Hello all I have a 2002 l300 wagon it starts with ease runs 3-5 seconds but dies it is showing no codes and fuel pressure is 45 lbs on the rail I am at a loss here any help would be much appreciated Tia Mayhem.

 

What's the status of the security light when this is happening?

Is it 100% of the time?

Have you checked the air intake including filter for obstructions?

Was this a gradual onset issue or did it suddenly occur?

 

Ok this came on all the sudden car ran great until earlier this week, air filter and fuel filter are good and security light comes on when you first turn on the car but turns right off.

Oh and I should mention fuel pump is less than 10 months old and less than 5k on new timing belt and water pump.

 

You haven't changed keys have you? If so, maybe it's a valet key and not a chipped one? I'm just asking, because I don't know. Perhaps you need a new key? Do you have an extra one you can try instead?

 

Thanks for all the replies so far but no it's the same key that's worked before this problem arose, It's kind of baffling to me drove car home with no issues shut it off for the night next morning car starts right up and dies 3-5 seconds like clockwork and it starts up like a new car no extended cranking or such????

And still no codes I have an extensive set of tools and a good scanner is one of them.

 

Really sounds like security system issue (Passlock II). Ign Cyl, , BCM, and PCM all work together to make sure no one is stealing the car.


As I understand it (crudely)

• Sensor contact with the ignition cyl to ign switch must be made
• The PCM and BCM are handshaking with a passphrase that must match on both ends

 

Hey guy's a quick update I tried the relearn process the other day to no avail, so I decided to jack up the car a try to get a look a the crankshaft sensor it was plugged in had the breather box off and a buddy started the car and low and behold it runs just fine wait a minute the MAF is unplugged it shouldn't run right? Well I shut off the engine and hook up the MAF sensor and stat the car and fires up and dies after 3-5 seconds hmm? Ok so I purchase a new MAF sensor and car is like new, why did it not have any codes ? Well I don't know why either but for now it's running like a champ.

 

I don't have a clue why the MAF didn't throw a code, but I'm pretty much a dumbass. The main thing is you've got her up and running now, so congratulation. You are tenacious like bulldog!

 

Thanks for the help, and if you have any diesel questions especially 6.5 and lly Duramax give me a shout thank you all for the help.

 

The only thing I can think is that since the car was always being started from cold, the PCM was in open loop mode and trying to run a semi standard air fuel mix, but probably checks the MAF every couple seconds to update the air fuel mix.
The first time it checked the (bad) MAF sensor reading, it screwed the mix and the engine cut out.


Commentary: NO CRITICISM of your efforts, troubleshooting or any of that kind of stuff. Just me kinda "closing out" the thread with a "what did we learn" from your experience.
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I've found, by experience (as in I need to figure this out NOW), that with non-trivial OBDII codes, you REALLY need to track down the specific manufacturer's service information to determine WHAT SPECIFIC CONDITIONS have to be met to throw each code. It helps you quickly narrow down 10 possible causes to one or two explanations that are educated high probability scenarios.


Same concept as "why won't my I/M readiness monitor test for {whatever} run?"
Have you met the criteria for that test to run? "I dunno". GO FIND THE DRIVE CYCLE DOCUMENTATION and educate yourself.


I will certainly agree that that no code situations for someone without real time data monitoring capabilities (MYSELF INCLUDED) can be a nightmare, depending on their level of knowledge, expertise, and hands on experience.


But ultimately there's a reason you did not throw a MAF code. If you dig deep enough into the criteria for all the MAF codes, I'm confident that whatever the bad MAF was sending to the PCM, ALONG WITH OTHER CONDITIONS, was not messed up badly enough to meet the ALL the criteria for setting a MAF code. Frustrating as hell, but also reality.


With a real time data scanner, the MAF output signal could have been monitored during cranking and non cranking and would have given an idea if the observed output was expected for those conditions. What would you expect to see at rest? during cranking? You'd have to go find that information to decide if the readings were acceptable.


How would you know to check the MAF sensor as being a/the culprit?
A-1) You verified air, fuel, spark and compression.
A) ruled out every other 1st level check of sensors/conditions that might prevent your car from starting
B) Experience -- you've seen this happen on 20 of the same model Saturn


Rube's very simple comment that holds true: You need air, spark, fuel, and compression if ya want it to run.


This is not necessarily straightforward w the newer cars, addl sensors, computer controlled this that and everything.


You ran into a perfect situation where your car had all four, but STILL wouldn't run.
Why not? Because the bad MAF sensor told the PCM incorrect information, the PCM torqued the air fuel mix to the point it would not stay running---but apparently didn't meet the criteria for throwing a MAF code.


So I'd like to create Rube's Axiom, in honor of his contributions to this site, to the lives of many on this site, and, well, just because.


Rube's Axiom:
Ya gotta have air, fuel, spark, compression--and the PCM's gotta agree-- or you ain't goin' nowhere. And that burning smell is your starter, dumbass.