Dodge Nitro. Manual — part 518

REMOVAL-3.7L

Fig. 45: Identifying Power Cord, Block Heater & Core Hole
Courtesy of CHRYSLER LLC

1. Drain cooling system. See STANDARD PROCEDURE.

2. Raise vehicle on hoist.

3. Detach power cord plug from heater.

1 - POWER CORD
2 - BLOCK HEATER
3 - CORE HOLE

2007 Dodge Nitro R/T

2007 ENGINE Cooling - Nitro

4. Loosen screw in center of heater. Remove heater assembly.

INSTALLATION

INSTALLATION-3.7L

Fig. 46: Identifying Power Cord, Block Heater & Core Hole
Courtesy of CHRYSLER LLC

1 - POWER CORD
2 - BLOCK HEATER
3 - CORE HOLE

2007 Dodge Nitro R/T

2007 ENGINE Cooling - Nitro

1. Thoroughly clean core hole and heater seat.

2. Insert heater assembly (2) with element loop positioned upward .

3. With heater seated, tighten center screw securely to assure a positive seal.

4. Connect power cord to heater.

5. Lower vehicle.

6. Fill cooling system. See STANDARD PROCEDURE.

SENSOR-ENGINE COOLANT TEMPERATURE

DESCRIPTION

DESCRIPTION

The Engine Coolant Temperature (ECT) sensor is used to sense engine coolant temperature. The sensor
protrudes into an engine water jacket.

The ECT sensor is a two-wire Negative Thermal Coefficient (NTC) sensor. Meaning, as engine coolant
temperature increases, resistance (voltage) in the sensor decreases. As temperature decreases, resistance
(voltage) in the sensor increases.

OPERATION

OPERATION

At key-on, the Powertrain Control Module (PCM) sends out a regulated 5 volt signal to the ECT sensor. The
PCM then monitors the signal as it passes through the ECT sensor to the sensor ground (sensor return).

When the engine is cold, the PCM will operate in Open Loop cycle. It will demand slightly richer air-fuel
mixtures and higher idle speeds. This is done until normal operating temperatures are reached.

The PCM uses inputs from the ECT sensor for the following calculations:

For engine coolant temperature gauge operation through the bus communications

Injector pulse-width

Spark-advance curves

ASD relay shut-down times

Idle Air Control (IAC) motor key-on steps

Pulse-width prime-shot during cranking

O2 sensor closed loop times

CAUTION: To prevent damage, the power cord must be secured in its retaining

clips, and not positioned so it could contact linkages or exhaust
manifold.

2007 Dodge Nitro R/T

2007 ENGINE Cooling - Nitro

Purge solenoid on/off times

EGR solenoid on/off times (if equipped)

Leak Detection Pump operation (if equipped)

Radiator fan relay on/off times (if equipped)

Target idle speed

REMOVAL

REMOVAL-3.7L ENGINE

Fig. 47: Removing/Installing MAP Sensor/ECT Sensor
Courtesy of CHRYSLER LLC

2007 Dodge Nitro R/T

2007 ENGINE Cooling - Nitro