Pontiac Repair: code p0128 on a pontiac aztek 2004, pontiac aztek, engine control module

Question
Have a code p0128 .need help with this.thank you.

Answer
Hi there Francisco:

well it's 1 of 2 things it either has a thermostat and or it's low on coolant. either thing can cause the code to set. it sets because the engine control module (ECM) doesn't see the correct amount of run time to ratio of engine temp increase. so the thermostat could be stuck open or open too soon or it's low on coolant will cause a similar issue same end result the lamp is on. good luck :-}