I need some help. My 2005 H2 has been acting weird lately. The temp gauge sits on 160 when I knowthe engine is warm, intermittently shoots up to 210. The engine looses power (hesitates) and the trans shifts hard. Over the weekend I got a check eng light, scanned it and got a code of p0128. Cleared the code so far it has not come back however the gauge is sill all over the place and the engine and trans are surging. Any suggestions?

 

It sounds like you are low on Dex cool. Temp sensors cant read hot air so if the cooling system is low you will get erratic readings like that. If you didn't have the other symptoms I would say maybe the temp sensor or gauge is faulty. One more thing is to make sure your battery terminals are clean and tight.

 

can you tell me where the ECT is located?