My K-reg 800 has a problem with the ABS. I thought it suspicious when the light didn't come on at all on the dashboard - when I had a look it had been removed! I replaced the bulb and sure enough, it lit and stayed lit to indicate a fault.
No problem methinks, so I get my multimeter out and test each of the wheel sensors for continuity and voltage when the wheel is turning. No problems there so then I take the cover off the ABS unit itself and there are two relays missing! A quick visit to the scrapyard gets me two of the correct relays and now the light comes on for a few seconds then goes off as you'd expect.
Great - well, not quite. Sometimes when driving along the light will come back on again. Also when I 'test' the ABS it seems to work fine for the first second or two and then the pedal becomes hard and even with more pressure the car doesn't slow down. If I keep my foot on the pedal it eventually skids to a stop with one of the wheels locked. If I take my foot off the pedal but then brake gently the pedal is still "pulsing" as though the ABS is being triggered. After either of the above the ABS light comes on.
Any ideas? I'm guessing that one of the wheel sensors is sending an erratic signal which is confusing the ECU, but could it be the ECU or motor/valve block itself?
Darren