same as others, car starts right up then dies. did this for a while then would run fine ....now cant get it running at all ...

I can run fuel pump from relay and see that the fuel pump is running in the "crank" position then stops running when the ignition switch goes to the on position and it does not run in the on position of the ignition switch.. I can keep the car running if i keep the key in the crank position (the starter kicks out )

I did the ignition switch repair per mr Curlee's awesome instructions put the ignition switch back in and its doing the same thing, the pump wont come on in the on position


could it still be in the ignition switch...im getting no codes and its a 2000 c5 coupe.....

 

See your PM.

 

You need to check the voltages coming out of the ign switch. The fuel pump won't stay running unless the car does. Is it possible that it is a effect and not a cause? If your PCM doesn't see oil pressure, most PCM's will kill your fuel pump.

 

bottom line is the fuel pump is not turning on when the ignition switch is in the "ON" position....it should turn on for the 2-3 seconds...the pump only turns on when the ignition switch is in the "CRANK" position and will stay on if it keep it in that position..thats why it starts then shuts off when the key returns to the "on" position..

.im still thinking ignition switch as the pump should be turned on for the 3 seconds till it starts, in the "ON" position, but hate to throw money at things when im not 100% sure...even though i cleaned it up (the ignition switch) it still may have a problem with it

 

A seasoned forum member like you should know that this is not the case. Just read the dozens of threads about "no oil pressure" yet the car runs.....

 

Do you have a service manual? You can find out in short order what's wrong by using going through the wiring diagram......

 

I had the same issue and cleaned switch but that was temporary. I had to eventually replace switch and everything has been fine since. I also double checked VATS system disable. For the approx $80 it was worth the frustration and labor involved.

I went through a long trouble shooting process and should have looked for Bill's post prior rather than after. The forum is a great resource with some very knowledgeable participants.

 

This is pretty easy to check, since you are already familiar with the ignition switch...even better.

After reviewing the wiring diagram, it looks like you want to check continuity between contact "A" of connector "C1" and contact "B" of connector "C2" of the ignition switch itself. If there is a bad contact, you should read continuity in the "crank" position, and no continuity(or very high resistance) in the "on" position.

For reference: The harness side connector "C1" should have a red, orange, yelllow wires, and connector "C2" should have red, brown, pink wires.

 

i am getting continuity on both the on and the crank position,,,,

 

well i got a link to this page cause i went thru same issue. he ended up taking his to the dealor so as soon as wee gert word i will let you know. we traced everything in fuel system and seemed fine. so wheere thinking it the ignition switch/ vats system so where hoping it be covered under the bulletin/warranty lol

 

Ok, for the sake of being thorough, let's check the rest of the contacts:

On the switch, check continuity between the following:

contact "A" of C2 and contact "B" of C1 ( start only)

contact "A" of C2 and contact "C" of C1 ( on only)

contact "A" of C1 and contact "C" of C2 ( on only)

 

check
check
check (also on this one im getting continuity on B also of C2)

 

I know this is a dumb question, but are you checking with the ignition switch disconnected from the harness while doing the continuity test?

Eric D

 

yes, and with me and electricity and drawings , nothing is a dumb question

 

ok, so unless there is something intermittent in the switch, the contacts check good.

I'll PM you my number.

 

Could it be a VATS issue? or even a CLB problem?

There are a couple reasons why an engine will start and then be told to shut down so don't get tunnel vision, if the ignition switch contacts check out then it's time to move on and check the next item down the line.

The fuel pump gets a signal to run from the PCM, the PCM sends this signal to the fuel pump when it gets a valid ignition signal that shows the engine is running. In other words, you turn the key on and the pump runs for 3 seconds and shuts off, then you turn the key to crank and as the engine cranks the pump is signaled to come on again, then once the engine starts the PCM should see an ignition signal and tell the fuel pump to keep operating.

 

How are you checking the switch???? Are you using an OHM Meter? What is the "RESISTANCE" of the contacts that you are testing. Good "CONTINUITY" tells me nothing.

You can have continuity but if there is too much resistance at the contact point, there wont be enough current to run the pump. Post the resistance of each of the switch terminals that lucky131969 listed for you.

Bill

 

Good point Bill, I should have been more clear on that.

 

Sorry Bill and Lucky,,,, I didnt see the additional posts by you guys till today.......thanks to lucky and indirectly to Bill i have solved this problem ....and also thanks to the guy that i was helping put in a shifter for allowing me to borrow his ignition switch.......

By going by Luckys help it did start to look like the switch wasnt the problem......and by reading the many posts on this and other issues by Bill I started to understand how the switch and the fuel pump worked together etc....heres what happened...

I borrowed my buddy's ignition switch since i had his car apart while installing a C6 z06 shifter and low and behold the same thing...the pump wasnt turning on for the 3-4 seconds in the on position..

Ok so i know that the pump is good since i can jump the relay and get it to come on and also by powering it up from the battery to the relay point i can get the pump to come on and that the ignition switch isnt the problem....

but it wouldnt come on when the key was turned to the on position....so my feeble brain and a lot of reading about grounds on these cars from Bill's post made me start looking there....I tried the ground pack on the front under hood passenger side (naturally the harder one to get to) and that looked ok, cleaned it up, put it back together and same thing "nothing"

so now i go to the easier one to get to on the front drivers side and all i did was loosen it and move it a little and retighten it and then try it out...and low and behold, the pump comes on and it starts up and has been running fine all week... I took it apart and cleaned it and again it didnt look bad and wasnt corroded, i cleaned the contact it makes on the rail and it has been working great...


now for the confusion, according to the prints it looks like that is one that isnt for the fuel pump but may be for the pcm...im in work and dont have the prints with me but i thought the ground for the fuel pump was in the back somewhere on the frame rail although i could not find any ground packs in the back of the car at alll


bottom line i guess is that for anyone having a no fuel pump turning on when the key is in the on position and the car starts then dies, is to first check that ground...the one under the hood on the drivers side near the headlight connection plug on the frame rail.......

again thanks for your help luck and to anyone else that replied and thanks again to mr Bill for all his writeups on electrical stuff in here on these cars...


jack

 

I've done all that and changed out the I switch. Stll have the problem intermitantly

Throws the following codes

U1064
U1096
U1016



This is driving me nuts!