Code Not Stored In System

[smrio]

2005 GMC Sierra 4.3 v6

Well I ran across some problems while accelerating on the freeway. Passing other cars the engine light came on. It's been doing this at 39,000 miles, now I'm at 57,000. The light stays on and the next day it isnt there. I had time this week and went to AutoZone to check the code, but nothing was stored in the truck cpu memory.

This usually occurs when accelerating when I'm at 70 mph and need to pass another car. The engine sounds ok, I notice no rattling or anything out of the ordinary, but the light has to come on for some reason. Then there's the code, why doesnt the code stay in the system memory?

[Patrick H]

Not sure what kind of equipment Autozone uses, but if you take it to a regular shop they'll be able to read memory codes and freeze frame data, which should store the trouble (fast) code.

[dlstewart01]

If its an anti-lock brake code or a b code, they can't read it. It takes a tech 11 type scanner.