Fuel cut off while driving

[thatsnninety5]

Was driving on the highway when my cars fuel was cut off, car was still on and had power but not running. pulled over and it would crank but you could hear it was getting no fuel, i checked the fuel pump fuse and it was still good, check the inertia switch in the trunk and it didnt trip, I even tried purposely popping it up and starting it and it didnt work, so pressed it back down, tried cranking again and nothing happened, I hooked up my scanner and it was weird because I tried doing an engine off key on test about 7 times and every time I got the error “test complete, malfunctioned detected” or “it seems the test is not supported” this was either the forscan network, recently it has been feeling as if my transmission was slipping, it has been feeling like it goes into neutral while driving sometimes, or when coming to a stop it feels like the gear slips so when I have to start moving again it finally catches the gears after pressing the gas, does the same in reverse, took about 40 seconds to go into gear but im beginning to think my fuel pump was going causing it to seem as if my trans was slipping. I also have blue colored corrosion on my positive battery cable, I have not yet checked fuel pressure but I imagine i cant check it with no power going to the pump. Give me your thoughts, with everything I said google said it could be my CCRM but I replaced that about a year ago. It couldve went but who knows. TIA!

 

[96blak54]

Go around back, pull the inertia switch plug and feed the fuel pump 12v just to see if itll kick it over and run. This of course assumes everything about the fuel system is good, relay, fuses, wiring, etc. If the pump is good, strong, at least youve narrowed down the ccrm possibility

 

[thatsnninety5]

How do I put 12v to it? Do I have to drop the tank? And if it works does that mean the CCRM is the problem? Also as far as wiring what wires go to the fuel pump, how should I test them?

Go around back, pull the inertia switch plug and feed the fuel pump 12v just to see if itll kick it over and run. This of course assumes everything about the fuel system is good, relay, fuses, wiring, etc. If the pump is good, strong, at least youve narrowed down the ccrm possibility

 

[cobrajeff96]

The inertia switch is simple. The two wires on that plug are +12v input from CCRM and a +12v output directly to the pump, just a simple passthrough. So you can just key-on probe either wire with a simple voltage probe light stick thingy or a multimeter. If no voltage present, then it's either CCRM fuel pump relay is gone or there is an open break on that 12v wire from CCRM to inertia switch. If +12v is showing up at that inertia switch junction, then likely it's the fuel pump that died or there is an open break on the +12v output line from inertia switch to the pump or the inertia switch itself is at fault (which is unlikely) but that can be tested for with a multimeter. You'd just unplug it like the previous test, set a multimeter to either an ohm (resistance) test or better yet the diode check function with audible tone indicator and just simply touch both leads to both inertia switch terminals simultaneously (being careful not to touch the MM leads to one another) and if it beeps then it's a good switch. If no beepy, the switch is gone.

 

[ttocs]

also check all your fuses both under the hood and dash. Don't bother with the manual trying to figure out which ones, it takes less time to inspect them all to be sure.

 

[SnakeBit!]

how much gas in the tank when it happened?

 

[thatsnninety5]

how much gas in the tank when it happened?

Just filled it up so more than 3/4 tank

 

[thatsnninety5]

The inertia switch is simple. The two wires on that plug are +12v input from CCRM and a +12v output directly to the pump, just a simple passthrough. So you can just key-on probe either wire with a simple voltage probe light stick thingy or a multimeter. If no voltage present, then it's either CCRM fuel pump relay is gone or there is an open break on that 12v wire from CCRM to inertia switch. If +12v is showing up at that inertia switch junction, then likely it's the fuel pump that died or there is an open break on the +12v output line from inertia switch to the pump or the inertia switch itself is at fault (which is unlikely) but that can be tested for with a multimeter. You'd just unplug it like the previous test, set a multimeter to either an ohm (resistance) test or better yet the diode check function with audible tone indicator and just simply touch both leads to both inertia switch terminals simultaneously (being careful not to touch the MM leads to one another) and if it beeps then it's a good switch. If no beepy, the switch is gone.

I checked the voltage of both of those wires, I got nothing but Im afraid I was doing something wrong because even went testing the switch for continuity there was no beeping, tried my scanner again and still couldnt run the test “test interruption” so I cant test if the cooling fan works either, unless theres a way I can without my tester. Also the wire on my plug wires was completely off so I have the replace it

 

[ttocs]

it only has power on it for 5 secs after you turn the key on. You might need someone to turn the key on while you test. Or as he said trace the wire that goes down to the pump and throw 12v on it and you should hear the pump prime

 

[cobrajeff96]

That disconnected wire is an EMI suppressor. Not a huge deal.

Are you using a multimeter to test the voltage or a simple single-lead voltage probe?

 

[thatsnninety5]

That disconnected wire is an EMI suppressor. Not a huge deal.

Are you using a multimeter to test the voltage or a simple single-lead voltage probe?

I have a test light but the probe is to big to fit in the sensor to test it, I didnt want to break it so I just used my multimeter that had skinnier leads on it

 

[cobrajeff96]

Just make sure that when you do a voltage function test, the key is on.

When you do a continuity check, there should be no power going to the test piece.

 

[thatsnninety5]

Got around to test the 12v wire from the battery to inertia switch, had my dad turn the key while I tested for voltage and got nothing, Im going to replace the CCRM.

 

[cobrajeff96]

Tested both wires? Did you ground out the alligator clip while taking the reading?

There is a chance it might not be the CCRM, but rather any portion of that output wire from the CCRM to that inertia switch. Unlikely, but still possible.

You might be able to save the CCRM and not toss it aside. Mark Olson at Accutach can potentially diagnose and repair it for you and that way you'll have a spare. Good chance it's just the fuel pump relay that burned out inside and everything else is still ok.

 

[ttocs]

There are two wires at the inertia switch, you should see 12v on both of them and seeing voltage on only one could mean a bad switch.