VW Crafter Alarm System Failure: Dead Control Unit Alert

Having experienced something similar with my 2021 VW Transporter, I can share some relevant insights about car alarm troubles. The symptoms you describe match exactly what happened with my van, a complete power failure in the anti-theft system. After diagnostic testing, it turned out the alarm system was incorrectly coded to activate optical locking signals through the indicators. The fix was straightforward and cost 45€ for reprogramming the alarm control unit. The workshop needed about an hour to complete the work. No parts needed replacement, just a software update and recoding of the system. Before jumping to conclusions though, would you mind sharing: Are there any other electrical issues? Does the central locking still work normally? When did the false alarm problem first appear? Have you recently had any battery issues or electrical work done? This information would help determine if your Crafter has the same underlying issue. While both vehicles share similar security systems, knowing these details would confirm if we are dealing with the same problem. Remember that letting security system problems go unchecked can lead to more serious anti-theft protection failures down the line.

Last service was 2 weeks ago at 58241KM. Tests show its likely related to the immobilizer system not communicating properly with the alarm control unit. The car starts fine but the anti-theft system remains unresponsive. Our scan tool shows error code B1312. Getting similar false alarm reports from the onboard computer. The security system initially worked perfectly until these issues started appearing after the recent service. Central locking still functions normally, suggesting its isolated to the alarm module. No other electrical problems noted. Battery voltage reads normal at 12.6V. My regular workshop quoted 380€ for a complete alarm control unit replacement, which seems steep for a nearly new vehicle still under warranty. Hoping for input on whether this is a reasonable repair cost.

Thanks for those additional details about your Crafter. The symptoms definitely parallel what I experienced, though your situation sounds more complex than my initial immobilizer coding issue. The B1312 error code typically indicates a communication fault between the immobilizer and alarm control unit, which explains why your basic functions work but the alarm system remains inactive. Since these issues emerged right after servicing, there might be a connection, sometimes disconnecting the battery during maintenance can trigger security system glitches. The 380€ quote for a complete alarm control unit replacement seems unnecessarily high, especially for a 2023 model under warranty. My repair ended up being much simpler when I faced similar issues. Before agreeing to the replacement, consider these points: The car alarm system might just need recalibration due to the recent service work, A simple reset of the immobilizer system could restore proper communication, The warranty should cover security system malfunctions on such a new vehicle Would strongly suggest getting a second opinion and specifically asking about warranty coverage. My initial quote was also for a full replacement, but the actual fix required only reprogramming the alarm control module. The battery voltage looks good at 12.6V, so we can likely rule out power supply problems causing the alarm system failure.

Thanks for the detailed feedback. You make some good points about the warranty coverage, I just called the dealership and they confirmed this type of alarm system failure should be covered. Going to take it there tomorrow instead of the independent shop. Getting the second opinion was definitely worth it. The dealership thinks it might just need a reset and recoding of the alarm sensor, similar to your case. Even if they do need to replace the alarm control unit, at least it wont cost me 380€ under warranty. Good to know the battery voltage reading suggests no power failure issues. Will update once I know what exactly caused the immobilizer and security alarm problems. Really hoping its just a simple programming fix like you experienced rather than needing new parts.