Car Doctor Q&A: No Start. Now What?

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A dead battery in a Chevy pickup left for a considerable length of time can require reprogramming before the truck will start.

Q. I’m hoping you can help me. We have a 2002 Chevy 2500 pick-up truck and it sat most of the year due to a rusty brake line problem. We have that problem fixed but now the truck won’t start. The battery was dead and we recharged it but when you try to start the truck the anti-theft light comes on.

We checked the computer with a scan tool and came up with code P1626. The truck started perfectly before it sat waiting to get repaired and this code looks like a complicated repair. Do you have any easy suggestions?

A. I would start with a check of the basics before diving onto computer issues. For any engine to run it needs fuel, spark and engine compression. I would look for any wiring that could have become damaged while sitting as well as fuel issues.

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Once the basics have been checked, then it is time to look at the GM anti-theft system called PASSLOCK. There is a simple reprogramming procedure. Try cranking the engine and then leave the key in the on position for 10 minutes-no more no less and then turn the key off for 10 seconds. At this point the security light should have stopped flashing, now attempt to start the truck.

If that sounds confusing, check out the video of the procedure. It’s pretty straightforward:

It has been my experience that for one reason or another it can take a couple of tries to get the reprogramming to stick. Now once the engine is running turn it off and restart the truck and allow the system to “learn” the key. The security light should be out and the engine should run normally.

John Paul is public affairs manager for AAA Southern New England. A certified mechanic, Paul tests dozens of new cars each year and also hosts a radio show on AM 950 and 550.