U0168: Lost communication with vehicle security control module

What the code tells you on its own

• System. Network. Communication faults, a module that stopped answering on the CAN bus, or sent implausible data. Often a symptom of a power or wiring problem rather than a failed module.
• Functional group. Bus communication

What we see when U0168 turns up

Measured across the diagnostics run through Wrenchlane by independent workshops, not taken from a reference table. Sightings span June 2026 to August 2026.

• 2 diagnostics carried this code.
• 1 separate workshops met it, so this is not one shop seeing the same fault repeatedly.
• 0% of the time it arrived with no symptom description at all, meaning the technician had nothing but the code to work from.
• Most often on BMW, which is where we have seen it most rather than a claim about the fleet at large.

What this page does not tell you

A code names a symptom the car noticed, not the part that failed. U0168 on one vehicle and the same code on another can have different causes, and the counts above describe what independent workshops brought to us rather than how common the fault is across all cars. Getting from the code to the cause needs the vehicle: its make, model, engine and what it is actually doing.

Run U0168 against the car in front of you. Enter the code and the symptoms and get ranked probable causes for that specific vehicle, with the checks in the order worth doing them. Free account, no card.

Other bus communication codes

• U0416, Invalid data received from vehicle dynamics control module
• U0401, Invalid data received from ECM/PCM A
• U0121, Lost communication with ABS control module
• U0100, Lost communication with ECM/PCM A
• U0167, Lost communication with immobiliser control module
• U0155, Lost communication with instrument panel cluster