Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
1-when and how did this problem begin?
2-does the security light stay on or flash?
3-does the engine light stay on?if so,can you give me the computer codes?
4-does the security light stay on or flash?
tell me all you can
Ran fine Tuesday. Went out Weds morning to start it and it cranked several times but died each time after about 2 seconds.
At this point, I've now run the battery down trying to figure it out so I can't check the security and engine lights. I'll have to put a new battery tomorrow to check those lights and I'm bringing a scanner home tomorrow to hook up to it.
The weird thing about the security is, we've had this Tahoe for about 7 years. The first 2 years we had to do the security dance where we had to push buttons before turning key but at some point, it would start without us doing the song and dance so we have been starting it just by key cranking for about 5 years now.
you will need to check a few things here
1-scan it and get the computer codes,these will give a clue to the problem
2-check the fuel pressure,these must have no less than 60psi at all times,a weak fuel pump can cause this problem
3-if the security light is on,you may need to do the passlock auto relearn procedure to get it to start
Please ACCEPT my answer so I can get credit for my work.i don't receive commission unless you do ..I'm not always going to be giving you good news,so please don't let this stand in the way of you accepting my answer.it does not cost you more money.we will still be able to communicate.. Bonuses and positive feedback are appreciated!if you are not satisfied with my answer,please do not leave bad feed back,i will gladly opt out and let another expert handle the question.if i have sent any diagrams,please print them.they will only stay on here for an hour or so.PLEASE ASK IF YOU NEED MORE HELP
The following is the Auto Learn Procedure:
Notice: Do not allow the fuel pressure to exceed 517 kPa (75 psi) . Excessive pressure may damage the fuel pressure regulator.
The Vehicle Control Module (VCM) has integrated IC circuits that are fault protected; therefore, if a circuit has failed, the integrated IC may not be damaged. If that is the case, the IC will keep the circuit open until the fault in the circuit has been corrected.When the fault has been corrected, reinstall the VCM and check the circuit. Replace the VCM only if the circuit is still inoperative.Test Description The numbers below refer to the step numbers on the diagnostic tables.
When I dumped gas down the throttle body it squirted out good from the schraeder valve. I also already checked all the fuses with a test light & replaced fuel pump relay. It's 10:45 pm here. I'll tackle it again tomorrow after work and let you know what I get. I'm a just a hard working white boy from Texas.....been a mechanic for 30 years/ASE certified so you won't have to get real detailed for me...just throw me ideas and I'll run with them. I work on a fleet of dodge buses for a living......the Tahoe is my wife's vehicle. I'll chat with you tomorrow night to let you know what did or didn't work with further testing.
it doesn't matter how much fuel comes out of the shrader valve,,,,40psi will shoot a stream,,but,it isn't enough pressure to push the fuel through the poppet injectors,,,so,check the pressure with a test gage
schraeder valve reads 60 psi
engine light doesn't come on
security light stays on
no codes came up on scanner
sense the security light does stay on...did you try the auto relearn procedure?
30 Minute Re-Learn Procedure
i will opt out,maybe one of the other guys has an idea of what is going on here,,,someone will be right with you