Steering Column Switches

Steering Column Switches

Principles of Operation

Push Button Start System

The push button start system uses an electronic module in place of a conventional lock cylinder operated ignition switch. The Remote Function Actuator (RFA) module applies battery voltage to the same 3 circuits that a conventional ignition switch would use to achieve the 4 standard ignition states OFF, ACC, RUN and START. The RFA (Remote Function Actuator) module receives input from a momentary type start/stop switch mounted in the instrument panel, the Brake Pedal Position (BPP) switch and wireless input from the Intelligent Access (IA) key fob. Changing the ignition state is accomplished by pressing the start/stop switch in combination with the brake pedal. The RFA (Remote Function Actuator) module uses input from the IA (Intelligent Access) key fob to authorize use of the vehicle.

Intelligent Access (IA) Key Fob

To achieve any ignition state other than OFF, the IA (Intelligent Access) key fob must be present inside the vehicle. The driver need not perform any actions on the IA (Intelligent Access) key fob to operate the push button start system. It is sufficient that the IA (Intelligent Access) key fob is located inside the vehicle when the start/stop switch is pressed. Pressing the start/stop switch triggers radio frequency communication between the IA (Intelligent Access) key fob and the RFA (Remote Function Actuator) module. If the IA (Intelligent Access) key fob is not present when the start/stop switch is pressed, the push button starting system will not transition from the ignition OFF state and NO KEY DETECTED will be displayed in the message center.

Backup Antenna

If the battery inside the IA (Intelligent Access) key fob is weak, if the IA (Intelligent Access) key fob is damaged or if excessive ambient Radio Frequency Interference (RFI) prevents communication between the RFA (Remote Function Actuator) and the IA (Intelligent Access) key fob, the backup antenna located in the glove box provides a secondary means for the RFA (Remote Function Actuator) module to validate the IA (Intelligent Access) key fob and authorize use of the vehicle. The backup antenna uses passive radio frequency identification to exchange signals with the IA (Intelligent Access) key fob, similar to the way a typical encoded Passive Anti-Theft System (PATS) key and transceiver operate. For more information on the IA (Intelligent Access) key fob and backup antenna, refer to Antitheft and Alarm Systems.

Push Button Starting System Message Center Messages

The message center provides instruction for operating the push button start system. The message center can also display warnings that could indicate a potential issue with the push button start system. The following message center messages pertain to the push buttons start system:

- PRESS BRAKE TO START- Momentarily displayed when the start/stop switch is pressed without the brake pedal being applied.

- ACCESSORY POWER ACTIVE- Displayed when the vehicle is in ACC mode.

- SHIFT TO PARK- Displayed when the start/stop switch is pressed to shut off the engine with the transmission selector lever in any position other than park.

- RESTART NOW OR FOB IS NEEDED- Displayed when the start/stop switch is pressed to shut off the engine and the IA (Intelligent Access) key fob is not detected by the RFA (Remote Function Actuator) module.

- NO KEY DETECTED- Displayed if the IA (Intelligent Access) key fob is not detected by the RFA (Remote Function Actuator) module. If this message is observed with the IA (Intelligent Access) key fob located inside the vehicle, go to Antitheft and Alarm Systems to diagnose the IA (Intelligent Access) key fob.

- STARTING SYSTEM FAULT- Displayed if the RFA (Remote Function Actuator) module receives invalid data from the PCM during PATS (Passive Anti-Theft System) authentication. If this message is observed, go to Antitheft and Alarm Systems to diagnose the PATS (Passive Anti-Theft System) concern.

Remote Function Actuator (RFA) Module Programming

If it is necessary to replace the RFA (Remote Function Actuator) module, the replacement module must be programmed. The following scan tool functions must be carried out if an RFA (Remote Function Actuator) module is installed new:

NOTE: All of the following scan tool functions must be completed before the vehicle will start.

- Programmable Module Installation (PMI)- This process configures the new module with specific vehicle information. Refer to Programmable Module Installation (PMI) in Information Bus. Programming and Relearning

- PATS (Passive Anti-Theft System) Parameter Reset- This process initiates an exchange of information between the RFA (Remote Function Actuator) module and the PCM specific to the anti-theft/engine immobilizer feature. A PATS (Passive Anti-Theft System) parameter reset must be carried out when either the RFA (Remote Function Actuator) module or the PCM is replaced. For more information, refer to Passive Anti-Theft System (PATS) Parameter Reset-Intelligent Access (IA) in Antitheft and Alarm Systems.

- IA (Intelligent Access) Key Fob Programming- This process programs the IA (Intelligent Access) key fobs to the RFA (Remote Function Actuator). If the RFA (Remote Function Actuator) module is installed new, 2 IA (Intelligent Access) key fobs will have to be programmed before the vehicle will start. For more information, refer to Key Programming Using Diagnostic Equipment-Intelligent Access (IA) in Antitheft and Alarm Systems.

Multifunction Switch

The multifunction switch controls the various components (high beam headlamps, flash-to-pass, turn signal and windshield wiper) by grounding certain SJB (Smart Junction Box) circuits and wiper motor circuits. When the SJB (Smart Junction Box) detects the specific ground, it sends a voltage to the appropriate component to activate it. The SJB (Smart Junction Box) controls the high beam headlamps, the flash-to-pass and the turn signals. The high beam headlamp and the turn signal portion are normally open switches that close when activated. The flash-to-pass switch is a momentary contact switch that grounds the SJB (Smart Junction Box) high beam headlamp circuit. The windshield wipe and wash functions are controlled directly by the multifunction switch, wiper and washer motor.

For multifunction switch concerns, refer to one of the following systems:

- For exterior lighting, refer to Lighting and Horns.

- For wipers and washers, refer to Wiper and Washer Systems.

Steering Column Switch

For adjustable steering column switch diagnostic information, refer to Steering Column