Why did my car shut off while driving it

Electrical problems with the Malibu For the past 4 years, my daughter’s 2011 Malibu (started at 65,000 miles) has had problems with the car shutting down and refusing to move forward or backwards. The car would die while driving but start back up and run fine after a few minutes. The power steering / ESC lights would come on along with the chimes sometimes ringing 3 times. The power steering would no longer work. To resolve this dangerous problem, the car has been to the dealer 6 times, who replaced the steering shaft torque sensor at no cost under the 150,000 mile warranty (applies to most Malibu’s without extended warranty coverage) due to defects in the power steering system. What makes this situation so exasperating is that it is intermittent. The car will run well for 6 months and then shut down while driving. It will go into a “limp home” mode and barely move. Other times, it stops moving altogether. We were never able to get the car to malfunction while at the dealer so the mechanics said they could not fix it until the car acted up for them. On several visits to the shop, the dealer discovered there were than 7-9 troubleshooting codes, all with “loss of communication” for the power steering, ESC, ECM, EBCM, acceleration, etc. (Note: None of these codes were detectible on my personal code reader, only the dealer’s more expensive machine.) All were major system failures. The dealer was not able to come up a definitive malfunction and made several recommendations to replace the Transmission Control Module (TCM) for $1,500 but they could not be sure this would fix the problem, so we declined to throw more money at the problem. After extensive reading, I became convinced the problem was a poor battery ground even though the battery was replaced and the cables all looked good. I replaced both battery cables and cleaned all 4 ground connections (battery, engine, radiator housing, and firewall) and added dielectric grease to improve the connections. Since we were also getting signs of power steering failure, I took the 3 electrical connections apart (they are under the dash on the driver’s side of the car’s interior) and added dielectric grease to improve connectivity. But most likely, a poor ground in the engine compartment was the bigger problem. It has now been 1 month since the work was done and the car is running perfectly. I will not know for sure for another 5 months if the battery cable replacement and cleaning the other ground connections solved the problem. But I do agree with several other reponders on the forums, this is the most likely cause of this terrible problem. The moral of the story is the Malibu (and many other new cars) and very susceptible to even slight variation in voltage. With a poor ground, even a bump in the road might be enough to reduce the voltage for a moment to knock out one or more major electronic systems. It is not like the old days where a bad ground cable would cause the car to crank slowly or not start at all. Newer cars are capable of starting and running fine for a while before the electronic systems start to fail. Don’t always expect to find any error codes since our car did not throw any codes the first time or two to the shop. It was only the 3rd time did the many “loss of communication” codes show up, leading us in the right direction.