Prior to 04/25/21 and 08/25/21 I was traveling 60mph on I-205 in the fast lane when my truck went into limp mode. I nearly caused an accident because the truck started shaking, all check engine lights illuminated, and it was challenging to navigate to the right lane and off the highway. This happened on two separate occasions. GM sent a letter dated August 2021 that my truck, ‘equipped with a 6.6L diesel engine, may have a condition that could cause the engine glow plugs to fail.’ The letter gs on to say that GM will cover this issue ‘within 15 years of the date your vehicle was originally placed in service or 150,000 miles (240,000 km), whichever occurs first, the condition will be repaired for you at no charge.’ GM charged me for the repair. The issue is the language in the letter and the word ‘condition’. My interpretation is the ‘condition’ that caused the glow plug to fail is what should be warranted. Nowhere in the GM’s letter ds is state the glow plugs may fail and we will only warranty glow plugs. What caused the glow plug(s) to fail was the electrical connector. The electrical connector is what caused the glow plug to fail. The glow plug by itself was not the ‘condition’ that caused it to fail, the ‘condition’ was a faulty electrical connector. GM must be held accountable to cover this safety defect. I have attached all documents pertaining to this incident. Please advise.