Principles of Operation
Note. The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).
The parking aid sensors detect objects approximately 152 cm (60 in) from the rear of the vehicle, 50 cm (20 in) from the rear side of the vehicle, and 30 cm (12 in) above the ground. The Parking Aid Module (PAM) calculates the distance to an object within the 170 degree semicircular area around the rear of the vehicle. A variable warning tone is generated from a parking aid speaker. The parking aid speaker increases its warning tone rate as the vehicle gets closer to an obstacle. When an object is detected within 25 cm (10 in) of the sensors, the warning tone becomes continuous.
The parking aid speaker has 2 functions for vehicles equipped with the parking aid system and Cross Traffic Alert (CTA) system. The parking aid speaker emits an audible warning tone to notify the driver of impeding traffic from the side of the vehicle when backing out of parking spaces. Refer to SIDE AND REAR VISION for cross traffic alert information.
The parking aid system is enabled when the ignition switch is in the RUN position and the REVERSE (R) gear is selected. The parking aid system is disabled if a fault is detected in 1 of the 4 sensors, the parking aid speaker, or the PAM . A fault is indicated by the message center displaying the message "CHECK PARK AID".
The PAM is on the High Speed Controller Area Network (HS-CAN) and can be diagnosed with a scan tool. The following chart describes network messages used by the PAM .
Normal Operation
The parking aid system is enabled when the ignition switch is in the RUN position and the REVERSE (R) gear is selected. The Parking Aid Module (PAM) receives a reverse gear input from the PCM through the High Speed Controller Area Network (HS-CAN). A reference voltage and signal return is supplied to the parking aid sensors from the PAM . The PAM receives an input signal from each individual parking aid sensor. The system can be disabled through the message center which is part of the Instrument Panel Cluster (IPC).
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Parking aid sensor(s) alignment
- Parking aid sensor(s)
- PAM
- Rear bumper cover
The Parking Aid Module (PAM) supplies a reference voltage and signal return to the parking aid sensors. A fault condition occurs when the PAM detects an open in the parking aid sensor circuits or the parking aid sensor input signal is open or shorted to ground.
| DTC Description | Fault Trigger Conditions |
|---|---|
| B1B44:14 - Right Rear Outer Sensor: Circuit Short To Ground Or Open | A continuous and on-demand DTC that sets when any of the right rear outer parking aid sensor circuits are open or the sensor signal line is shorted to ground. |
| B1B46:14 - Right Rear Inner Sensor: Circuit Short To Ground Or Open | A continuous and on-demand DTC that sets when any of the right rear inner parking aid sensor circuits are open or the sensor signal line is shorted to ground. |
| B1B48:14 - Left Rear Outer Sensor: Circuit Short To Ground Or Open | A continuous and on-demand DTC that sets when any of the left rear outer parking aid sensor circuits are open or the sensor signal line is shorted to ground. |
| B1B50:14 - Left Rear Inner Sensor: Circuit Short To Ground Or Open | A continuous and on-demand DTC that sets when any of the left rear inner parking aid sensor circuits are open or the sensor signal line is shorted to ground. |
DTC FAULT TRIGGER CONDITION CHART
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Parking aid sensor(s)
- PAM
The Parking Aid Module (PAM) supplies a reference voltage and signal return to the parking aid sensors. A fault condition occurs when the PAM detects a short to voltage on the parking aid sensor signal circuit.
| DTC Description | Fault Trigger Conditions |
|---|---|
| B1B44:12 - Right Rear Outer Sensor: Circuit Short To Battery | A continuous and on-demand DTC that sets when the right rear outer parking aid sensor signal line is shorted to battery voltage. |
| B1B46:12 - Right Rear Inner Sensor: Circuit Short To Battery | A continuous and on-demand DTC that sets when the right rear inner parking aid sensor signal line is shorted to battery voltage. |
| B1B48:12 - Left Rear Outer Sensor: Circuit Short To Battery | A continuous and on-demand DTC that sets when the left rear outer parking aid sensor signal line is shorted to battery voltage. |
| B1B50:12 - Left Rear Inner Sensor: Circuit Short To Battery | A continuous and on-demand DTC that sets when the left rear inner parking aid sensor signal line is shorted to battery voltage. |
DTC FAULT TRIGGER CONDITION CHART
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Parking aid sensor
- Parking aid bumper harness
- PAM
The Parking Aid Module (PAM) calculates the distance to an object by the use of 4 ultrasonic sensors mounted in the rear bumper. The parking aid sensors can detect obstructions in the path behind the vehicle.
The attenuation time for the rear parking aid sensors is the time required for a sensor to detect the distance to an object expressed in milliseconds (ms). A fault condition occurs when the signal or the attenuation time is out of normal range.
| DTC Description | Fault Trigger Conditions |
|---|---|
| B1B44:96 - Right Rear Outer Sensor: Component Internal Failure | A continuous and on-demand DTC that sets when the right rear outer parking aid sensor has internally failed or has an incorrect attenuation time. |
| B1B46:96 - Right Rear Inner Sensor: Component Internal Failure | A continuous and on-demand DTC that sets when the right rear inner parking aid sensor has internally failed or has an incorrect attenuation time. |
| B1B48:96 - Left Rear Outer Sensor: Component Internal Failure | A continuous and on-demand DTC that sets when the left rear outer parking aid sensor has internally failed or has an incorrect attenuation time. |
| B1B48:96 - Left Rear Inner Sensor: Component Internal Failure | A continuous and on-demand DTC that sets when the left rear inner parking aid sensor has internally failed or has an incorrect attenuation time. |
DTC FAULT TRIGGER CONDITION CHART
This pinpoint test is intended to diagnose the following
- Parking aid sensor
- PAM
The Parking Aid Module (PAM) supplies a reference voltage and signal return to the parking aid sensors. A fault condition occurs when the PAM detects a short to ground or signal return circuit on the parking aid sensor voltage supply circuit.
- DTC B1B58:11 (Rear Sensor Power Circuit: Circuit Short to Ground) - sets when the sensor voltage supply circuit is shorted to ground or to the signal return circuit.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Parking aid sensor(s)
- Parking aid bumper harness
- PAM
When the parking aid sensors detect obstructions in the path behind the vehicle a variable rate warning tone is generated from a parking aid speaker. The parking aid speaker increases the warning tone rate as the vehicle gets closer to an obstacle. A fault condition occurs when the Parking Aid Module (PAM) detects an open, short to ground or short to voltage on the parking aid speaker circuits.
- DTC B1B52:12 (Rear Sounder-Park Aid: Circuit Short To Battery) - sets when the sounder circuit is shorted to voltage.
- DTC B1B52:14 (Rear Sounder-Park Aid: Circuit Short To Ground Or Open) - sets when the sounder circuit is open or shorted to ground.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- PAM
- Parking aid speaker
A variable rate warning tone is generated by the parking aid sounder. A volume cutback request message is sent to the Instrument Panel Cluster (IPC) from the Parking Aid Module (PAM) over the High Speed Controller Area Network (HS-CAN), then gatewayed to the Audio Control Module (ACM) to decrease the volume of the audio system, so that the parking aid sounder can be clearly heard.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- PAM
- ACM
Note. The luggage compartment lid must be closed for correct operation of the video camera system.
The rear video camera system is used to assist the driver while reversing or parking the vehicle. For vehicles without navigation, the image of the area behind the vehicle is displayed in the LH side of the auto-dimming interior mirror assembly. For vehicles with navigation, the image of the area behind the vehicle is displayed in the Front Display Interface Module (FDIM). A dashed line on the displayed image represents the center of the vehicle and 3 color-coded lines (red, yellow, green) identify different zones between the rear of the vehicle and objects.
Note. The color-coded lines may not indicate accurate or consistent distances between objects located behind the vehicle and the rear of the vehicle. This normal condition is due to variances in vehicle ride height, including, but not limited to, vehicle loading.
For vehicles without navigation, the signal from the rear video camera is sent to the auto-dimming interior mirror display on a pair of shielded video circuits. For vehicles with navigation, the signal from the rear video camera is sent to the FDIM on a pair of shielded video circuits. The displayed video image is horizontally inverted and is viewed from the video camera perspective to mimic a conventional mirror image. The rear video camera system is active with the ignition in RUN and the transmission selector in the REVERSE (R) position.
For vehicles without navigation, with the gear selector in REVERSE (R) position, a reverse voltage signal is sent to the auto-dimming interior mirror and the video camera supplying power to the system. The video camera signal is sent to the auto-dimming interior mirror. The video signal from the video camera displays an image on the LH side of the auto-dimming interior mirror.
For vehicles with navigation, with the gear selector in the REVERSE (R) position, a reverse voltage signal is sent to the video camera supplying power to the camera. A reverse signal is also sent from the Instrument Panel Cluster (IPC) to the Audio Control Module (ACM) over the Medium Speed Controller Area Network (MS-CAN), enabling the system. The video signal from the video camera displays an image on the Front Display Interface Module (FDIM).
This pinpoint test is intended to diagnose the following
- Fuse
- Wiring, terminals or connectors
- Video camera
- Auto-dimming interior mirror (without navigation)
- FDIM (with navigation)
For vehicles without navigation, with the gear selector in REVERSE (R) position, a reverse voltage signal is sent to the auto-dimming interior mirror and rear video camera supplying power to the system. The video camera signal is sent to the auto-dimming interior mirror. The video signal from the video camera displays an image on the LH side of the auto-dimming interior mirror.
For vehicles with navigation, with the gear selector in the REVERSE (R) position, a reverse voltage signal is sent to the video camera supplying power to the camera. A reverse signal is also sent from the Instrument Panel Cluster (IPC) to the Audio Control Module (ACM) over the Medium Speed Controller Area Network (MS-CAN), enabling the system. The video signal from the video camera displays an image on the Front Display Interface Module (FDIM).
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Video camera
When the gear selector is in the REVERSE (R) position, a reverse voltage signal is sent to the auto-dimming interior mirror and rear video camera supplying power to the system. The video camera signal is sent to the auto-dimming interior mirror. The video signal from the video camera displays an image on the LH side of the auto-dimming interior mirror.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Auto-dimming interior mirror