P0128 Cadillac -

Question

Replaced thermostat,coolant temp sensor& coolant by-pass valve engine lite still goes on and says p0128

Answer 1

Hi there,

I would suggest checking the wiring. Here is a list of other possible issues for this code.

P0128 CADILLAC - Engine Coolant Temperature Below Thermostat Regulating Temperature

Read more: https://www.autocodes.com/p0128_cadillac.html