The Forward Collision/Active Safety System may be inoperative on some 2018-2019 Tahoe, Suburban, Yukon, and Escalade models. DTCs B390A 45 (Short Range Object Sensor – Variant Not Programmed), B390A 58 (Short Range Object Sensor – Performance), and/or DTC B390A 67 (Short Range Object Sensor – Incorrect Assembly) may be set. (Fig. 19)
Fig. 19
The cause of the condition may be a combination of the following:
- The B233 Radar Sensor Module – Short Range performs internal fault detection on itself, and the module continually runs the program to detect faults.
- If the B233 Radar Sensor Module – Short Range has detected an internal malfunction, it will not function and the Active Safety System will be inoperative.
The two front radar sensor modules – short range (Fig. 20) are used to measure the distance to objects that are within 98 ft. (30 m) of the front of the vehicle. The radar sensor modules – short range improve cut-in detection, which are objects that enter the vehicle path from the side and are not necessarily detected by the front-view camera and radar sensor module – long range.
Fig. 20
At the rear of the vehicle, the active safety control module uses the two radar sensor modules – short range (Fig. 21) and the parking assist control module as part of the backing warning system and the rear automatic braking system.
Fig. 21
Blocked Radar
If DTC B390A 58 is set, check for anything that can interfere with the radar signal. DTC B390A 58 sets when the control module does not see the expected change to a parameter(s) in response to a particular event.
Verify that the area in front of the radar is clean of mud, ice, snow, etc. Also verify that the fascia panels in front of the radar are not damaged or obstructed by any add-on accessories or emblems.
If the vehicle fascia is clean, unobstructed, and damage free, and DTC B390A 58 is still set as current, the radar sensor has detected a blockage condition and will not been able to clear it until certain conditions are met.
Drive the vehicle at a speed greater than 6 mph (9 km/h) and allow the radar sensor to be exposed to other vehicles/traffic in the direction of the radar sensor field of view. Usually, a short drive in normal traffic conditions will allow the radar sensor to clear the blockage condition.
Incorrect Installation
DTC B390A 67 may set if a B233 Radar Sensor Module – Short Range is reinstalled on the incorrect side of the vehicle. DTC B390A 67 sets when the control module has detected that the component has been incorrectly installed or there are polarity errors. The B233 Radar Sensor Module – Short Range cannot be swapped from side-to-side once they have been installed on a vehicle.
Programming and Set-Up
If DTC B390A 45 is set, it may be due to the radar not learning the vehicle position correctly, rather than an indication of an actual software programming issue. DTC B390A 45 will set to indicate that it may be necessary to program subsystem option content. To correct this issue, perform the programming and set-up steps using the Service Programming System (SPS).
– Thanks to Hassan Abdallah
