Parking Lamp: Description and Operation

NOTE: The Front Electronic Module (FEM), the Rear Electronic Module (REM), and the Instrument Cluster Module (ICM) must be reconfigured before installing a new module. Refer to Module Communications Network (Information Bus).

The vehicle electronic functions are divided into zones. The FEM controls the front portion of the vehicle and the REM controls the rear portion of the vehicle. These systems rely heavily on the Standard Corporate Protocol (SCP) communication network in order to transmit and receive signals. As a technician it is very important to understand:
^ where the input (command) originates from.
^ all information (messages) necessary in order for a feature to operate.
^ which module(s) receive(s) the input or command message.
^ does the module which received the input (message), control the output of the feature, or does it output a message over the SCP communication network to another module.
^ which module controls the output of the feature.

Exterior Lighting
The exterior lighting outputs are zone controlled by the FEM and REM. The front exterior lights are controlled by the FEM and the rear exterior lights are controlled by the REM. An additional function of the lighting system is a lamp outage function which indicates to the driver if certain exterior bulbs are not functioning. With a bulb inoperative, the FEM or REM will send a message to the instrument cluster and message center (if equipped with the message center), which will indicate to the driver that the lamp is inoperative with a lamp out indicator (with the message center a message will be displayed). To provide complete input and output functionality, each exterior lamp feature will be described individually. All exterior lighting is powered by the SSP feature (refer to [SSP]). A failure of all or any of the SSP features will cause inoperative exterior lighting. When diagnosing exterior lighting, it is essential to determine if all related symptoms and DTCs are controlled by the SSP feature.

Parking, Rear or License Lamps
For the LH and RH rear park, license, and LH and RH front park lamps, outputs are controlled by the REM and FEM. The headlamp switch is hardwired to the ICM. When the switch is in the headlamp or park position, the ICM will send a command via the network link to the FEM and REM. The REM and FEM will process this information and output the appropriate command to the rear park, license, and front park lamps, which are hardwired to the REM and FEM. Only the left and right rear lamps will provide lamp outage indication. Fault management of the park lamps will provide rear park lamp functionality in the event of certain multifunction switch, headlamp switch, ignition switch, REM or FEM failures. The park lamps are also part of the daytime running lamps feature.

The vehicle's electronic functions are divided into zones. The FEM controls the front portion of the vehicle and the REM controls the rear portion of the vehicle. These systems rely heavily on the SCP communication network in order to transmit and receive signals. As a technician it is very important to understand:
^ where the input (command) originates from.
^ all information (messages) necessary in order for a feature to operate.
^ which module(s) receive(s) the input or command message.
^ does the module which received the input (message), control the output of the feature, or does it output a message over the SCP communication network to another module.
^ which module controls the output of the feature.

Switched System Power (SSP)
The SSP is invoked by both the FEM and REM. This function removes power from relays that provide power to the exterior lamps, interior lamps, and power door locks. This is only accomplished when both the FEM and the REM are in sleep mode. The sleep function of the FEM and REM places the modules in sleep mode when the ignition switch is in the OFF position, and no wake up (input) signals occur for 30 minutes. The module will not sleep if the parking lamps or the hazard lamps are active. The following relays are controlled by the SSP function: SSP1, SSP2, SSP3, and SSP4. When either the FEM or REM are not in sleep mode, all SSP relays will be energized. When energized, each relay will supply power to multiple features/functions. For additional information, go to the SSP Index Component Tests and General Diagnostics
for diagnosis and testing of SSP related issues. Refer to Headlamps. Headlamp