We have replaced the fuel pump, fuel filter, fuel relay( 1 of them) we can't seem to find where the one on the firewall goes if you can help it would be great. We are getting "NO" power to the fuel pump or the coils the van will turn over but will not start. Put a new ignition in it and still nothing. Any ideas would be greatly appreciated.
There are a number of fuses that power the PCM for different functions. Test all the fuses using a test light that reads power AND ground.
June, 8, 2012 AT 4:25 AM
All fuses have been tested all good. We have also changed the crank shaft position sensor and the ignition control module and still will not start.
June, 8, 2012 AT 9:40 AM
All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.
Every engine requires spark, fuel and compression to run. That's what we have to look for.
These are the basics that need to be tested and will give us the info required to isolate a cause.
1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.
2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.
3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.
4) If all of these things check good, then you would need to do a complete compression test.
Once you have determined which of these functions has dropped out,
you will know which system is having the problem.
June, 9, 2012 AT 2:45 AM
Sorry my mom is the one working on my van and what she has is no power to the ignition fuse or the PCM fuse and she said she needs to know where the power for these come from or if its just a bad ground.
June, 9, 2012 AT 10:09 AM
Those fuses are powered by the ignition switch.
June, 13, 2012 AT 12:23 AM
My mom is wondering if you would have a full wiring diagram? She has also found no power to pin 16 in the DLC. Also would like to know if you know whether or not when a new ignition is put in if you can program the keys yourself or do you have to have GM program them? We have put a new ignition in and tried to program the keys but there is no security light on my dash the only light is the pass key light and that wouldn't come on either when trying to program the keys.
June, 13, 2012 AT 12:37 AM
The DLC is powered by the lighter fuse (fuse#15) of the inside fuse box.
ALL KEYS LOST (DOMESTIC)
If the customer has lost all the keys that the VTD module has learned, the PASS-Key III module can be reprogrammed to learn 10 new keys. This procedure will take 30 minutes to complete.
Cut the new key with the mechanical key code for the vehicle.
Insert the new key in the ignition and turn the ignition ON.
The PASS KEY telltale will flash at 1 Hz.
Leave the key ON in this state for 10 minutes.
After 10 minutes, turn the key OFF and then back ON within 10 seconds.
Repeat steps 4 and 5, for a total of 3 ignition key cycles.
After the third ignition key cycle 10 minute time period has elapsed the PASS KEY telltale stops flashing and the new key has been learned. This procedure will reset the valid key code counter to 1. To program more keys, refer to Learn More Keys Mode.
If you are not seeing a security light at all, then you have other issues to get to the bottom of first.
June, 13, 2012 AT 12:54 AM
This is her response the only lights that are in the dash working are the seatbelt and the PDNRL lights up when switching gears. There is no power at the pcm fuse nor pin #16 on the computer dlc hook up. Have good ground there but no power. Also that lighter fuse is good.
June, 13, 2012 AT 12:56 AM
You need a diagnostic tech, not a forum.
June, 13, 2012 AT 1:15 AM
Well thank you for all the help you have given she has gotten further than she would have with your help.