Ah the famous P0128.....It's 1 of 2 things. If your fan is not engaged constantly (would sound like an airplane or big rig everytime you step on the gas) and is working properly, that rules out the fan clutch. The other common problem is the thermostat. Replace the thermostat and the code will go away. Engine temperature needs to be at 210 degrees on these engines. If the fan clutch is constantly engaged, it's cooling the engine off constantly and won't get up to 210 fast enough. If it's the thermostat, it's stuck open and isn't allowing the coolant to properly heat up in time.
SOURCE: GMC Envoy w/ code P0128
Start at $89 right off the bat just for diagnostics and then depending on what they find that is causing that fault, at LEAST one hour labor, plus parts....I would say $250 is a good ballpark figure....looking up your fault code now.
1,511 views
Usually answered in minutes!
×