P0128 Toyota -

Question

Anytime p0128 fault code appears, my cooling fan runs without break.

Answer 1

Hi there,

I would start with replacing the coolant temp sensor. If this doesn't resolve the issue then the next step might be the ecm. Something is making the fan run non stop. This could be caused by a sticking thermostat as well, but I would thnk there would be some overheating happening as well.