Last Thursday, a check-engine icon illuminated in our long-term Chevy Volt’s instrument panel. This happened after two nights alone in our parking structure where the last time the car was left for two nights it fell victim to a vicious attack. We feared that Chilly the Rat had struck again.
We hit the OnStar button and were informed by the adviser of two diagnostic trouble codes regarding battery voltage sensing and electric propulsion control. We were instructed to take the car to the dealer. Last time we got warnings, they were “ABS” and “StabiliTrak,” not “Rat Attack,” so we didn’t know what the real problem might be. The car seemed to perform fine both times.
Thankfully, after a few days at the dealership, we know that the diagnostic trouble codes were false alarms.The technicians performed software updates on nine electronic modules and noted that another update is in development for DTC P0D22. According to our Volt adviser, who made contact today, the fix won’t be ready until May. Should the check-engine light come on due to this code before May, the dealer said, OnStar will be able to wipe the code remotely.
Update: Today, a Volt adviser contacted us and said OnStar is not capable of wiping the code in question remotely. We would have to visit the dealership or wait a day or two to see if the light goes out on its own.
Online Volt forums are full of similar tales, citing overly conservative safeguards that trigger false readings. The software updates serve to bring the diagnostic systems more in line with real-world conditions.
We retrieved the car yesterday and all seems fine. We were without it over the weekend, but there was no charge for the service.