B1476 - Supply voltage drops below permitted level airbag control unit fault

What does error code B1476 mean in the airbag control unit?

Error code B1476 reports that the ignition supply voltage drops impermissibly, i.e. that the voltage falls below the permitted range. The power supply of the airbag control unit via the ignition is affected, and the unit stores the fault and switches on the airbag warning light.

The restraint system (SRS) includes airbags and seatbelt pretensioners. In an emergency, the airbag control unit triggers them.

The code does not concern a single component, but the power supply that the airbag control unit needs for its work.

How do you recognise error code B1476?

You recognise error code B1476 by the airbag warning light being permanently lit and by an entry in the fault memory of the airbag control unit. The code cannot be permanently deleted, and it is read out with a diagnostic tool, which displays the faults stored for the vehicle.

If the entry is deleted, the code reappears at the next readout for as long as the cause is not resolved.

Deleting it alone therefore does not fix the fault, and the airbag warning light stays permanently on for as long as the code is stored.

What causes error code B1476?

Possible causes of error code B1476 are the plugs and wiring of the power supply, a weak battery, or the airbag control unit itself, if it is faulty. The code alone does not show whether the wiring, the battery or the control unit is affected.

• The plug or wiring of the power supply is loose or damaged.
• A weak battery supplies too little voltage.
• Moisture or corrosion on the contacts.
• The airbag control unit has an internal fault, for example due to aged electronic components or solder joints.

The cause lies either outside the control unit, in the power supply, or in the unit itself.

In which vehicles does error code B1476 occur?

Error code B1476 is known in Mitsubishi vehicles, for example on the models ASX, Colt, Eclipse Cross, Galant, Outlander and Pajero Sport. The list is not complete, and the meaning may differ in other vehicles, so have the code checked on the vehicle concerned in each specific case.

Whether the code is present on a particular vehicle is shown only by a readout with a diagnostic tool.

How is error code B1476 resolved?

Error code B1476 is resolved by first having the fault memory read out with a diagnostic tool and then narrowing down the cause. If the cause lies in the plug or wiring of the power supply, have these parts checked first at a specialist workshop; if it lies in the control unit, the unit is sent in.

Work on the airbag system should be left to qualified specialists. If the cause lies in the control unit itself, for example due to an internal fault, first disconnect the battery and then remove the control unit.

Then create a repair order online and send the unit to the workshop in Berlin. 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.