2004 GT - No Start . . . THEFT Light on

Jon S · Apr 20, 2018

My car had been running great. I put it away for the winter last December and tried to start it this morning. Battery has been on a battery tender and was fully charged. Car just cranked and cranked. Normally starts within seconds. Theft light blinks and goes out within 4 seconds of moving ignition switch to on. Cranking the THEFT light stays out, but upon second crank attempt the THEFT light stays on. I cycle the ignition switch so the light is out when I try to start it, otherwise the light stays on. The car is 100% stock and only has 60,000 miles. I've been trying since 11 AM to get it started. No luck. I checked the fuses, full tank of gas, it cranks good and strong. Checked cutoff switch in trunk and hooked up scanner. No codes thrown. Also disconnected battery for 1/2 hour. Thoughts???

Jon S · Apr 20, 2018

Jon S said:
My car had been running great. I put it away for the winter last December and tried to start it this morning. Battery has been on a battery tender and was fully charged. Car just cranked and cranked. Normally starts within seconds. Theft light blinks and goes out within 4 seconds of moving ignition switch to on. Cranking the THEFT light stays out, but upon second crank attempt the THEFT light stays on. I cycle the ignition switch so the light is out when I try to start it, otherwise the light stays on. The car is 100% stock and only has 60,000 miles. I've been trying since 11 AM to get it started. No luck. I checked the fuses, full tank of gas, it cranks good and strong. Checked cutoff switch in trunk and hooked up scanner. No codes thrown. Also disconnected battery for 1/2 hour. Thoughts???

Also disconnected battery for 1/2 hour and locked/unlocked the doors with both key and FOB.

wmburns · Apr 20, 2018

Just wondering. Does the battery run down between starts?

By your own admission the theft light goes out (the first time) after the 3 second "prove out". To me that means that the key was read and accepted. If true that means to me the reason for the crank with no start is not PATS related.

I'm not sure why the theft light comes on the 2nd time. But if looking for an educated guess my vote is a bad ignition switch. IE the ignition switch isn't breaking/making connection needed to reset the PCM.

I don't believe the reason for the no start is PATS related.

What I would like to know is IF fuse F2.2 and fuse F2.8 is actually powering on and off with each key cycle. Same for fuse F2.34. I suspect that one of them isn't.

What would also help to know is IF an ODB2 scanner would "talk" to the PCM on the first and second attempt.

1999-2004 MY fuse panel schedule:
http://www.allfordmustangs.com/foru...r-swap-wont-fire-please-help.html#post2669271

1996+ Crank with no start check list
http://www.allfordmustangs.com/forums/4-6l-tech/336452-1997-mustang-wont-ignite.html#2984838

Jon S · Apr 20, 2018

wmburns said:
Just wondering. Does the battery run down between starts?

By your own admission the theft light goes out (the first time) after the 3 second "prove out". To me that means that the key was read and accepted. If true that means to me the reason for the crank with no start is not PATS related.

I'm not sure why the theft light comes on the 2nd time. But if looking for an educated guess my vote is a bad ignition switch. IE the ignition switch isn't breaking/making connection needed to reset the PCM.

I don't believe the reason for the no start is PATS related.

What I would like to know is IF fuse F2.2 and fuse F2.8 is actually powering on and off with each key cycle. Same for fuse F2.34. I suspect that one of them isn't.

What would also help to know is IF an ODB2 scanner would "talk" to the PCM on the first and second attempt.

1999-2004 MY fuse panel schedule:
http://www.allfordmustangs.com/foru...r-swap-wont-fire-please-help.html#post2669271

1996+ Crank with no start check list
http://www.allfordmustangs.com/forums/4-6l-tech/336452-1997-mustang-wont-ignite.html#2984838

I hooked up an OBD2 scanner and it shows no codes but it is communicating with the PCM I will check the fuses tomorrow. Are they located in the engine compartment or under the dash?

wmburns · Apr 20, 2018

Jon S said:
I hooked up an OBD2 scanner and it shows no codes but it is communicating with the PCM I will check the fuses tomorrow. Are they located in the engine compartment or under the dash?

Just to be clear. The object here is not to just "check" the fuses. If the fuses were blown it would do the same thing every time.

The object is to to confirm that with the key off there is no power in fuse F2.34 and with the key on there is. Repeat for F2.2 and F2.8.

There will be others depending upon the results.

Also want to know if the ODB2 scanner "talks" to the PCM during the 2nd attempt. The details are important as it gives clues where to focus trouble shooting.

From the link provided.
F1=BJB=Battery Junction Box=engine bay.
F2=CJB=Central Junction Box=driver's kick panel

Jon S · May 3, 2018

Disconnected one of the ground wires in front of the battery and turned ignition key to start. All dash lights went out and no crank. Reconnected ground wire and now flashing THEFT light goes out when cranking engine (as it should). Engine ran for 10 seconds and died. Does not restart although cranks and THEFT light stays out. Thoughts?

wmburns · May 4, 2018

Jon S said:
Disconnected one of the ground wires in front of the battery and turned ignition key to start. All dash lights went out and no crank. Reconnected ground wire and now flashing THEFT light goes out when cranking engine (as it should). Engine ran for 10 seconds and died. Does not restart although cranks and THEFT light stays out. Thoughts?

Seems clear to me that the grounds were NOT electrically solid and now they are better. Clearly something has changed.

There's a ton of information given in this thread regarding how to trouble shoot a "crank with no start" issue. Now that the PCM is powering up, how about starting at the top of the "crank with no start" check list and work through it a new?

But starting and running for 10 seconds sounds like the fuel pump isn't running as a good first guess.

Jon S · May 5, 2018

Not sure what you mean by fuse F2.34, etc. all the engine bay fuses have power ignition on or off. Am I missing something? These are the high current fuses 1 - 29.

It seems that replacing my original battery has created this problem. The car is 100% original with zero modifications.

Jon S · May 5, 2018

Jon S said:
Not sure what you mean by fuse F2.34, etc. all the engine bay fuses have power ignition on or off. Am I missing something? These are the high current fuses 1 - 29.

It seems that replacing my original battery has created this problem. The car is 100% original with zero modifications.

UPDATE:

Tried starter fluid to see if I now had spark and it started so the PATS system is fixed. Had a friend bang the fuel tank and it ran on its own. Shut it off after running 5 minutes and it would not re-start. No amount of fuel tank banging worked so assuming the fuel pump is shot. Any way to test fuel pump from underneath?

Neuron · May 5, 2018

Turn on the key while listening for it. Beating on the tank to get it working almost always indicates a bad pump, although a loose connection could theoretically do it too. To get to it you have to drop the tank. Easy to do, the connections were the hardest part for me. I replaced the filler neck gasket too. Mine wasn't even bad(noisy) so instead of getting stranded I changed it.

Jon S · May 5, 2018

Neuron said:
Turn on the key while listening for it. Beating on the tank to get it working almost always indicates a bad pump, although a loose connection could theoretically do it too. To get to it you have to drop the tank. Easy to do, the connections were the hardest part for me. I replaced the filler neck gasket too. Mine wasn't even bad(noisy) so instead of getting stranded I changed it.

Everything I've read points to a bad pump. Tried listening to to open gas filler and total silence. They say topping off tank for storage corrodes the pump contacts. Who knew. Going to get a Motorcraft replacement unless there is a better brand? Thanks everyone for the help!

Jon S · May 5, 2018

Jon S said:
Everything I've read points to a bad pump. Tried listening to to open gas filler and total silence. They say topping off tank for storage corrodes the pump contacts. Who knew. Going to get a Motorcraft replacement unless there is a better brand? Thanks everyone for the help!

Would someone please post a picture of the connector location and which terminals to plug a 12V power source to verify if pump is bad or not.

wmburns · May 5, 2018

The BEST place to test for power to the fuel pump is at the trunk mounted IFS cut off switch. The IFS switch is the device that cuts power to the fuel pump in the event of a hard hit or ruptured fuel tank. Use a known good ground.

Regarding where the fuses are. Just wondering if the information provided regarding the fuse panel schedule was actually reviewed. The URL points to PDF's that show the fuses panel layout and the exact numbering scheme for each fuse panel and what the fuses protect.

From the link provided.
F1=BJB=Battery Junction Box=engine bay.
F2=CJB=Central Junction Box=driver's kick panel

1999-2004 MY fuse panel schedule:
http://www.allfordmustangs.com/foru...r-swap-wont-fire-please-help.html#post2669271

Jon S · May 5, 2018

wmburns said:
The BEST place to test for power to the fuel pump is at the trunk mounted IFS cut off switch. The IFS switch is the device that cuts power to the fuel pump in the event of a roll over or ruptured fuel tank. Use a known good ground.

Regarding where the fuses are. Just wondering if the information provided regarding the fuse panel schedule was actually reviewed. The URL points to PDF's that show the fuses panel layout and the exact numbering scheme for each fuse panel and what the fuses protect.

From the link provided.
F1=BJB=Battery Junction Box=engine bay.
F2=CJB=Central Junction Box=driver's kick panel

1999-2004 MY fuse panel schedule:
http://www.allfordmustangs.com/foru...r-swap-wont-fire-please-help.html#post2669271

Finally figured out the fuse location designations. Checked the BJB fuses and reported ". all the engine bay fuses have power ignition on or off." Thanks again for your help!

Jon S · May 6, 2018

Jon S · May 6, 2018

The BEST place to test for power to the fuel pump is at the trunk mounted IFS cut off switch. The IFS switch is the device that cuts power to the fuel pump in the event of a hard hit or ruptured fuel tank. Use a known good ground.

Could you provide a picture or narrative of which wire(s) to connect voltmeter and power source to to check voltage and additionally provide 12V power to see if fuel pump runs. Thank you.

wmburns · May 7, 2018

The trunk mounted IFS switch is a simple on/off switch. As such it doesn't matter which side is used to test for power.

You can find the IFS switch by reading the car's owner's manual. Also there are labels in the trunk denoting the location of the fuel cut off switch.

There's a green ground bolt located in the trunk. It may be necessary to remove the trunk liner to easily find it. Then:

Get a volt-ohm meter (VOM) set to DC volts.
verify the VOM works by testing at the battery.
back probe the IFS switch with a paper clip or other thin metal. Do not use a lot of force to jam anything into an electrical connector.
attach the red (positive) lead of the VOM to back probe.
attach the black (negative) lead of the VOM to the ground.
turn the key on.
Verify there is +12 volts at the trunk mounted IFS switch.

What to do next depends upon the test results. IF there is power at the IFS switch, then think bad fuel pump.

If there is no power at the IFS switch, then there's a problem upstream that will need more trouble shooting.

Jon S · May 7, 2018

wmburns said:
The trunk mounted IFS switch is a simple on/off switch. As such it doesn't matter which side is used to test for power.

You can find the IFS switch by reading the car's owner's manual. Also there are labels in the trunk denoting the location of the fuel cut off switch.

There's a green ground bolt located in the trunk. It may be necessary to remove the trunk liner to easily find it. Then:

Get a volt-ohm meter (VOM) set to DC volts.

verify the VOM works by testing at the battery.

back probe the IFS switch with a paper clip or other thin metal. Do not use a lot of force to jam anything into an electrical connector.

attach the red (positive) lead of the VOM to back probe.

attach the black (negative) lead of the VOM to the ground.

turn the key on.

Verify there is +12 volts at the trunk mounted IFS switch.

What to do next depends upon the test results. IF there is power at the IFS switch, then think bad fuel pump.

If there is no power at the IFS switch, then there's a problem upstream that will need more trouble shooting.

Heading over to car to try the above. Thank you very much!

Jon S · May 7, 2018

wmburns said:
The trunk mounted IFS switch is a simple on/off switch. As such it doesn't matter which side is used to test for power.

You can find the IFS switch by reading the car's owner's manual. Also there are labels in the trunk denoting the location of the fuel cut off switch.

There's a green ground bolt located in the trunk. It may be necessary to remove the trunk liner to easily find it. Then:

Get a volt-ohm meter (VOM) set to DC volts.

verify the VOM works by testing at the battery.

back probe the IFS switch with a paper clip or other thin metal. Do not use a lot of force to jam anything into an electrical connector.

attach the red (positive) lead of the VOM to back probe.

attach the black (negative) lead of the VOM to the ground.

turn the key on.

Verify there is +12 volts at the trunk mounted IFS switch.

What to do next depends upon the test results. IF there is power at the IFS switch, then think bad fuel pump.

If there is no power at the IFS switch, then there's a problem upstream that will need more trouble shooting.

Have 12 V at the connector on the IFS switch. My son thinks it may be a bad fuel rail pressure sensor He says that I could also tell the fuel pump not to supply fuel and since it starts with the starter fluid and then ran for five minutes he doesn't believe the fuel pump is bad. My feeling is it could be bad contacts on the fuel pump or maybe it is this fuel rail sensor. Thoughts??

General karthief · May 7, 2018

The thought is you have a bad fuel bump

2004 GT - No Start . . . THEFT Light on

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General karthief

wonder how much it would cost to ship you a pair

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wonder how much it would cost to ship you a pair

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