What makes a 4L60E limp mode?
What makes a 4L60E limp mode? "Limp mode" is usually caused by no power to the trans from the ecm. Check all the wiring & connectors to be sure they are clean & tite. Check for voltage from the ecm & at the transmission. What to do if your transmission is in limp mode? Make sure that you are somewhere safe. Make sure that the engine has been off for at least 5-10 minutes. This will give the engine computer a few moments to sort anything out. Go ahead and verify that the transmission is still in Limp Mode. Sometimes...