I have a 51-3 on my Honda 02 EX V6 model. see thread... https://honda-tech.com/search.php?searchid=18773087


tested Relays in the ABS fuse box, and checked the fuses, thus far all is well.


what do you recommend next?
sincerely,


andrew

 

Reset the code and see if it returns. Code 51 for the ABS/TCS is a faulty modulator unit. Not sure how to test it but you should before you replace it as it is $$$ ($800 new).

 

what are the steps to replace the unit? say If I got the cheap one somewhere

 

Disconnect the electrical connectors, then the brake lines then remove the modulator unit (3 nuts?). Install the modulator unit, connect the brake lines (tighten to 11 lbf.ft), connect the modulator unit connector and the pump motor connector, bleed the brake system (proper procedure starting with front wheels). Start engine and check that ABS code has disappeared. Test drive to see if ABS light stays out.

This is from an Odyssey manual but must be similar for Accord. You know you are in the Civic section right?