2003 idling issue
The problem comes and goes - it very much the old vapor lock on older cars. I remember reading something about a small filter possibly clogged but then the issue went away so I never followed thru.





Have you ever cleaned your MAF and Throttle body/blade?
Look at the PCV rubber boot that connects to the manifold. They rot and leak vacuum.
Battery Voltage on the door modules. Hmmmmm, That indicates that you have a low or weak battery. The DTCs usualy pop directly after engine cranking. If you clear them and they come back, you need to figure out WHY voltage is dropping LOW.
The reason why it a history DTC, is once you stop cranking, the voltage returns to normal. YES,,, history DTCs are important too.
I hae seen a dirty ignition switch also cause the issues that you are seeing. I would check all the other stuff before you dig into the ignition switch
Things to do
Clean the MAF wires (Use MAF Spray cleaner).
Clean the Throttle body throttle blade.
Insure that the ducting between the MAF and TB is sealed tight.
Check the PCV Valve rubber components and other vacuum lines for rot and or leaking.
Actually Measure with a DC Volt meter the battery during cold cranking and see how far the battery output voltage drops low. For the DCM to report low, it has to be around 9.5 VDC -10 VDC
Last but not least, you can clean or replace the ignition switch if all the above doesnt help. Check out this post:
- C5 ignition Switch repair - http://forums.corvetteforum.com/c5-t...ch-repair.html
Bill





You can measure the voltage on the fuel pump fuse (two test slots on the fuse to chassis ground . You should see FULL Battery voltage on that fuse when the key is ON.
Bill
My car is stock. I bought some MAP cleaner and plan to clean it when I return. Great information guys ( and gals)!!!
My car is stock. I bought some MAP cleaner and plan to clean it when I return. Great information guys ( and gals)!!!

I didn't even know you could still get a battery where you had to add water, maybe for a lawn mower. You need to get rid of that thing and get a real battery designed for the car.





