B2350 on 2016-2019 Subaru Crosstrek: Rear Radar Communication Error Causes and Fixes

What's Unique About the 2016-2019 Subaru CROSSTREK

For the 2016-2019 Crosstrek, this code has a very specific and unusual diagnostic quirk documented by Subaru. A Technical Service Bulletin (TSB 07-174-20) confirms that when a sensor fails, the B2350 code is often logged for the sensor on the opposite side of the car. This frequently leads to misdiagnosis, where a technician might replace the wrong sensor if they are not aware of this specific bulletin. Additionally, the SRVD system on this platform can be sensitive to low voltage during engine start-up, a known issue on many Subarus from this period, making a weak battery a potential primary cause.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Generation note: This range covers the first generation (2016-2017) and the second generation (2018-2019) of the Subaru Crosstrek. The primary TSB regarding the diagnostic quirk (07-174-20) applies to the entire 2016-2019 range, indicating the issue is common to both generations. This issue is also shared across many other Subaru models from the same period.

Symptoms You May Notice

• "SRVD Disabled" message on the instrument panel or multi-function display.
• Illuminated warning light for the Blind Spot Detection (BSD) / Rear Cross Traffic Alert (RCTA) system.
• Blind spot indicator lights in the side mirrors do not illuminate when vehicles are present.
• No audible or visual alert from the Rear Cross Traffic Alert system when reversing and traffic is approaching.
• The error may appear intermittently, especially during cold weather or after the vehicle has been sitting, which often points to a battery issue.

Most Likely Causes

1. Faulty Rear Radar Sensor (on the opposite side of the code) 🔴 High Probability → Shop Collision Avoidance Sensor Subaru issued TSB 07-174-20 specifically to inform technicians that the B2350 code points to the sensor opposite the one that has actually failed. The sensors are also located in the bumper corners, making them vulnerable to minor impacts, moisture intrusion, and corrosion, which can lead to internal failure.
   How to confirm: After reading the DTC (e.g., for the left side), inspect and test the sensor on the OPPOSITE (e.g., right) side. A professional diagnostic approach may involve swapping the sensors to see if the code follows the sensor. A Reddit user confirmed that after getting a B2350 for the driver's side, they discovered damage from a parking lot hit-and-run on the passenger side rear bumper, and replacing the passenger sensor fixed the issue.
   Typical fix: Replace the faulty radar sensor assembly on the side opposite to the one indicated by the diagnostic trouble code. 🎬 See this walkthrough on how to fix the SRVD system Many owners have successfully performed this replacement without needing a dealer recalibration, though it is officially recommended.
   Est. part cost: $250-$450
2. Weak or Failing Battery 🟡 Medium Probability → Shop Vehicle Battery The SRVD control modules are sensitive to voltage drops that can occur during engine cranking with an aging or undersized OEM battery. TSB 07-90-15 was issued for earlier models due to this exact issue. Subarus of this era are known for having batteries that are sometimes barely adequate for the vehicle's electrical demands.
   How to confirm: Perform a load test on the battery. A battery that reads 12.4V at rest but drops below 10.5V during cranking is a likely culprit. Symptoms like dimming lights or a slow engine crank also point to a weak battery.
   Typical fix: Replace the vehicle's 12V battery, preferably with a high-quality AGM (Absorbent Glass Mat) type for better stability and cranking power.
   Est. part cost: $150-$350
3. Damaged Wiring or Connector ⚪ Low Probability The sensor wiring is located behind the rear bumper cover and can be damaged in a minor rear-end collision or suffer from corrosion due to road salt and moisture. Some owners have reported success simply by unplugging, cleaning with electrical contact cleaner, and securely replugging the sensor connectors.
   How to confirm: Visually inspect the wiring harness and connectors leading to both rear radar sensors for cuts, corrosion, pinched wires, or physical damage. Check for a secure connection.
   Typical fix: Repair the damaged section of the wiring harness or replace the connector pigtail. Clean corroded terminals with electrical contact cleaner.
   Est. part cost: $20-$100

Rare But Worth Checking

• Bent or Damaged Sensor Mounting Bracket:

Diagnosis Steps

1. Connect a professional scan tool capable of reading Body/Chassis codes. Note which side the B2350 code is reported for (e.g., Left or Right).
2. Perform a comprehensive battery and charging system test. Ensure the battery maintains voltage above 10.5V during engine cranking. If the battery is weak or older than 4-5 years, replace it before proceeding, as this is a very common cause.
3. If the battery is healthy, turn your attention to the radar sensor on the OPPOSITE side of the vehicle from what the code reported. For example, if the code is for the left sensor, inspect the right sensor first.
4. Remove the rear bumper cover to access the sensors. 🎬 Watch: How to remove the rear bumper cover It is wise to have replacement bumper clips on hand, as they often break during removal.
5. Visually inspect the suspected sensor, its mounting bracket, and its electrical connector for any signs of physical damage, corrosion, or loose connections. A bent bracket is a known cause.
6. If no visual damage is found, the most common repair is to replace the suspected sensor (the one opposite the code). Many owners report success without further calibration.
7. After replacement, clear the DTCs and perform a road test to verify the SRVD warning light does not return and the system functions correctly. A drive cycle of 5-10 minutes above 20 mph may be needed for the system to re-initialize.
8. If the issue persists, a professional diagnosis of the CAN bus wiring is required, or a sensor alignment procedure may be necessary using a Subaru-specific scan tool and radar reflector kit.

Parts You'll Likely Need

• Radar Assembly, Back and Side (OEM #87611AN00C) — This is the sensor unit that fails, causing the communication error. TSB 07-174-20 points to this part being the cause, but on the opposite side of the code report. The same part number is used for both left and right sides. This part number supersedes previous versions 87611AN00A and 87611AN00B.
  Trusted brands: Subaru (Genuine)
  OEM price range: $250-$450
  Aftermarket price range: Not commonly available
• AGM Vehicle Battery — A weak battery causing low voltage during engine start is a primary trigger for B2350. Upgrading to a quality Absorbent Glass Mat (AGM) battery is a common and effective preventative fix.
  Trusted brands: Interstate, DieHard, Optima, Duralast
  OEM price range: $200-$400
  Aftermarket price range: $150-$350

Related Codes That Often Appear With This One

• B2328 — This code for 'Rear Radar Internal Failure (Radar Misalignment)' can sometimes be stored as a 'Cancel Code' that is not visible with all scan tools. It points to an internal fault or physical misalignment of the sensor itself and may require a more advanced scanner to read.

Technical Service Bulletins (TSBs) & Recalls

• 07-174-20: States that for DTC B2350, the diagnostic procedure is corrected to note the fault is on the opposite side of the sensor displaying the code.

Platform-Specific Known Issues

• A critical diagnostic issue, confirmed by TSB 07-174-20, causes the B2350 code to be stored for the opposite side of the actually failed sensor.
• The SRVD system is highly sensitive to voltage drops during engine cranking, making a weak battery a more common cause for this code than on many other vehicles.

Mechanic-Grade Diagnostic Values

• CAN Bus Resistance — expected: ~60 Ohms. Failure: A reading of ~120 Ohms indicates an open in the circuit or one of the terminating resistors is disconnected. A reading near 0 Ohms indicates a short between the CAN High and CAN Low wires.
• CAN High (CAN-H) Voltage to Ground — expected: ~2.6V - 2.7V (average, with system active). Failure: Significant deviation, such as 0V (short to ground) or 5V/12V (short to power), indicates a wiring fault.
• CAN Low (CAN-L) Voltage to Ground — expected: ~2.3V - 2.4V (average, with system active). Failure: Significant deviation indicates a wiring fault on the CAN Low line.
• Radar Sensor LH Power Supply Voltage — expected: 10 V or more. Failure: Voltage below 10V points to an open or short circuit in the power supply harness to the sensor.

Hidden / Shadow Codes Worth Checking

• B2328: Rear Radar Internal Failure (Radar Misalignment). This code is often stored as a 'Cancel Code' and is not visible on basic OBD-II scanners. It points directly to an internal sensor fault or physical misalignment. (see via A dealer-level tool like the Subaru Select Monitor (SSM) or a high-end aftermarket scanner (e.g., Autel, VXDIAG) with a 'Cancel Code(s) Display' or equivalent function is required.)

Scan Tool Commands That Help

• Subaru Select Monitor (SSM) or equivalent: Cancel Code(s) Display — Use this function when B2350 is present or the SRVD system is inoperative without other codes. It is essential for checking for hidden codes like B2328 that confirm an internal sensor failure.
• Subaru Select Monitor (SSM) or equivalent: Radar Alignment / Calibration — This function, found under 'Work Support', is officially required after replacing a radar sensor or if DTC B2328 (Radar Misalignment) is found. It initiates a calibration routine using special reflectors to ensure the sensor is aimed correctly.
• Subaru Select Monitor (SSM) or equivalent: Clear Memory — After repairs are completed, this function must be used to clear the B2350 and any related codes from both the left and right SRVD modules individually.

Wiring & Ground Locations

• Radar Sensor LH Connector (R56) — Behind the rear bumper cover on the driver's side.. This is the main connection point for the master radar sensor. A voltage check for power should be performed here. Per the service manual, measuring between pin No. 5 (+) and chassis ground should yield 10V or more with the ignition ON.
• Ground Point GB-10 — Located in the left rear quarter panel area.. This is a primary ground point for several rear body components. While not directly cited for the SRVD system in the search results, poor grounding in this area can cause intermittent communication issues for various modules.

OEM Part Supersession History

• 87611AN00A, 87611AN00B → 87611AN00C — Updated part to improve reliability and address communication errors. TSB 07-90-15 for 2015 models specifically recommended replacing original sensors with the 'B' revision to fix issues related to voltage drops.
  Heads up: The newer part numbers are direct replacements for the older ones and are fully compatible. The same part is used for both left and right sides.