Fuel Problem
- Thread starter bullitt1939
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wmburns
SN Certified Technician
Turn the key on but do not start/crank. Confirm that the theft light goes out after a 3 second "prove out". If not, STOP and find out why.
Cycle the key off/on/pause several times without cranking. Do you hear the FP run each time? Now crank the starter. Does the theft light come on during cranking? If it does, STOP and find out why.
Test for +12 volts at the IFS with the key on. If no voltage, the CCRM is bad or fuse F1.14 is blown.
If there is +12 volts, more tests are needed to confirm.
Tell us about any mods.
Cycle the key off/on/pause several times without cranking. Do you hear the FP run each time? Now crank the starter. Does the theft light come on during cranking? If it does, STOP and find out why.
Test for +12 volts at the IFS with the key on. If no voltage, the CCRM is bad or fuse F1.14 is blown.
If there is +12 volts, more tests are needed to confirm.
Tell us about any mods.
The car is pretty much stock. I have an offroad x pipe, mil elimators, 40 series flowmaster, and k&n air filter. I checked the theft light it goes off as it should. The switch in the trunk is down. However, if I checked the voltage correctly I am not getting any voltage to switch in the truck with key on. The fuse #14 under the hood is good. I have had the car 6 years and it eats TPS sensors. I just changed it thinking that was the problem again. The fuel pump is not kicking on when I turn the key. The car will run as long as my foot is on the gas petal. The minute I let up it starves and kills. What I am puzzled about is if it is the fuel pump since it is electric it shouldn't be getting any gas even if i push the petal correct? I am just trying to figure out if it is the fuel pump, fuel filter or some other relay. I do remember I parted out an 01 GT last year and there was a fuel pump driver module mounted in one of the front fender (I believe it was the driver's side). Could this be the problem? Any help would be greatly apprecated. I would like to drive her once in a while. Thanks.
wmburns
SN Certified Technician
If there is no voltage to the IFS, the the problem is UPSTREAM from the IFS. You are wasting your time looking for a problem in the FPDM or fuel pump itself.
There MUST be +12 volts to the IFS at all times the key is on. If not, the CCRM is bad, the fuel pump fuse is bad, there is a bad control circuit fuse, there is a wiring fault between the CCRM and the IFS, or the PCM is bad.
DOUBLE check fuse F1.14, F2.34, F1.26. Also double check the voltage measurement at the IFS. Make sure that a known good ground is used.
There MUST be +12 volts to the IFS at all times the key is on. If not, the CCRM is bad, the fuel pump fuse is bad, there is a bad control circuit fuse, there is a wiring fault between the CCRM and the IFS, or the PCM is bad.
DOUBLE check fuse F1.14, F2.34, F1.26. Also double check the voltage measurement at the IFS. Make sure that a known good ground is used.
Ok wmburns. What next? I have no power to IFS (0.0 volts on meter). Fuses check out ok. I know it is upstream. It is also not the FPDM I had an extra one popped it in just cause it was an easy elimation. Fuel pump is not kicking on. How do I test to see what component is bad?
I might also add the car had been sitting for about a month when this mess started. I went outside to crack it and after a few times got it running fine then it started this again. I am assuming something was on the verge of going out and then just finally went out completely. Thanks.
I might also add the car had been sitting for about a month when this mess started. I went outside to crack it and after a few times got it running fine then it started this again. I am assuming something was on the verge of going out and then just finally went out completely. Thanks.
wmburns
SN Certified Technician
Please perform all tests and post the results. Tests are to help narrow down problem source. Make sure that a known good ground is used for all voltage tests.
Be on the look out for rodent damage.
The fuses have a test point that is accessible without removing the fuse. Measure the key off voltage at each test point of fuse F1.14 (20a). Post. If voltage is not present on BOTH test points, STOP and find out why.
Measure the key on voltage at the alternator main B+ terminal. Post.
Measure the key on voltage of Red ignition circuit. This can be tapped at any COP or the radio interference capacitors. Post. If no voltage, STOP and find out why.
Remove the right front wheel and plastic fender liner to access the CCRM.
Measure the key off resistance from CCRM pin#18 (BK) back to battery negative. Post. Likely there is a ground problem if more than 5-7 Ohms.
Measure the key off voltage of the CCRM pin#11 (LB/OG). If no voltage, STOP. You failed because fuse F1.14 likely is bad.
Measure the key off voltage of the CCRM Pin#10 (BK/OG). If no voltage, STOP. Fuse F1.26 bad.
With the key on, measure the voltage at CCRM pin#12 (RD). If no voltage, STOP. You failed because fuse F2.2 likely blown.
With the key on, measure the voltage at CCRM pin#5 (DG/YE). If no voltage, STOP. REPLACE CCRM. If voltage, likely there is a wiring harness problem.
Note:
F1=BJB=Battery Junction Box-located left hand engine bay (near battery)
F2=CJB=Central Junction Box-located driver's kick panel area
Be on the look out for rodent damage.
The fuses have a test point that is accessible without removing the fuse. Measure the key off voltage at each test point of fuse F1.14 (20a). Post. If voltage is not present on BOTH test points, STOP and find out why.
Measure the key on voltage at the alternator main B+ terminal. Post.
Measure the key on voltage of Red ignition circuit. This can be tapped at any COP or the radio interference capacitors. Post. If no voltage, STOP and find out why.
Remove the right front wheel and plastic fender liner to access the CCRM.
Measure the key off resistance from CCRM pin#18 (BK) back to battery negative. Post. Likely there is a ground problem if more than 5-7 Ohms.
Measure the key off voltage of the CCRM pin#11 (LB/OG). If no voltage, STOP. You failed because fuse F1.14 likely is bad.
Measure the key off voltage of the CCRM Pin#10 (BK/OG). If no voltage, STOP. Fuse F1.26 bad.
With the key on, measure the voltage at CCRM pin#12 (RD). If no voltage, STOP. You failed because fuse F2.2 likely blown.
With the key on, measure the voltage at CCRM pin#5 (DG/YE). If no voltage, STOP. REPLACE CCRM. If voltage, likely there is a wiring harness problem.
Note:
F1=BJB=Battery Junction Box-located left hand engine bay (near battery)
F2=CJB=Central Junction Box-located driver's kick panel area
Ok here are the first few results. I have 12 volts to both sides of fuse F1 14. I also have 12 volts to all fuses under the hood in the fuse box.
Next I have 11 volts to B+ terminal on alternator.
Here is where I ran into the first problem on the sheet so far. I have 0 volts to the radio interference capacitors. I don't know why, but if you could shed some light on this could this be my problem.
Next I also don't have any volts to some of the fuses inside the car. The fuses are good because they work in other spots of the fuse box and I have 11-12 volts to them. Could there be a reason I am not getting power to the whole inside fuse panel? It is selective like every other one are so. Could I have have a fusable link that is blown? If so where would this be located.
This little problem is really starting to puzzle me. I don't have time to take the tire off because I have to go to work, but I ran into a problem the step before take off the tire.
Thanks for all the info.
Next I have 11 volts to B+ terminal on alternator.
Here is where I ran into the first problem on the sheet so far. I have 0 volts to the radio interference capacitors. I don't know why, but if you could shed some light on this could this be my problem.
Next I also don't have any volts to some of the fuses inside the car. The fuses are good because they work in other spots of the fuse box and I have 11-12 volts to them. Could there be a reason I am not getting power to the whole inside fuse panel? It is selective like every other one are so. Could I have have a fusable link that is blown? If so where would this be located.
This little problem is really starting to puzzle me. I don't have time to take the tire off because I have to go to work, but I ran into a problem the step before take off the tire.
Thanks for all the info.
wmburns
SN Certified Technician
Double confirm that fuse F1.3 has power on both sides. Not a bad idea to test all fuses in the BJB.
Confirm power in fuse F2.34. If no power, then the ignition switch is BAD.
If power in and out of fuse F2.34, proceed with checks of CCRM.
Confirm power in fuse F2.34. If no power, then the ignition switch is BAD.
If power in and out of fuse F2.34, proceed with checks of CCRM.
Ok all fuses under the hood have 12 volts. I also have 11 volts to fuse 34 in the car on both sides. I only have power to about half of them in the car, but 34 is good. All my gauges, lights, radio, power windows, and mirrors work. My door locks work sometimes and sometimes they don't. I was thinking the actuators were going out and they may be or this may be related to my electrical problem. Could it still be the ignition switch if I have power to the fuse? I won't have time to pull the tire for a few days, but I guess that is my next step. I am trying to figure out why I don't have power to all fuses in the car. Also why would I have no power to radio interference capacitors?
wmburns
SN Certified Technician
Not likely. Fuse F2.34 is powered from the ignition switch.
The RED engine ignition circuit is powered from the CCRM. Fuse F2.34 supply the coil power to latch the CCRM relays. So if F2.34 is powered, the CCRM should power up the PCM, fuel pump, and ignition.
Perform the rest of the CCRM tests and likely you will know why. However, it does look like the CCRM is at the heart of the issue. Of course a bad CCRM ground could also cause these EXACT symptoms.
Ok this car is about to drive me to drinking. I can't get any volts out of the wiring harness for ccrm. I had the key on trying to test things then all of a sudden my radio goes out, my inside light comes on and stays on, and odometer goes to all dashes. The gauges still come on though. I checked the fuses under the hood again and they all have about 8 volts now. I think my battery is getting weak though cause i have been having the key and radio on while messing with it the last few days. While I was messing with the ccrm harness I touched something and sounded like it was kicking something under the hood on. Also and I suppose to have a prone for all slots. When I pulled it off ccrm I noticed some prongs are not there. I am not sure if it was like this from the factory, but it was tight when I pulled it off. Thanks for all the good info.
wmburns
SN Certified Technician
You haven't completed the CCRM tests as requested. The tests are needed to narrow down if the problem is BEFORE the CCRM, with the CCRM, or after the CCRM.
Post back when you have the results. Otherwise, replace the CCRM.
Good luck.
Post back when you have the results. Otherwise, replace the CCRM.
Good luck.
I tested the specific pins listed above. I can't get voltage out of any of them. However, when one pin on the meter touched a certain pin it sounded like something was tryin to kick on. All fuses have voltage under the hood. I checked them all again. Also the theft light stays on and blinks now, which it was not doing before. Is this due to ccrm being removed?
wmburns
SN Certified Technician
If the CCRM is removed, then NOTHING down stream will get power. It makes perfect sense to me that the theft light is blinking with the CCRM removed.
The tests were meant to be preformed with the CCRM installed.
You did not post the results of the CCRM ground measurement.
I attempted to create tests that would confirm the proper inputs the the CCRM. So if the correct input are present and no output, then doesn't the CCRM have to be bad?
The tests were meant to be preformed with the CCRM installed.
You did not post the results of the CCRM ground measurement.
I attempted to create tests that would confirm the proper inputs the the CCRM. So if the correct input are present and no output, then doesn't the CCRM have to be bad?
wmburns
SN Certified Technician
Eject, eject, eject!
MacGyver alert.
Can anyone say paper clip? Use to back probe the connector.
MacGyver alert.
Can anyone say paper clip? Use to back probe the connector.
Ok after doing a little more research there is only power to the inertia switch and CCRM for 2-3 secs once turning the key. Is this true? If so how can I test it by myself? I don't have anyone to help me at the moment and this could be why I am not getting voltage to the components. I have also tried a code/scan tool and nothing is coming back. Thanks.
wmburns
SN Certified Technician
Please re-read previous posts. Specifically stated that the IFS is powered at all times the key is on. Otherwise there is a problem.
Not sure there is anything else I can do here. Given the best expert advice I have. Going nowhere.
*EDIT* in post #3 it was mentioned there is no voltage in the trunk IFS. Mixed in with the symptoms is "will run if I keep my foot on the gas".
The question/answer about voltage at the IFS is vital as it sets the troubleshooting direction. If no voltage at the IFS, it is not possible for the fuel pump to run. Nor is it possible for the motor to run.
If there is voltage at the IFS, then it's a waste of time to look for problems upstream of the IFS (CCRM, ignition, or fuse).
Not sure there is anything else I can do here. Given the best expert advice I have. Going nowhere.
*EDIT* in post #3 it was mentioned there is no voltage in the trunk IFS. Mixed in with the symptoms is "will run if I keep my foot on the gas".
The question/answer about voltage at the IFS is vital as it sets the troubleshooting direction. If no voltage at the IFS, it is not possible for the fuel pump to run. Nor is it possible for the motor to run.
If there is voltage at the IFS, then it's a waste of time to look for problems upstream of the IFS (CCRM, ignition, or fuse).