What it means
A receiving module detected implausible data from rear radar module A. Distance/azimuth values fail plausibility checks and are rejected; blind-spot warning and rear cross-traffic alert are inhibited.
How it works
Rear radar module A detects vehicles behind or alongside the vehicle and shares distance and direction information with driver-assistance systems. This code sets when a receiving module judges module A's data implausible and rejects it, which can disable blind-spot warning or rear cross-traffic alert.
Common causes
Most likely first.
- Module internal fault or sensor input drift
- Software version mismatch after replacement
- Gateway module routing CAN messages incorrectly
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
How to diagnose it
- Scan all modules and save freeze-frame data to identify which module rejected rear radar A's data and whether related assistance faults are stored.
- Check for blind-spot or rear cross-traffic warnings and note whether the affected functions are unavailable.
- Inspect rear radar A's sensor area for dirt, ice, impact damage, bodywork changes, or an obstruction.
- Inspect radar A's connectors and accessible wiring for looseness, corrosion, or damage, especially around the affected rear corner.
- Use a scan tool to review radar A distance and direction data, then check for related CAN or gateway communication faults.
- If the radar or rear bodywork was replaced or disturbed, verify software configuration and any required alignment or calibration.
Common fixes
- Clear dirt, ice, or other obstruction from the rear radar A area.
- Repair damaged or poorly connected radar A wiring or connectors.
- Correct gateway routing or network configuration if its messages are not reaching the receiving module correctly.
- Update or configure a replacement module to the required software version.
- Restore radar A's mounting and calibration, or replace it if an internal fault is confirmed.
Can I keep driving?
The vehicle may be drivable, but blind-spot warning and rear cross-traffic alert may not detect hazards. Check mirrors and blind spots directly, and use extra care when changing lanes or reversing.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.