Blind Spot Monitoring + Rear Cross Path Service
Technology that gives the driver the ability to detect potentially dangerous objects — outside the normal path of sight — has expanded greatly over the last five to ten years. These innovations include blind spot monitoring (BSM) and rear cross path (RCP) systems, as well as park assist. These devices enhance safety while driving, allowing the driver to detect both vehicles in blind spots and objects behind the vehicle when parking or backing out.
Blind Spot Monitoring (BSM) System
The BSM system is only active when the automatic transmission gear selector is in a position other than Reverse (R) or Park (P). The BSM mode is intended to provide a visual alert to the driver when a target vehicle is located in the lane adjacent to or just behind either outside rearview mirror. This is the blind spot zone where vision of this target vehicle is blocked.
Blind Spot Monitoring (BSM) + Park Assist Systems
The system also includes the rear cross path (RCP) feature that detects cross traffic when backing out of a parking space. It is active when the gear selector is in Reverse (R).
The width of the BSM detection zone covers one traffic lane over each side of the host vehicle (approximately 13 feet). The length of this zone starts at the outside rearview mirror and extends approximately 15 feet past the rear edge of the rear fascia.
The rear detection zones are monitored on both sides of the vehicle for objects moving toward the side of the vehicle from 1 to 2 mph and up to 22 mph.
The BSM display units, located within the sideview mirrors, provide the driver with a visual warning that says an object has been detected within one of the detection zones (commonly known as the blind spots). When a vehicle enters the blind spot, the BSM triangle icon will illuminate, provided the warning criteria are met (see Figure 1). If the driver activates the turn signal and moves the vehicle into the blind spot when a vehicle is detected, an audible signal will chime and the radio volume will be muted.
Diagnosing Problems with the BSM
This article will focus specifically on the system problems on the 2014 Dodge Caravan. When a problem occurs with any of the circuits or components in the BSM system, a Diagnostic Trouble Code (DTC) will be stored in its memory circuit. In addition, a message will be displayed in the EVIC — Service Blind Spot System or Blind Spot System Temporarily Unavailable.
If receiving the Blind Spot System Temporarily Unavailable message, there are a couple of suggestions for diagnosis. If the message appears for more than five minutes, verify that the area of each end of the rear fascia (behind the rear wheel opening) is not blocked by snow, ice or road debris. Secondly, if the rear area of the vehicle has experienced any damage where the sensors are located, the sensors might not be damaged, but could be misaligned as a result of the damage. Correct either of these two conditions, if present.
The hard wire circuits between the components related to the BSM system can be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. To rule out any wiring problems between the BSM and one of the sensors, disconnect the sensor that is suspected to be bad, then connect a sensor that is known to be good. If the signal is good, the wiring is good.
All features of the BSM system, however, cannot be diagnosed using conventional methods. The most reliable, efficient and accurate diagnostic method is the use of a diagnostic scan tool.
The Service Blind Spot System message displayed when the ignition switch is ON indicates the BSM system is unavailable due to a monitored system fault. The icons in both rearview mirrors will be illuminated until the fault is corrected.
Park Assist System
A park assist system was an optional factory-installed electronic parking aid on the 2014 Dodge Caravan and other similar FCA US LLC vehicles. During parking, this system alerts the driver to obstacles located in the path immediately behind the vehicle that might be difficult to perceive. Current park assist systems include a camera.
The park assist system is active only when the ignition switch is in the On or Start position, the parking brake is released, the transmission gear selector lever is in Reverse (R) and the vehicle’s speed is less than 8 mph decelerating, or 12 mph accelerating.
Refer to Figure 2. Four ultrasonic sensors (3) in the rear bumper fascia allow the park assist system to locate and detect obstacles in the path of the vehicle. These sensors generate ultrasonic sound pulses when triggered by the park assist module 2). The module is signaled when an echo of the reflected sound from an obstacle is received. A visible warning is displayed in the vehicle information center (1) when the vehicle comes within 31 inches of the obstacle. The system will also emit a series of audible beeps and mute the radio volume.
Figure 1. Blind Spot Icon.
Diagnosing Problems with the Park Assist System
When the park assist module monitors a problem in any circuit or component in this system, a DTC will be stored in the memory circuit and the Service Park Assist System message is displayed in the EVIC.
Figure 2. Park Assist System.
When the service message is displayed, confirm the following conditions before beginning diagnostic procedures: (1) the parking brake is not applied and (2) the rear bumper is free of ice, snow, mud or other obstructions that will prevent the system from operating properly.
All features of the park assist system, however, cannot be diagnosed using conventional methods. The most reliable, efficient and accurate diagnostic method is the use of a diagnostic scan tool.
The sensors are the main components of the system. When a problem does occur with park assist, checking sensor performance is a good idea. The DTC for performance of incorrect operation of a typical sensor is B 1295-92-PTS Sensor 8.
Note: The four sensors are numbered, right to left across the rear bumper: 8, 9, 10, 11; the suffix of the DTC for each sensor, right to left, is B 1295, B 1296, B 1297 and B 1298; the DTC for the sensor on the right-hand end of the bumper is B 1295-92-PTS Sensor 8.
The troubleshooting information for each DTC provides detailed test procedures and wiring diagrams to troubleshoot each sensor.