I have a 03, 6spd.
Was driving home from work and the truck just died on the road. I cranked the starter many times and finally it started and I made a couple miles. Then it died again. Now it won't start or even try.

The dealer wants $175.00 to look at it and says they don't even make the fuel pump for this truck anymore.

One of the codes says it's a "sentry key immobilizer module"
The codes are the 0628 and 0633

 

P0628 = Fuel Pump Relay Circuit Low, or Fuel Lift Pump Control Circuit Low

P0633 = SKIM Key Not Programmed in PCM


I wonder if the 0633 is the problem causing it to die, and the 0628 was just stored in memory because your lift pump is on it's way out? I think there's been a couple stories of Sentry modules just breaking for no apparent reason.

I also think DC updated the lift pump on your 03. You can get a new one, but it might have to be installed into the fuel tank instead of near the engine.

 

Classic symptoms of lift pump failure.

When you say it won't "try" do you mean it won't crank or it cranks but won't start? Cranks and won't start is probably the lift pump.

Your description and code is exactly what mine did (0628) with LP failure.

jrussel has a good point. If you try the wrong key it will start then stop then just crank. So if the key failed (weird) that could be it. Try your spare key first.


John

 

You also got the "P0633" code when your lift pump died?

 

I edited the post. Please read it again.

I did not get the 0633 code with LP failure. Just the 0628.

Good luck.

John

 

Would you believe it was the key. Somehow the origional key went bad. That's so simple but unexpected.
I put the spare key in and it started right up. Drove just fine. Tried the old key again and...nothing.

Thanks for all the help guys - This is GREAT!!

 

The new key worked for about 2 - 3 hours. Then it failed again. Both times it failed it was on deceleration.

I have a feeling it’s more likely to be security/electronic related than fuel pump related.

I’m trailering it behind a Chevy to the dealer this morning. I hope nobody sees me.

 

I've never heard of a key failure before, but I do carry the extra one with me. I've also seen them on e-bay. But it takes two good keys to program a new one yourself.

I'd hate to get stranded because of the security feature!

It would be funny if it was the LP after all.

Please let us know how it turns out.



John

 

Well, as all of you suggested, it was in fact the pump.

The pump assembly was less than $300.00 and they wanted about $400 for labor.

I lifted the truck box and the replacement was easy...about 3 hours work total. I'm back on the road. The replacement kit was very professional with plug-in wiring, good seals, wire loom, and good directions. Only thing I did different from the directions was to raise the box instead of lowering the tank - so much easier!

The nagging question is - why??? Why did they need to change the location of the pump? It seemed so easy up front... oh well, mark it up to progress.

Thanks Again for all the help!

 

Should have probably upgraded to a GDP as long as you had to do it anyway.