trevtherev

I am hoping to sort out an intermittent fault that’s been plaguing me since I returned my tf to the road in the spring. What’s so infuriating is that it doesn’t seem to follow any rhyme or reason. As I drive along you get a sudden drop in power and the dash light all come on and off and what I can only describe as similar to limp mode. When you get to the side of the road and allow it to cut out, sometimes turning the key gives no life at all, but the second turn fires up and carries on as if nothing is wrong. I know they do not have limp mode such a mode, but it mimics the same characteristics. I have had the crank and cam sensor changed but still it hasn’t cured it
I have linked Pscan and managed to bring up 3 codes (I do not have a/c or ASB fitted)
P0500 – Vehicle speed sensor malfunction
P1539 - Power to A/f clutch circuit over current
P0562 – System voltage low
Having had a chat with someone much better at car electrics than me, he suggested checking all the earth points.
He suggested that maybe an earth is playing up, bearing in mind I’ve had both subframes out and the problem only began since putting it all back together.
To date, I’ve cleaned the earth point from battery to wing, and the Earth point on the rear of the boot under 80A fuse. I appreciate there are several more to locate and clean, and this forum has a great listing of said earth points.
He also suggested attaching an additional earth from the engine to body work and see, in the short term, if that cures the problem.

Do you think this is a realistic avenue to follow?