After an ABS light and subsequent clockspring replacement, I found my engine dramatically ran better. The slight missing, gear noise, and 2000rpm "hiccup" (2.5 problem) disappeared. I assumed it had something to do with the sensor-ground circuit feeding noise to the other sensors. Now, many months later the problem has returned.
So after pouring over the schematics and doing a little testing, I discovered that the sensor ground, pin 3 of C1, which is that flat "natural" colored connector that plugs into the clockspring, is only used if you have cruise control. Otherwise, it serves no purpose. The horn circuit goes though pin 1 but just grounds to the column. So I released the pin and taped it back. Going to see if it has any impact on the sensor ground circuit.
So after pouring over the schematics and doing a little testing, I discovered that the sensor ground, pin 3 of C1, which is that flat "natural" colored connector that plugs into the clockspring, is only used if you have cruise control. Otherwise, it serves no purpose. The horn circuit goes though pin 1 but just grounds to the column. So I released the pin and taped it back. Going to see if it has any impact on the sensor ground circuit.
