code PO 128 on Mercedes Benz 2008 ML350 4matic what could be wrong?

Question

Check engine light came on did diagnose test code PO128 came up?

Answer 1

HI there

This code is pointing to a problem with the cooling system. Either you are low on coolant or there is a possible issue with overheating. Here is some more info on the code for you.

P0128 - Coolant Thermostat Malfunction

Read more: https://www.autocodes.com/p0128.html

Comments

Ty. Funny you answered me now, I drop Mercedes off 2night at garage. They are replacing thermostat.  Total for labor parts is running me $327. & change.
Does that seem about right?