P1258 GMC -

Question

2003 GMC Envoy

Code P1258, vehicle is over heating. What needs to be replaced? Thermostat, water pump, or censer?

Answer 1

P1258 Engine over temperature condition

How the cooling fan operation, when the engine is at a higher than normal operating temperature the cooling fan clutch engages more to have a more cooling effect. With the engine off the cooling fan should not readily spin it should have resistance, if it does not the fan need more inspection. If the engine has ran hot , you need to replace the thermostat, what happens is the thermostat looses it characteristic durung a overheat event so it alway recommended the thermostat be replaced. and  also check for coolant leaks