Possible PATS problem?

Derek31

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Apr 20, 2020
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I got a 2000 gt 5 speed. Guy got rid of it because he got tired of messing with it. Car has a new motor with less than 5k on it and is unreliable to start. Ford had diagnosed that the gauge cluster was faulty so got a new one, programmed it and drove it back from the dealership, parked it and it wouldn’t start the next day. Drug it back to the dealership and replaced the PCM, programmed it and drove it back home, next day wouldn’t start. Tried a new CCRM and nothing. It will turn over but won’t fire. Fuel pump won’t even kick on. Keys were supposedly reprogrammed during both trips to the dealership. All this is in a weeks span. Anybody have any suggestions besides letting a scrap yard fix it?
 
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wmburns

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Aug 14, 2009
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Turn the key on but do NOT crank. Does the check engine light come on? Does the theft light come on and then go off after a 3 second "prove out"?

Does the cluster display the mileage at initial key on.

Does the check engine light go out when the motor is cranked?

1996+ Crank with no start check list

Do you have an ODB2 scanner? If you did it might make short work of this problem.

ForScan ODB2 scanner w ELM327 USB

Why is an ODB2 scanner important? Because IF the motor isn't starting because of a PATS issue it will also set a PATS specific DTC code in the PCM.

After the ODB2 scanner answers the question about if there's a PATS DTC, the scanner can be used to check other sensors needed to start the motor.
 

Derek31

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I didn’t look to see about the check engine light but the theft light flashes quickly and the odometer just reads - - - - - across the board. Fan kicks on with key on but the pump doesn’t. And wouldn’t all pats systems been reset after having a new cluster and pcm put in with the keys being reprogrammed to both?
 

wmburns

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odometer just reads - - - - - across the board. Fan kicks on with key on but the pump doesn’t
Please review the crank with no start check list. The cluster displaying all dashes is a dead giveaway that:
  • The PCM is NOT being powered up. Either no power or no ground.
  • The PCM is dead/bad
This is not a PATS problem. The Blinking theft light is a SYMPTOM of the problem.

Checked all the fuses under the hood and their good.
Review the part in the crank with no start check list about checking for power in and out of fuse F2.34, F2.2, and F2.8. Note, This does not mean check the fuses. This means to use a tester and actually test for power into and out of the fuses with the key on.

1999-2004 BJB CJB fuse panel layout:
 
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Derek31

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Apr 20, 2020
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So I checked the fuses, number 35 which handles the PCM, speed control servo and the ABS module is getting 9 volts coming in with fuse removed and less than 1 with fuse in. Does anybody have a wiring schematic so I can trace this thing down?
 

Derek31

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Apr 20, 2020
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So I checked the fuses, number 35 which handles the PCM, speed control servo and the ABS module is getting 9 volts coming in with fuse removed and less than 1 with fuse in. Does anybody have a wiring schematic so I can trace this thing down?
This was fuse box under the dash
 

wmburns

SN Certified Technician
Aug 14, 2009
5,810
499
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Houston Texas
So I checked the fuses, number 35 which handles the PCM, speed control servo and the ABS module is getting 9 volts coming in with fuse removed and less than 1 with fuse in. Does anybody have a wiring schematic so I can trace this thing down?
My wring diagrams indicates fuse F2.35 is only hot when the brake pedal is depressed. So your test results should be "odd" when the brake pedal isn't depressed.

Did you use a test light to "load" the circuit or are you using a VOM meter? If using just a VOM meter that would also explain WHY the readings are higher than expected open circuit valves.

In any case, fuse F2.35 is not the reason for the crank with no start symptom.

What are the results of the key on power in and out test of fuse F2.34, F2.2 and F2.8. The exact combination of who has power and who doesn't will give clues where to focus next.

Hint: no power in fuse F2.34, focus on the ignition switch. Good power F2.34 and No power in both fuse F2.2 and F2.8, focus on the CCRM.

Even better. CONFIRM that the black wires at the PCM are able to carry a Strong grounding current. In the voltage drop video, notice how Eric O used a high current light bulb to load down a heavy ground to correctly test the current path.

Howto perform charging system voltage drop test

If you are interested in getting a copy of the Ford Service DVD for your own I maybe able to help. PM if interested.
 

wmburns

SN Certified Technician
Aug 14, 2009
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Houston Texas
I tried a new CCRM already and fuel pump still won’t kick on
The whole reason for testing the input/output of the fuses was to confirm the basic operation without having to change parts. IF there's key on power in/out of fuse F2.2 and F2.8 THEN the CCRM is basically working.

NOTE the "crank with no start" check list was included in the 2nd post (my first reply).

Does the cluster Odometer still display all dashes? If the PCM is not communicating with the cluster (all dashes) THEN it should be expected that the fuel pump won't run. The details matter here.

You have checked the fuel pump fuse in the Battery Junction box (BJB=F1) right? What about the rest of the fuses in the BJB?

To continue with testing we need to know IF the trunk mounted IFS switch has key on +12 volts on both sides of the switch.

Also need to know if there is "always on" power in and out of fuse F2.21. This is the PCM keep alive fuse.
 

Derek31

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Apr 20, 2020
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I had already put the ccrm on before asking questions, was just throwing money at it. But so I checked the IFS switch and has power on both ends. The fpdm has power going to it from the ifs. Wondering which wires lead from the fpdm to the fuel pump and which ones are coming from the pcm to the fpdm.
 

wmburns

SN Certified Technician
Aug 14, 2009
5,810
499
164
Houston Texas
Does the cluster Odometer still display all dashes? If the PCM is not communicating with the cluster (all dashes) THEN it should be expected that the fuel pump won't run. The details matter here
You did answer the questions from my previous reply.

The fact there's power to both sides of the IFS switch "proves" that the CCRM is working as it's supposed to. But again it should be expected that the fuel pump won't prime unless the PCM is functioning enough to "command" the fuel pump to run.

Wondering which wires lead from the fpdm to the fuel pump and which ones are coming from the pcm to the fpdm.
IMO you are wasting your time focusing on the fuel pump until the PCM operation has been CONFIRMED good.

But if you insist on further fuel pump trouble shooting the wire colors are RD/BK BN/PK.
 
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