P0128 2002 chevy silverado

Question

2002 Chevy Silverado, p128 code, not warming up to temp. transmission slipping, oil pressure goes up when I Rev up engine in park, does not have leaks in coolant.

Answer 1

P0128 Thermostat below regulating temperature

This code condition is more of the mechanical condition of the thermostat operation, replacing the thermostat would be the solution for this