What it means
The vehicle bus reports loss of communication with the radiator anti-tamper device. Detection of unauthorised changes to the cooling system can no longer be confirmed by this node.
At a glance
- Usually lights the warning light of the system that lost communication
How it works
The radiator anti-tamper device is a networked node used to report whether changes to the cooling system can be detected. This code sets when the vehicle's control modules stop receiving expected messages from that device, so its status cannot be confirmed.
Common causes
Most likely first.
- Bus wiring open or shorted
- Module without power or ground
- Module failed
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 for communication, voltage, and cooling-system codes, then review freeze-frame data for a wider power or network event.
- Check whether the radiator anti-tamper device appears on the scan tool and whether its status data is available.
- Inspect the device connector and harness near the radiator for damage, water, corrosion, or a loose connection.
- Check the device's power and ground circuits under the manufacturer's specified conditions.
- With the vehicle powered down as specified by the manufacturer, test its network wiring for opens, shorts, or poor connections.
- If the device has sound power, ground, and network circuits but does not respond, use the manufacturer's diagnostic procedure to confirm device failure.
Common fixes
- Reconnect and secure the radiator anti-tamper device connector.
- Repair damaged or corroded wiring at the device or its network branch.
- Restore the device's missing power or ground connection.
- Replace the device if its wiring and supplies are sound but communication does not return.
Can I keep driving?
This code alone may not affect engine operation, but it means the vehicle cannot confirm the radiator anti-tamper device's status. Watch for cooling warnings or rising temperature and stop if either occurs.
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.