Steering Column Switches Overview
The steering column switches are located on or around the steering column. This enables the driver to control various vehicle functions and remain focused on the task of driving. Depending on vehicle options, the steering column switches consist of
- Multifunction switch - mounted on the left side of the SASM and can be serviced separately.
- Steering wheel switches - mounted on the front of the steering wheel and can be serviced separately from the steering wheel.
- Wiper and washer switch - mounted on the right side of the SASM and can be serviced separately.
The steering column switches interface with other modules and components on the vehicle through the SASM . The SASM communicates the input of the steering column switches through a LIN to the BCM and the BCM sends the request over the CAN .
Push-Button Ignition System Overview
The push-button ignition system uses the following components to achieve the 3 ignition modes (OFF, ON and START)
- Start/stop switch
- BCM
- BPP switch
- CPP switch
- Intelligent Access (IA) key
- RFA module
In ON and START, the BCM distributes this voltage to other modules and vehicle systems through the accessory relay (inhibited during START) and the ignition relay. The BCM broadcasts an ignition mode network message over the CAN
It is not necessary for the driver to perform any actions with the Intelligent Access (IA) key to operate the push button ignition system. To achieve any ignition mode other than OFF, the Intelligent Access (IA) key must be present inside the vehicle. It is sufficient for the Intelligent Access (IA) key to be located inside the vehicle when the start/stop switch is pressed.
When the start/stop switch is pressed, the BCM needs to determine that an Intelligent Access (IA) key is present in the vehicle. For information on PATS , Refer to: PASSIVE ANTI-THEFT SYSTEM (PATS) - SYSTEM OPERATION AND COMPONENT DESCRIPTION .
When it is determined that a valid Intelligent Access (IA) key is in the vehicle, the BCM and PCM take the appropriate action based on the start/stop switch and BPP switch (automatic transmission) or CPP switch (manual transmission) input.
If the Intelligent Access (IA) key battery is weak or damaged, or if excessive ambient Radio Frequency Interference (RFI) prevents communication between the Remote Functions Receiver (RFR) module and the Intelligent Access (IA) key, the backup antenna, located on the RH side of the steering column (where a conventional ignition lock cylinder would be located), provides a secondary means for the RFA module to validate the Intelligent Access (IA) key and authorize use of the vehicle. The Remote Functions Receiver (RFR) module uses passive Radio Frequency (RF) identification to exchange signals with the Intelligent Access (IA) key.
The message center provides instructions for operating the push-button ignition system. The message center also displays warnings that indicate a potential concern with the system. These messages pertain to the push-button ignition system
- Press brake to start (automatic transmission) - Momentarily displays when the start/stop switch is pressed without the brake pedal being applied.
- No key detected - Displays if the Intelligent Access (IA) key is not detected by the RFA module while attempting to start the vehicle, or enter ON mode. If this message is observed with the Intelligent Access (IA) key located inside the vehicle, Refer to: «PERIMETER ANTI-THEFT ALARM - SYSTEM OPERATION AND COMPONENT DESCRIPTION»(ref-566978-S02501914242013071700000) .
Scheme 17
Normal Operation and Fault Conditions
The ignition switch receives fused battery voltage from BCM fuse 78 (5A). In the ACC or ON position, this voltage is sent to the BCM . In the START position, this voltage is sent to both the BCM and the PCM .
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| U300A:13 | Ignition Switch: Circuit Open | The BCM monitors the ignition switch position. This on-demand DTC sets if the BCM detects no voltage on the voltage inputs from the ignition switch. This DTC also sets when the BCM self-test is performed with the ignition switch in the OFF position. |
DTC FAULT TRIGGER CONDITIONS
When in ACC mode, the ignition switch sends voltage to the BCM . The BCM then sends out an ignition status message on the Medium Speed Controller Area Network (MS-CAN).
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| B102F:2F | Auxiliary Switch: Signal Erratic | The BCM monitors the circuit ACC input from the ignition switch during a self-test. This DTC sets if the BCM detects invalid input from the ignition switch. |
DTC FAULT TRIGGER CONDITIONS
When the ignition switch is turned to the ON position, a voltage signal is sent to the BCM . The BCM then activates the ignition relay and accessory relay, which distribute fused voltage to various components. The BCM uses a Field-Effect Transistor (FET) to control the relays. The ignition relay receives voltage from BJB fuse 23 (5A).
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| B10E7:12 | Ignition On Relay: Circuit Short to Battery | The BCM continuously monitors the control side of the ignition relay. This DTC sets if the BCM detects a short to voltage on the control circuit. When this DTC sets, the control side of the ignition relay is disabled via the Field-Effect Transistor (FET). Once the condition that caused the DTC to set is repaired, the BCM must pass a self-test in order for the DTC to clear and the system to resume normal operation. |
| B10E7:14 | Ignition On Relay: Circuit Short to Ground or Open | The BCM continuously monitors the control side of the ignition relay. This DTC sets if the BCM detects an open or a short to ground on the control circuit. When this DTC sets, the control side of the ignition relay is disabled via the Field-Effect Transistor (FET). Once the condition that caused the DTC to set is repaired, the BCM must pass a self-test in order for the DTC to clear and the system to resume normal operation. |
| B112A:12 | Ignition On Relay B: Circuit Short to Battery | The BCM continuously monitors the control side of the accessory relay. This DTC sets if the BCM detects an open or a short to ground on the control circuit. When this DTC sets, the control side of the accessory relay is disabled via the Field-Effect Transistor (FET). Once the condition that caused the DTC to set is repaired, the BCM must pass a self-test in order for the DTC to clear and the system to resume normal operation. |
DTC FAULT TRIGGER CONDITIONS
When the ignition switch is turned to the START position, a voltage signal is sent to the BCM and the PCM . The BCM then sends out an ignition status message on the Medium Speed Controller Area Network (MS-CAN) to indicate a start event and the PCM checks various inputs and bus messages in an effort to start the vehicle.
To place the vehicle in ON mode, locate the Intelligent Access (IA) key inside the vehicle and press the start/stop switch once, for at least one second, without applying the brake pedal. When in ON mode, the BCM then activates the ignition relay and accessory relay, which distributes fused voltage to various components. The BCM uses a Field-Effect Transistor (FET) to control the relays. The ignition relay receives voltage from BJB fuse 23 (5A).
To start the engine, locate the Intelligent Access (IA) key inside the vehicle and press the start/stop switch while the brake pedal is applied.
The start/stop switch provides a voltage input to the BCM , the RFA module and the PCM . The 3 modules exchange information over the High Speed Controller Area Network (HS-CAN) to determine if starting the engine is authorized. If the PATS authorizes the starting of the engine, the PCM supplies power and ground to the starter relay.
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| B10E7:12 | Ignition On Relay: Circuit Short to Battery | The BCM continuously monitors the control side of the ignition relay. This DTC sets if the BCM detects a short to voltage on the control circuit. When this DTC sets, the control side of the ignition relay is disabled via the Field-Effect Transistor (FET). Once the condition that caused the DTC to set is repaired, the BCM must pass a self-test in order for the DTC to clear and the system to resume normal operation. |
| B10E7:14 | Ignition On Relay: Circuit Short to Ground or Open | The BCM continuously monitors the control side of the ignition relay. This DTC sets if the BCM detects an open or a short to ground on the control circuit. When this DTC sets, the control side of the ignition relay is disabled via the Field-Effect Transistor (FET). Once the condition that caused the DTC to set is repaired, the BCM must pass a self-test in order for the DTC to clear and the system to resume normal operation. |
| B112A:12 | Ignition On Relay B: Circuit Short to Battery | The BCM continuously monitors the control side of the accessory relay. This DTC sets if the BCM detects an open or a short to ground on the control circuit. When this DTC sets, the control side of the accessory relay is disabled via the Field-Effect Transistor (FET). Once the condition that caused the DTC to set is repaired, the BCM must pass a self-test in order for the DTC to clear and the system to resume normal operation. |
| B108A:24 | Start Button: Signal Stuck High | The BCM continuously monitors circuit SW1 and SW2 inputs from the ignition switch. This DTC sets if the BCM detects a button press on circuit SW2 and SW1 for more than 120 seconds. |
| B108B:23 | Start Button Circuit "A": Signal Stuck Low | The BCM continuously monitors circuit SW1 and SW2 inputs from the ignition switch. This DTC sets if the BCM detects a button press on circuit SW2 and no button press on circuit SW1. |
| B108B:24 | Start Button Circuit "A": Signal Stuck High | The BCM continuously monitors circuit SW1 and SW2 inputs from the ignition switch. This DTC sets if the BCM detects a button press on circuit SW2 and SW1 for more than 60 seconds. |
| B108B:2F | Start Button Circuit "A": Signal Erratic | The BCM monitors the circuit SW1 input from the start/stop switch during a self-test. This DTC sets if the BCM detects a button press or short to voltage on circuit SW1 during a self-test. |
| B108C:23 | Start Button Circuit "B": Signal Stuck Low | The BCM continuously monitors circuit SW1 and SW2 inputs from the ignition switch. This DTC sets if the BCM detects no button press on circuit SW2 and a button press on circuit SW1. |
| B108C:24 | Start Button Circuit "B": Signal Stuck High | The BCM continuously monitors circuit SW1 and SW2 inputs from the ignition switch. This DTC sets if the BCM detects a button press on circuit SW1 and SW2 for more than 60 seconds. |
| B108C:2F | Start Button Circuit "B": Signal Erratic | The BCM monitors the circuit SW2 input from the start/stop switch during a self-test. This DTC sets if the BCM detects a button press or short to voltage on circuit SW2 during a self-test. |
DTC FAULT TRIGGER CONDITIONS
The key removal inhibit solenoid (part of the ignition switch) receives battery voltage from BCM fuse 78 (5A). When the selector lever is moved into the PARK position, the park range switch (part of the selector lever) opens, interrupting a ground circuit to the key removal inhibit solenoid. The key removal inhibit solenoid deactivates and allows the ignition lock cylinder to be turned to the OFF position and the key to be removed.
The key removal inhibit solenoid (part of the ignition switch) receives battery voltage from BCM fuse 78 (5A). When the selector lever is moved out of the PARK position, the park range switch (part of the selector lever) closes, providing a ground circuit to the key removal inhibit solenoid. The key removal inhibit solenoid activates and prevents the ignition lock cylinder from being turned to the OFF position and the key from being removed.
See also:
• CLOCKSPRING