00594: Front Airbag Firing Circuit

Circuit fault

What 00594 means

Most firing codes name a single igniter. This one covers the front group, which is a useful distinction when you are diagnosing. A fault that affects both front bags at once tends to live where the two circuits have something in common, which is the controller, its connector, and the section of harness they share before splitting off toward each bag.

That makes the controller connector the first place worth attention. Audi and Volkswagen controllers mount low, often under the center console area, where spilled drinks and water from a leaking sunroof drain or heater core find them. A connector that has been in water can put several firing circuits out of range at the same time.

Common causes

• Water reaching the controller connector from a sunroof drain, heater core, or windshield leak
• Corroded or spread pins across several positions in the controller connector
• A controller connector not fully seated after console or carpet work
• Harness damage where the front firing circuits run together behind the dash
• A previous repair that disturbed the main connector and left terminals backed out

Crash data or hardware fault?

00594 is a live circuit fault rather than stored crash data. The controller measures these circuits at every self test, so the code stops being current once the circuits read correctly. Crash data is written once at deployment and cannot be cleared by any scan tool, which is the situation that calls for a bench reset.

Does our reset clear it?

Clearing 00594 without repairing the circuits leaves you exactly where you started, because the controller retests within seconds of key-on. Find the common point and repair it first. If the controller also holds a deployment record from a crash, mail us the unit and we clear that record once the wiring work is finished.

Which makes throw it

This code appears on both Audi and Volkswagen with the same meaning. Because it spans both front bags, the approach is the same on either brand: start with what the two circuits share.

What to do next

Unlock and inspect the controller connector before you chase individual loops, since a fault that hits both front bags at once usually lives at the point they meet. Look for moisture staining, green terminals, and any pin that sits lower than its neighbors. Check the carpet under and around the controller for dampness while you are there, because a wet floor explains this code more often than a damaged airbag does. Related codes: 00592, 00595, B1660.