0156 - Restraint system supply voltage out of tolerance airbag control unit fault

What does error code 0156 mean in the airbag control unit?

In Aston Martin vehicles, the error code 0156 reports that the supply voltage of the restraint system (SRS) deviates, depending on the form either generally, between the modules or relative to the central electronics. The airbag control unit stores the fault as soon as the deviation is detected and switches on the airbag warning light.

The power supply of the restraint system is therefore affected. In the event of a crash, the airbag control unit deploys airbags and seatbelt pretensioners, so a stable supply voltage is important for the function of the entire system.

The fault therefore does not concern an individual component, but the supply with which the modules of the restraint system operate.

How do you recognise error code 0156?

Error code 0156 is recognised by an airbag warning light that stays on permanently, does not go out by itself and indicates a fault in the restraint system. The code is stored in the fault memory of the airbag control unit, cannot be permanently erased and is read out with a diagnostic tool.

The airbag warning light therefore indicates a fault that the control unit has detected itself. Clearing the code is only possible temporarily, because the fault is stored again afterwards.

What causes error code 0156?

Error code 0156 is mainly triggered by faults in the supply voltage, which can arise from connectors, cables, a connected module or the control unit itself. Which point is affected only becomes apparent when the connections and components are checked, so the cause cannot be read from the code alone.

• Connectors or contacts on the power supply are loose, oxidised or corroded by moisture
• Cables between the modules are damaged or have a contact fault
• A connected airbag module or sensor is faulty
• A weak battery or voltage spikes from jump-starting cause the voltage to deviate
• The control unit itself is faulty

Whether one of these causes applies can be clarified with the diagnostic tool and a visual check of the connections.

In which vehicles does error code 0156 occur?

The error code 0156 is known in Aston Martin vehicles, for example on the DB11, DB12, DBS, DBX, Rapide, Vanquish, Vantage and Virage models. The Cygnet, DB7, DB9 and V12 Vantage models, which also belong to the same make, are known to show it as well.

The meaning may differ for other vehicles, and the list is not complete. Please check whether your model appears in this selection before taking further steps. If in doubt, reading out the fault memory will confirm whether the code is present on your vehicle.

How is error code 0156 resolved?

Error code 0156 is resolved by first having the fault memory read out with a diagnostic tool and narrowing down the cause. If the cause lies in connectors, cables or modules, these are checked at a specialist workshop, and if it lies in the control unit, the unit is sent to Airbag24 for repair.

Working on the airbag system should be left to qualified professionals. This applies to checking the connectors and cables as well as to removing the control unit.

If the cause lies in the control unit itself, disconnect the battery first and only then remove the airbag control unit. Then create a repair order online and send the unit to Airbag24. Checking, repairing and testing usually take 3–4 working days.

The repaired control unit comes back with all vehicle data and is ready for use as soon as it is refitted — no coding or programming is required.