Quick bit of advice for any ABS related problems:
I've had numerous ABS fault indications over the last 12 years of Corrado motoring, as has been said, it's usually the one of the ABS sensors.
Cleaning them has never cured any faults for me, it's generally an internal failure of the sensor probably due to water ingress.
What is useful is a simple way of narrowing it down to which sensor it is. Just measure the resistance of all four sensors with a digital multimeter and compare the values. My most recent intermittent failure which after a while became a hard failure showed the following values;
Three sensors @ 1250 ohms
One @ 1700 ohms
The high res one was replaced, fault gone.
Hope this may help someone save time and money.
PS. does anyone know any alternative sensors for the rear, I'm sure its only the cable and connector that make them corrado specific?