Dodge Nitro. Manual - part 641

OPERATION 

BACKUP LAMP SWITCH 

The backup lamp switch controls a path to ground for the Totally Integrated Power Module (TIPM) on the 
reverse switch signal circuit. The TIPM reads this input through an internal pull-up, then controls an output 
through a high side driver that regulates the flow of battery voltage to the backup lamp bulbs as appropriate on 
the backup lamp feed circuit. The switch plunger is mechanically actuated by the gearshift mechanism within 
the transmission, which will depress the switch plunger and close the switch contacts whenever the REVERSE 
gear has been selected. The switch receives ground at all times through a take out and eyelet terminal of the 
engine wire harness that is secured by a nut to a ground stud on the body sheet metal within the engine 
compartment of the vehicle. 

The backup lamp switch as well as the hard wired inputs and outputs of the switch may be diagnosed using 
conventional diagnostic tools and procedures. Refer to the appropriate wiring information. 

DIAGNOSIS AND TESTING 

BACKUP LAMP SWITCH 

1. Disconnect and isolate the battery negative cable.  

2. Raise and support the vehicle.  

3. Locate and disconnect the engine wire harness connector from the backup lamp switch connector 

receptacle.  

4. Check for continuity between the two terminal pins in the backup lamp switch connector receptacle. 



With the gear selector lever in the REVERSE position, there should be continuity.  



With the gear selector lever in any position other than REVERSE, there should be no continuity.  

5. If the switch fails either of these two continuity tests, replace the ineffective backup lamp switch.  

BRAKE LAMP SWITCH 

DESCRIPTION 

BRAKE LAMP SWITCH 

 

2007 Dodge Nitro R/T 

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

  

Fig. 6: Brake Lamp Switch 
Courtesy of CHRYSLER LLC 

The brake lamp switch (2) is a three circuit, spring-loaded plunger actuated switch that is secured to the steering 
column support bracket under the instrument panel on the driver side of the vehicle. The molded plastic switch 
housing has an integral connector receptacle (1) containing six terminal pins and featuring a Connector Position 
Assurance (CPA) lock. The switch is connected to the vehicle electrical system through a dedicated take out of 
the instrument panel wire harness. 

The switch plunger (3) extends through a mounting collar (4) on one end of the switch housing. The plunger has 
a one time telescoping self-adjustment feature that is activated after the switch is installed by moving an 
adjustment release lever (5) on the opposite end of the switch housing clockwise, until it locks into a position 
that is parallel to the connector receptacle. 

An installed brake lamp switch cannot be readjusted or repaired. If the switch is damaged, ineffective, or 
removed from its mounting position for any reason, it must be replaced with a new unit. 

OPERATION 

BRAKE LAMP SWITCH 

The brake lamp switch controls three independent circuits. These circuits are described as follows:

 

2007 Dodge Nitro R/T 

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

  



Brake Lamp Switch Circuit - A normally open brake lamp switch circuit receives a battery voltage 
input, and supplies this battery voltage to the brake lamps and the Controller Antilock Brake (CAB) on a 
brake lamp switch output circuit only when the brake pedal is depressed (brake lamp switch plunger 
released).  



Brake Lamp Switch Signal Circuit - A normally closed brake lamp switch signal circuit receives a 
direct path to ground, and supplies this ground input to the Powertrain Control Module (PCM) on a brake 
lamp switch sense circuit only when the brake pedal is released (brake lamp switch plunger is depressed). 



Speed Control Circuit - A normally closed speed control circuit receives a battery voltage input from the 
PCM on a speed control supply circuit, and supplies this battery voltage to the speed control servo 
solenoids (dump, vacuum, and vent) on a speed control brake switch output circuit only when the speed 
control system is turned ON and the brake pedal is released (brake lamp switch plunger is depressed).  

The components of the self-adjusting brake switch plunger consist of a two-piece telescoping plunger, a split 
plunger locking collar, and a release wedge. The release lever has a shaft with a wedge that spreads the plunger 
locking collar to an open or released position. After the switch is installed and the brake pedal is released, the 
plunger telescopes to the correct adjustment position. When the release lever is moved to the release position, 
the wedge is disengaged from the locking collar causing the collar to apply a clamping pressure to the two 
plunger halves, fixing the plunger length. 

The brake lamp switch as well as the hard wired inputs and outputs of the switch may be diagnosed using 
conventional diagnostic tools and procedures. Refer to the appropriate wiring information. 

DIAGNOSIS AND TESTING 

BRAKE LAMP SWITCH 

WARNING:

To avoid serious or fatal injury on vehicles equipped with airbags, disable 
the Supplemental Restraint System (SRS) before attempting any steering 
wheel, steering column, airbag, Occupant Classification System (OCS), 
seat belt tensioner, impact sensor, or instrument panel component 
diagnosis or service. Disconnect and isolate the battery negative (ground) 
cable, then wait two minutes for the system capacitor to discharge before 
performing further diagnosis or service. This is the only sure way to 
disable the SRS. Failure to take the proper precautions could result in 
accidental airbag deployment.

CAUTION: Do not remove the brake lamp switch from the mounting bracket. The self-

adjusting switch plunger is a one time only feature. If the switch is 
removed from the mounting bracket, it MUST be replaced with a new 
switch.

 

2007 Dodge Nitro R/T 

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

  

Fig. 7: Brake Lamp Switch Terminal Identification 
Courtesy of CHRYSLER LLC 

1. Disconnect and isolate the battery negative cable.  

2. Disconnect the wire harness connector from the brake lamp switch.  

3. Using an ohmmeter, perform the continuity tests at the terminal pins (1) in the brake lamp switch 

connector receptacle as shown in the Brake Lamp Switch Tests table. 

BRAKE LAMP SWITCH TESTS TABLE 

4. If the switch fails any of the continuity tests, replace the ineffective brake lamp switch as required.  

REMOVAL 

BRAKE LAMP SWITCH 

BRAKE LAMP SWITCH TESTS 

PLUNGER POSITION (2) 

CONTINUITY BETWEEN (1) 

Released (Extended)

Pins 1 and 2

Compressed (Depressed)

Pins 3 and 4, 5 and 6

WARNING:

To avoid serious or fatal injury on vehicles equipped with airbags, disable 
the Supplemental Restraint System (SRS) before attempting any steering 
wheel, steering column, airbag, Occupant Classification System (OCS), 
seat belt tensioner, impact sensor, or instrument panel component 

 

2007 Dodge Nitro R/T 

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