Rear Only Parking Aid Camera
System Diagram
Network Message Chart
IPMA Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Camera setting request | APIM | Commands the zoom level on and off based on driver inputs through the audio system display. |
| Gear lever position | GSM | Enables the video display when reverse (R) is selected. |
| Parking aid sensor data | IPMA | Generates the visual highlights in the zone where an object is detected by the rear parking aid system. |
| Steering wheel angle | ABS module | Generates the intended vehicle path for the active guideline feature. |
| Vehicle speed | PCM | When the video delay feature is turned on, this message is used to turn the rear camera display off after the vehicle speed exceeds a preset threshold. |
APIM Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Camera settings | IPMA | Displays the current status for active guidelines and visual park aid alert. |
| Gear lever position | GSM | Enables the video display when reverse (R) is selected. |
| Parking aid sensor data | IPMA | Generates the visual highlights in the zone where an object is detected by the rear parking aid system. |
| Rear camera on demand request | IPMA | Used by the APIM to command the audio system display on when the rear camera on demand is requested. |
| Vehicle speed | PCM | When the video delay feature is turned on, this message turns the rear camera display off after the vehicle speed exceeds a preset threshold. |
ABS Module Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Steering angle | PSCM | The ABS module uses the steering angle sensor data to generate the steering wheel angle message that is sent to the IPMA to support the active guideline feature. |
Image Display
The rear parking aid camera image is displayed by the audio system display when reverse (R) is selected. To determine the transmission gear position and enable the camera display, the GSM sends the gear position message to the IPMA.
The camera is on any time it receives voltage (when the ignition is on), but a video signal is only generated under certain conditions. When reverse (R) is selected, the camera continuously generates a video signal. When any gear except reverse (R) is selected, the camera turns the video signal off when the vehicle speed reaches 16 km/h (10 mph), and turns the video signal on when vehicle speed falls below 8 km/h (5 mph). If the camera is not configured properly, some features may be inoperative. The camera sends the video signal on coaxial cable to the APIM, which displays the image on the audio system display.
The liftgate must be fully closed for correct operation of the rear parking aid camera system.
The following parking aid camera system features are driver selectable:
- Visual park aid alert -- allows the driver to see the object causing the parking aid system to sound.
- Manual zoom -- allows the driver to manually zoom the image.
- Video delay -- allows the driver to see the image behind the vehicle after the vehicle is shifted out of reverse (R) into any gear other than park (P).
The following camera system features are not driver selectable:
- Fixed guidelines -- assists the driver with aligning the vehicle with an object.
- Active guidelines -- displays the intended path of the vehicle based upon steering wheel input.
The audio system display settings menu turns the visual park aid alert and video delay on and off. The visual park aid alert and video delay features are generated within the APIM.
Camera Communication
The IPMA and the rear parking aid camera communicate via a LVDS network over a coaxial cable. The IPMA is the master module, and it sets and stores Diagnostic Trouble Codes (DTCs) for the rear parking aid camera and the communication network.
The messages sent from the IPMA to the camera are:
- Camera configuration data
- Display manual zoom request
- Guideline on/off request
- Liftgate ajar status
- Steering angle
- Standby enable/disable request
The messages sent from the camera to the IPMA are:
- Camera status
- Display zoom status
- Camera part number data
- Guideline status
Visual Park Aid Alert
The visual park aid alert feature displays a visual highlight in the zone where an object has been detected by the rear parking aid system. This feature utilizes the parking aid sensor data from the IPMA to generate the visual highlights on the video image. When reverse (R) is selected and an object is detected by a rear parking aid sensor, the parking aid sensor data message from the IPMA is used by the APIM to generate the alert.
If the visual park aid alert feature is enabled, the feature is still operational even if the rear parking aid system has been disabled by the driver.
The on-screen alert transitions may not match changes in the audible parking aid alert tone frequency.
Fixed Guidelines
The rear parking aid camera fixed guidelines feature displays guidelines on top of the video image to assist the driver with alignment of the vehicle. A dashed line on the displayed image represents the center of the vehicle and 3 color-coded lines identify different zones between the rear of the vehicle and objects. The rear parking aid camera generates the fixed guidelines over the video image.
The guidelines are not shown when reverse (R) is not selected (video delay active).
Fixed guidelines are not shown when the liftgate is open.
The color-coded lines cannot indicate accurate or consistent distances between the rear of the vehicle and objects shown in the video image. This normal condition is due to variances in vehicle ride height including, but not limited to vehicle loading.
Active Guidelines
The active guidelines feature displays dynamic guidelines that correspond to the projected path of vehicle travel, based on the current steering angle. Several modules are involved in generating the steering angle data used to support the active guidelines. The PSCM monitors the steering angle sensor and sends the steering wheel angle sensor data to the ABS. The ABS module uses this message from the PSCM to generate the steering angle message that is sent to the IPMA. The IPMA sends the steering angle data to the rear parking aid camera. The rear parking aid camera uses this data to generate the active guidelines over the video image.
If the steering wheel is in the straight-ahead position or if the liftgate is open, the active guidelines are not shown.
The guidelines are not shown when reverse (R) is not selected (video delay active).
If the battery has been disconnected or discharged, or a module is disconnected or replaced, the active guidelines may be inoperative until the vehicle is driven on a flat and smooth road at 32 km/h (20 mph) or more, with hands placed loosely on the steering wheel and minimal steering correction for approximately 30 seconds. If the guidelines remain inoperative, it may be necessary to disconnect the battery for 5 minutes with the driver's door open, then drive the vehicle for 8 kilometers (5 miles) in normal city driving before performing the procedure described above.
Manual Zoom
The manual zoom feature is generated by the rear parking aid camera and has one level of zoom. If the manual zoom feature is on and the vehicle is shifted out of reverse (R), the manual zoom feature is disabled and must be re-enabled the next time reverse (R) is selected.
To turn the manual zoom feature on and off, the driver uses an on-screen button located on the audio system display while in reverse (R). The driver generated commands originate at the audio system display, which is hardwired to the APIM. The APIM sends the driver generated commands to the IPMA. The IPMA sends the zoom command to the rear parking aid camera. The zoom is generated by the rear parking aid camera.
Video Delay
When the video delay is turned on the APIM keeps the rear video display enabled after the transmission is shifted out of reverse (R) into any gear other than park (P), until the vehicle speed reaches 8 km/h (5 mph). With the delay off (default) the image displays until the transmission is shifted out of reverse (R).