Please can anyone help me. I’ve had y GTO 3l twin turbo for 10 years and love it! In December 2016 the abs light came on at about 4mph everytime. So far I’ve had the car in the garage about 10 times. I was told it was the speed sensors, front and rear drivers side, so replaced all hubs with sensors. ABS light still coming on so tested again and I was told it was the ABS pump. This was replaced. The light was then on all the time. The pump was replaced again, and back to square one, light on at 4mph. I was then told (auto electrical place each time) that it was the relays in the ABS pump. He cleaned them and the light didn’t come on at all… until 10 days later, and back on at 4mph. I’ve just bought in brand new relays from the USA, had them fitted, and the problem persists. Can anyone help me (please be gentle and not too technical, I’m a lass!). Where can I go where someone can tell me what the issue is and sort it? (I’m in North East England). Or can anyone guide me as to what it is and what to do next? So far it’s cost me about £1200 in parts and labour and I’m no further forward
Have you tried swapping the abs ecu maybe you could borrow one to try from someone lives close to you.
Where are you based?
Jerry 
Would ov been cheaper to deleted and bought bigger brakes!
Hi Ellen
Sent you a pm, Jerry
Hi have you checked under the front passage side plastic wheel housing if you look at the wiring towards the front their are 4x diodes taped to the main harness when I tooked at mine removed the tape one of them just fell apart from the wiring there should be 4 of which control the power to the abs sensors they look like connectors but they are diodes on the outside of the main wiring loom ■■■■■■ stumped place to put them anyway have a look they if they are corroded let me know how you get on they have a value stamped on them .
Thanks for all the help and advice, am hoping to get this looked at very soon, by a different garage