Anti-lock light is on!

[Spector5]

Anti-lock warning lamp is on. However, no DTC's present on link.

Yes, I have failed to look to see if it would even show a DTC'S due to being obd1,
But it just starting happening recently.

I did get a malfunctioning knock sensor DTC, however I don't see the relation between the two? Yes, brake fluid is full!

Any suggestions on where to begin
The search?

 

[jtmcinder]

Start by checking brake fluid level.

 

[90tsi6bolt]

Check wheel sensor wires an connections, if they are not broken or anything check brake fluid resivor, but you still could have a open or shorted wheel sensor inside the sensor it's self