00237 ABS Solenoid Valve, Front Left (N59) - Electrical Fault in Circuit

The definition

00237: ABS Solenoid Valve, Front Left (N59) - Electrical Fault in Circuit.

What to check first

Cheapest and fastest checks first:

1. Read the freeze-frame data stored with the fault - engine speed, load and temperature at the moment it logged tell you whether this happens cold, hot or under load.
2. Check the connector at the part for corrosion, and that it is fully seated.
3. Clear the code and see whether it returns, and under what conditions.

What actually causes this on a VAG

Inside the ABS unit is a block of small hydraulic solenoid valves, one set per wheel, which is how the system releases and reapplies brake pressure during an emergency stop. 00237 says the electrical circuit for the front-left valve is not behaving as expected. In practice the ABS and usually the traction and stability systems will switch themselves off with their warning lights on, and ordinary braking normally continues to work as it always did - the hydraulics are still there, you have simply lost the electronic safety net. But check the red brake warning light as well. If that has come on alongside the ABS light, the electronic brake force distribution has dropped out too, which leaves the rear brakes unregulated and able to lock before the fronts in a hard stop, particularly on a wet road or with a light load in the back. That is not a fault to run for a few weeks. Either way, drive gently, leave more room, and get it read properly rather than guessing.

Most likely causes, in order

1. Low voltage or a poor earth. An undervoltage event during cranking, a failing battery or a corroded earth can set valve circuit faults with nothing wrong in the ABS unit itself. This is especially likely if several valve or pump codes appeared at the same time. Test the battery and charging system, clear the codes and re-scan before anything else.
2. The connector at the ABS unit. The multi-plug on the ABS unit sits low in the engine bay where it gets soaked and salted. Check that it is properly latched, look for corroded or pushed-back pins, and follow the loom for chafing where it is clipped along the body.
3. Internal failure of the ABS control module. The valve coils are driven from within the electronic module bolted to the hydraulic block, and this is the usual answer once wiring and supply are proven good. Cracked solder joints on the module's internal circuit board are a well-known way for these to develop.

Worth knowing: The valve named in this code is not a part you can buy on its own - it sits inside the sealed hydraulic unit and is driven by the electronics bolted to it. Before agreeing to a complete new ABS unit, ask about a specialist module repair service, which is usually a fraction of the cost. Any replacement needs coding to the car and a proper scan-tool-assisted brake bleed. An ABS warning light showing a system malfunction is a major defect and an MOT failure on any car fitted with ABS. The same applies, with the same causes and the same checks, to the sibling codes on the other three valves: 00238 front right, 00239 rear left and 00240 rear right - and if two or more of them are stored together, treat that as a strong pointer towards supply voltage or the module rather than the valves.

Common questions

What does 00237 mean?

00237 means ABS Solenoid Valve, Front Left (N59) - Electrical Fault in Circuit. The ECU sees a problem in this circuit but cannot narrow it to a specific short or open. Start at the connector and the wiring before condemning the part.

Can I drive with 00237?

This affects a system that helps you stop or stay straight. Assume ABS and stability control are reduced or switched off until it is fixed.

Related reading

• Several warning lights on at once: usually one cause, not many
• Humming or Whining Noise on a VW or Audi: How to Place It
• The 10-minute diagnostic check before you buy a used VW or Audi
• Why the same fault code has completely different causes