Dodge Nitro. Manual — part 636

circuits. The rear turn signal lamps include a clear bulb, a reflector and a red lens integral to each rear
lamp unit for domestic market vehicles, or an amber bulb and a clear lens for export market vehicles.

Other components of the exterior lighting system for this vehicle include:



Backup Lamp Switch - A plunger-type backup lamp switch is installed through the transmission housing
of vehicles equipped with a manual transmission and is actuated by the shifter mechanism within the
transmission when REVERSE gear is selected. On vehicles with an optional automatic transmission a
stand-alone Transmission Range Sensor (TRS) performs the backup lamp switch function.



Brake Lamp Switch - A plunger-type brake lamp switch is located on the brake pedal support bracket
under the instrument panel and is actuated by the brake pedal arm when the brake pedal is depressed.



Clockspring - The clockspring includes an integral turn signal cancel cam, which provides automatic
turn signal cancellation as the steering wheel is rotated back to its centered position following a vehicle
turning maneuver. The clockspring is located near the top of the steering column, directly beneath the
steering wheel. Refer to DESCRIPTION .



Hazard Switch - A latching push button-actuated hazard switch is integral to the switch pod located just
below the heater and air conditioner controls in the center stack area of the instrument panel.



Headlamp Leveling Switch - A four mode push button-actuated headlamp leveling switch is integral to
the switch pod located just below the heater and air conditioner controls in the center stack area of the
instrument panel of vehicles manufactured for certain markets where the headlamp leveling feature is
required.



Instrument Cluster - The Electro Mechanical Instrument Cluster (EMIC) is also known as the Cab
Compartment Node (CCN) in this vehicle. The EMIC/CCN is located in the instrument panel above the
steering column opening, directly in front of the driver. Refer to DESCRIPTION .



Instrument Panel Switch Pod - The instrument panel switch pod contains the hazard switch and, on
vehicles so equipped, the headlamp leveling switch. The switch pod is located just below the heater and
air conditioner controls in the center stack area of the instrument panel. Refer to DESCRIPTION .



Left Multi-Function Switch - The left (lighting) multi-function switch is located on the steering column,
just below the steering wheel. A control stalk that extends from the left side of the switch is used to select
the turn signal lamps (right or left) and to select the headlamp beam (low, high or optical horn). A control
knob on the control stalk is used to select the park lamps, headlamps or fog lamps.



Park Brake Switch - A park brake switch is located on the park brake lever mechanism on the floor
panel transmission tunnel between the two front seats.



Steering Control Module - The Steering Control Module (SCM) is located within the left multi-function
switch housing on the top of the steering column, just below the steering wheel. Refer to
DESCRIPTION .



Totally Integrated Power Module - The Totally Integrated Power Module (TIPM) is located in the
engine compartment, near the battery. Refer to DESCRIPTION .



Trailer Tow Wiring Adapter - Vehicles equipped with a factory-installed trailer towing package have a
wiring adapter provided that adapts the factory-installed heavy duty 7-way trailer tow connector to a
conventional 4-way light duty connector.



Trailer Tow Connector - Vehicles equipped with a factory-installed trailer towing package have a heavy
duty 7-way trailer tow connector installed in a bracket on the trailer hitch receiver.

2007 Dodge Nitro R/T

2007 ACCESSORIES AND EQUIPMENT Lamps/Lighting - Exterior - Service Information - Nitro

Hard wired circuitry connects the exterior lighting system components to the electrical system of the vehicle.
These hard wired circuits are integral to several wire harnesses, which are routed throughout the vehicle and
retained by many different methods. These circuits may be connected to each other, to the vehicle electrical
system and to the exterior lighting components through the use of a combination of soldered splices, splice
block connectors, and many different types of wire harness terminal connectors and insulators. Refer to the
appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector
repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for
the various wire harness connectors, splices and grounds.

OPERATION

LAMPS/LIGHTING - EXTERIOR

Following are paragraphs that briefly describe the operation of each of the major exterior lighting systems. The
lamps and the hard wired circuits between components related to the exterior lighting system may be diagnosed
using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness
routing and retention, connector pin-out information and location views for the various wire harness connectors,
splices and grounds.

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the exterior lighting
system or the electronic controls or communication between modules and other devices that provide some
features of the exterior lighting system. The most reliable, efficient, and accurate means to diagnose the exterior
lighting system or the electronic controls and communication related to exterior lighting system operation
requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

BACKUP LAMPS

The backup (or reverse) lamps have a path to ground at all times through a takeout and eyelet terminal of the
unibody wire harness that is secured by a nut to a ground stud on the body sheet metal within the passenger
compartment. On vehicles with a manual transmission, the backup lamp switch provides a hard wired input to
the Totally Integrated Power Module (TIPM) through a reverse switch signal circuit and the TIPM provides
battery voltage to the backup lamps on the backup lamp feed circuit whenever the ignition switch is not in the
LOCK position and the REVERSE position is selected with the transmission shift linkage.

On vehicles with an automatic transmission the Powertrain Control Module (PCM) or the Transmission Control
Module (TCM) monitors a multiplex input from the Transmission Range Sensor (TRS), then sends the proper
electronic transmission gear selector status messages to the TIPM over the Controller Area Network (CAN)
data bus. Whenever the ignition switch is not in the LOCK position and the TIPM receives an electronic
message indicating the status of the transmission gear selector is REVERSE, it provides a battery voltage output
through a high side driver to the backup lamps on the backup lamp feed circuit.

BRAKE LAMPS

The brake (or stop) lamps and the Center High Mounted Stop Lamp (CHMSL) each have a path to ground at all
times through a takeout and eyelet terminal of the body wire harness that is secured by a nut to a ground stud on
the body sheet metal within the passenger compartment. The CHMSL receives battery voltage directly on the
brake lamp switch output circuit when the brake lamp switch is closed by the brake pedal arm. The TIPM also

2007 Dodge Nitro R/T

2007 ACCESSORIES AND EQUIPMENT Lamps/Lighting - Exterior - Service Information - Nitro

receives battery voltage on the brake lamp switch output circuit, which it uses as a logic input to energize the
brake lamps. The TIPM provides battery voltage to the brake lamps through two high side drivers on the
tail/stop lamp rear feed circuit when it receives the proper input from the closed brake lamp switch.

DAYTIME RUNNING LAMPS

Vehicles manufactured for sale in Canada illuminate the high beam filament of both headlamp bulbs at a
reduced intensity when the engine is running, the parking brake is released, the headlamps are turned OFF, and
the optional automatic transmission gear selector lever is in any position except PARK. The park lamps may be
ON or OFF for DRL to operate. For vehicles with a manual transmission, the Daytime Running Lamps (DRL)
will operate in any transmission gear selector lever position. In fleet vehicles manufactured for the U. S. and
Mexican markets, DRL operates in the same manner, but the low beam filament of both headlamp bulbs is used
rather than the high beam filament. The TIPM must be programmed appropriately for this feature to be enabled.

Once enabled, anytime the TIPM receives electronic messages over the CAN data bus from the Powertrain
Control Module (PCM) indicating the engine is running, from the Electro Mechanical Instrument Cluster
(EMIC) (also known as the Cab Compartment Node/CCN) indicating the status of the left (lighting) multi-
function switch is in any position except headlamps ON and the parking brake lever is released, and from the
Powertrain Control Module (PCM) or the Transmission Control Module (TCM) indicating the automatic
transmission gear selector lever is in any position except PARK, the TIPM provides a pulse width modulated
voltage output to the headlamp high beam bulb filaments through high side drivers on the right and left high or
low beam feed circuits to produce illumination at a reduced intensity.

FRONT FOG LAMPS

The front fog lamps have a path to ground at all times through their connection to the engine compartment wire
harness. The engine compartment wire harness has takeouts with eyelet terminals that are secured by nuts to
ground studs on the front end sheet metal within the engine compartment. The Steering Control Module (SCM)
monitors a hard wired multiplex input from the left multi-function switch to determine whether the fog lamps
are selected, then sends an electronic front fog lamp switch status message to the EMIC over the Local
Interface Network (LIN) data bus and the EMIC relays an electronic front fog lamp request message to the
TIPM over the CAN data bus.

When the TIPM receives a front fog lamp request message it then controls front fog lamp operation by
controlling a battery voltage output through high side drivers on right and left fog lamp feed circuits. The TIPM
also sends the appropriate electronic message back to the EMIC to illuminate or extinguish the front fog lamp
indicator. In certain markets where required, the TIPM will automatically de-energize the front fog lamps any
time the headlamp high beams are selected.

The TIPM also provides a battery saver (load shedding) feature for the front fog lamps, which will turn these
lamps OFF if they are left ON for more than about eight minutes with the ignition switch in the LOCK position
or if there is a charging system failure.

Each front fog lamp includes an integral adjustment screw to be used for static aiming of the fog lamp beams.

HAZARD WARNING LAMPS

The hazard warning system includes the EMIC, the TIPM and the hazard switch in the switch pod located in the

2007 Dodge Nitro R/T

2007 ACCESSORIES AND EQUIPMENT Lamps/Lighting - Exterior - Service Information - Nitro

center stack area of the instrument panel, below the air conditioner and heater controls. The hazard switch
provides a hard wired input to the TIPM. When the TIPM receives an input from the hazard switch it controls
hazard warning system operation and flash rate by controlling battery voltage outputs through high side drivers
on the right and left turn signal feed circuits.

The TIPM also sends the appropriate electronic messages back to the EMIC over the CAN data bus to control
the illumination and flash rate of the right and left turn signal indicators, as well as to control the click rate of an
electromechanical relay soldered onto the EMIC electronic circuit board that emulates the sound emitted by a
conventional hazard warning flasher.

HEADLAMPS

The headlamp system includes the SCM, the EMIC, the TIPM, and the left (lighting) multi-function switch on
the steering column. The headlamp bulbs have a path to ground at all times through their connection to the
engine compartment wire harness. The engine compartment harness has takeouts with eyelet terminals that are
secured by nuts to ground studs on the front end sheet metal within the engine compartment. The TIPM will
store a Diagnostic Trouble Code (DTC) for any shorts or opens in the headlamp circuits.

The SCM monitors a hard wired multiplex input to determine the status of the left multi-function switch and
whether the headlamp high or low beams are selected. The SCM then sends the appropriate electronic
headlamp switch and headlamp beam select switch status messages to the EMIC over the LIN data bus. The
EMIC then sends the appropriate electronic headlamp request and headlamp beam request messages to the
TIPM over the CAN data bus. The TIPM responds to these messages by providing a pulse width modulated
voltage output to the headlamps through high side drivers on the right and left low and high beam feed circuits
to illuminate the selected headlamp filaments. The TIPM also sends the appropriate electronic messages to the
EMIC to control the illumination of the high beam indicator. When the optical horn feature is selected, the low
beams will shut OFF about 200 milliseconds after the high beams are activated.

The TIPM also remembers which beams (LOW or HIGH) were selected when the headlamps were last turned
OFF, and energizes those beams again the next time the headlamps are turned ON. The TIPM provides a battery
saver (load shedding) feature for the headlamps, which will turn these lamps OFF if they are left ON for more
than about eight minutes with the ignition switch in the LOCK position. The SCM and the EMIC each provide a
fail-safe feature for the headlamps, which will cause the TIPM to turn the low beam headlamps ON
automatically if there is no input available from the left multi-function switch. The TIPM also provides a fail-
safe feature for the headlamps that will turn the headlamps ON automatically whenever a loss of CAN bus
communication is detected with the ignition switch in the ON position.

Each headlamp includes an integral reflector adjustment screw (domestic markets) or screws (export markets) to
be used for static aiming of the headlamps.

HEADLAMP DELAY

The headlamp delay feature includes the left (lighting) multi-function switch, the SCM, the EMIC and the
TIPM. This feature has customer programmable delay intervals of 0 seconds (disabled), 30 seconds, 60 seconds
and 90 seconds. If the left multi-function switch remains in the headlamp ON position until after the ignition
switch is turned to the OFF position, then the headlamps will remain illuminated until after the selected delay
interval has elapsed. The park lamps will not stay ON during the headlamp delay interval. The default delay
interval is zero seconds (disabled), but can be reprogrammed by the customer using the customer programmable

2007 Dodge Nitro R/T

2007 ACCESSORIES AND EQUIPMENT Lamps/Lighting - Exterior - Service Information - Nitro