4x4 Light - Driving me nuts - 06 4.8iS

[Astrok]

Both my son and I had random lights and codes that were nonsense 4x4,abs ,trans fail safe,ect they were caused by voltage regs with high voltage spikes. I found my by using a cigarette lighter attached to a volt meter and driving with the meter on dash. I would randomly get voltage spikes(over 16 and as high as 20 v) 1 or 2 would not effect the car after 2 lights start coming on. Car would go weeks sometimes with nothing and other times you could not drive 5 miles. New regulators fixed both cars. I believe a lot of the random issues are voltage spikes. The spikes cause the control unit to throw codes that are just random. Before you start chasing codes monitor voltage for a couple of weeks and be sure you do not have voltage spikes

[525iT_Feen]

Originally Posted by X53Jay4.8is

when you changed all of the pulleys and tensioners did you notice any reduction in noises generated in the cabin of the vehicle as you drive it?

I don't drive it anymore so I couldn't REALLY tell you but the tensioners were in decent shape for. If I'm being honest, I don't think its any more quiet then it already was inside . I changed them since I was already in there.

Originally Posted by Astrok

Both my son and I had random lights and codes that were nonsense 4x4,abs ,trans fail safe,ect they were caused by voltage regs with high voltage spikes. I found my by using a cigarette lighter attached to a volt meter and driving with the meter on dash. I would randomly get voltage spikes(over 16 and as high as 20 v) 1 or 2 would not effect the car after 2 lights start coming on. Car would go weeks sometimes with nothing and other times you could not drive 5 miles. New regulators fixed both cars. I believe a lot of the random issues are voltage spikes. The spikes cause the control unit to throw codes that are just random. Before you start chasing codes monitor voltage for a couple of weeks and be sure you do not have voltage spikes

Same issue. So it seems this is common. I couldn't really find a thread documenting this exact issue in specifics so I'm glad we've created one for future users with the same issue. Marcadelic - start where Astrok did!