Q: ABS/Parking warning lights back on after supposed fix

For several years the ABS/Parking warning light was on. Using the ‘short out the diagnostic wire’ I got error code 9, so I replaced the speed sensor and that solved that problem. Today has been a rainy day and the ABS/Parking warning light came on again. This time, though, it will not flash the error code. I found the diagnostic wire (black and white stripe) by going to the module and then immediately grounded it to a good ground just off the RWAL harness. But nothing happened; it did not help. I also tried to go straight from the wire and all fuses are in good condition, plus the light came on when I turned the key in the ignition. I am wondering why it will not flash the error code and thinking that perhaps the problem is a failed RWAL module. Also, a month ago I got a brake inspection and they reported that all 4 brakes have 40% wear, so those should be okay for a while. I will appreciate your help in your giving me a diagnosis for my van. Thanks.