the monitor fails, the PCM stores a
maturing fault and a Freeze Frame is entered. If two
consecutive tests fail, a DTC is stored. Because the
ignition is OFF, the MIL is illuminated at the begin-
ning of the next key cycle.
Enabling ConditionsÐThe following conditions
must be met for the PCM to run the oxygen sensor
heater test:
²Engine run time of at least 5.1 minutes
²Key OFF power down
²Battery voltage of at least 10 volts
²Sufficient Oxygen Sensor cool down
Pending ConditionsÐThere are not conditions or
situations that prompt conflict or suspension of test-
ing. The oxygen sensor heater test is not run pending
resolution of MIL illumination due to oxygen sensor
failure.
SuspendÐThere are no conditions which exist for
suspending the Heater Monitor.
CATALYST MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide.
Normal vehicle miles or engine misfire can cause a
catalyst to decay. A meltdown of the ceramic core can
cause a reduction of the exhaust passage. This can
increase vehicle emissions and deteriorate engine
performance, driveability and fuel economy.
The catalyst monitor uses dual oxygen sensors
(O2S's) to monitor the efficiency of the converter. The
dual O2S strategy is based on the fact that as a cat-
alyst deteriorates, its oxygen storage capacity and its
efficiency are both reduced. By monitoring the oxy-
gen storage capacity of a catalyst, its efficiency can
be indirectly calculated. The upstream O2S is used to
detect the amount of oxygen in the exhaust gas
before the gas enters the catalytic converter. The
RSEMISSIONS CONTROL25-3
EMISSIONS CONTROL (Continued)
ProCarManuals.com

Generic Scan Tool Code DRB IIITScan Tool Display
P0403 EGR Solenoid Circuit Open Circuit
EGR Solenoid Circuit Short Circuit
P0480 Fan 1 Control Circuit Open Circuit
Fan 1 Control Circuit Short Circuit
P0481 Fan 2 Control Circuit Open Circuit
Fan 2 Control Circuit Short Circuit
P0500 Vehicle Speed Sensor Frequency Too High
Vehicle Speed Sensor Frequency High Level Duration
Vehicle Speed Sensor Plausibility
Vehicle Speed Sensor Signal Voltage Too High
P0514 Battery Temperature Sensor Circuit Signal Voltage Too High
P0520 Oil Pressure Sensor Circuit MALF Signal Voltage Too High
Oil Pressure Sensor Circuit MALF Signal Voltage Too Low
Oil Pressure Sensor Circuit MALF Signal Voltage Too Low or High
P0530 A/C Pressure Sensor Circuit Plausibility
A/C Pressure Sensor Circuit Signal Voltage Too High
A/C Pressure Sensor Circuit Signal Voltage Too Low
A/C Pressure Sensor Circuit Supply Voltage Too High Or Low
P0560 System Voltage Too High
System Voltage Too Low
P0579 Speed Control Switch Signal Circuit Voltage Too High
Speed Control Switch Signal Circuit Voltage Too Low
P0606 ECM Error Gate Array - Communication
ECM Error Gate Array - Communication Not Verified
ECM Error Gate Array - Quantity Stop
ECM Error Gate Array - Has Occurred
ECM Error Redundant Overrun Monitoring
P0615 Starter Relay Circuit Open Circuit
Starter Relay Circuit Short Circuit
P0620 Generator Field Control MALF Open Circuit
Generator Field Control MALF Short Circuit
P0641 Sensor Reference Voltage A CKT Voltage Too High
Sensor Reference Voltage A CKT Voltage Too Low
P0645 A/C Clutch Relay Circuit Open Circuit
A/C Clutch Relay Circuit Short Circuit
P0651 Sensor Reference Voltage B CKT Voltage Too Low
Sensor Reference Voltage B CKT Voltage Too High
25a - 8 ON-BOARD DIAGNOSTICSRG
ON-BOARD DIAGNOSTICS (Continued)
ProCarManuals.com

Generic Scan Tool Code DRB IIITScan Tool Display
P0685 ECM/PCM Relay Control Circuit Shuts Off Too Early
ECM/PCM Relay Control Circuit Shuts Off Too Late
P0703 Brake Switch Signal Circuits Incorrect Can Message
Brake Switch Signal Circuits Plausibility With Redundant Contact
P1130 Fuel Rail Pressure Malfunction Small Leakage Detected
Fuel Rail Pressure Malfunction Small Leakage Detected
P1131 Fuel Pressure Solenoid Open Circuit
Fuel Pressure Solenoid Short Circuit
P1206 Calculated Injector Voltage #1 Too Low
Calculated Injector Voltage #2 Too Low
P1511 Battery Sense Line 1 Voltage Too High
Battery Sense Line 1 Voltage Too Low
P1601 Capacitor Voltage 1 Voltage Too High
Capacitor Voltage 1 Voltage Too Low
P1602 Capacitor Voltage 2 Voltage Too High
Capacitor Voltage 2 Voltage Too Low
P1605 Ignition Switch Plausibility
P1610 Voltage Regulator Signal Voltage Too High
Voltage Regulator Signal Voltage Too Low
P1680 EEPROM Plausibility Checksum Error
EEPROM Plausibility Code Word Incorrect Or Missing
EEPROM Plausibility Communication Error
EEPROM Plausibility Variation Number Error
EEPROM Plausibility VIN Checksum Error
EEPROM Plausibility VIN Write Error
P1685 SKIM System Invalid Key Code Received
SKIM System Invalid Secret Key In EEPROM
SKIM System Key Communication Timed Out
SKIM System SKIM Error
SKIM System Write Access To EEPROM Failure
P1696 EEPROM Communication Error
EEPROM Communication Not Verified
EEPROM Quanity Stop
EEPROM Recovery Occured
EEPROM Redundant Overrun Monitoring
RGON-BOARD DIAGNOSTICS25a-9
ON-BOARD DIAGNOSTICS (Continued)
ProCarManuals.com