B1888 - Passenger airbag firing circuit, short to ground airbag control unit fault

What does error code B1888 mean in the airbag control unit?

On Alfa Romeo vehicles, error code B1888 indicates a short to earth in the ignition circuit of the passenger airbag, that is, in the circuit through which this airbag is triggered. The airbag control unit then creates an entry in the fault memory, and the airbag warning light comes on so that the fault in the restraint system is noticed.

The ignition circuit is the electrical circuit that triggers the airbag. In the event of a short to earth, a cable in this circuit unintentionally touches the vehicle's earth, which can disrupt ignition.

In the dashboard, the airbag warning light shows the status for as long as the entry remains in the fault memory.

How do you recognise error code B1888?

You recognise the fault by an airbag warning light that stays on permanently and by a stored entry in the fault memory of the airbag control unit. The entry cannot be permanently cleared, and only a readout with a diagnostic tool reveals the exact code stored in the memory.

The lamp being on does not yet prove the code. Only the readout shows whether the entry is actually present in the fault memory.

An early readout brings clarity about the actual findings.

What causes error code B1888?

A short to earth in the passenger airbag's ignition circuit can be caused by damaged wiring, a defective connector, the airbag module or the airbag control unit itself. Which of these parts is actually affected remains open for the code, because the fault can lie at any point in the ignition circuit.

• A wire in the ignition circuit whose insulation has chafed through
• Corrosion on the contacts of a connector in the ignition circuit
• A fault in the passenger airbag module that closes the circuit to earth
• A fault in the airbag control unit itself that affects the ignition circuit

The check is carried out by measuring the components of the ignition circuit one after another until the fault is found. Until then, none of the parts listed can be determined as the cause.

In which vehicles does error code B1888 occur?

This fault code B1888 is known on Alfa Romeo, specifically for the Junior 966 model. On a vehicle of this series, the code is stored in the fault memory as soon as the fault is present, and other brands or models are not named in this list.

For series that are not listed here, the meaning may differ. The list is not complete; whether a particular vehicle is affected is shown by a readout with a diagnostic tool.

How is error code B1888 resolved?

To resolve B1888, the fault memory of the vehicle is first read out with a diagnostic tool, then the connector, wiring and airbag module of the passenger airbag are specifically checked at a specialist workshop. Only once the control unit itself has been clearly identified as the cause does the repair at Airbag24 follow.

If the control unit is clearly determined to be the cause, first disconnect the battery and then remove the 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. Work on the airbag system should be left to qualified professionals.