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Discussion Starter · #41 ·
Get a pipe and tap the starter body. These cars are notorious for getting a build up of oil INSIDE the starter and when it builds up it causes a no-start when you turn the key. Tap the starter body (not the relady) a few times and see if that helps. I had that very issue a year ago and tapping it got me started in 2 seconds. BE CAREFUL if you leave battery attached not to ground out anything--- BETTER still-- pull negative off the battery just in case.
The car cranks when you put power to the relay. I don't think it is the starter. The problem is no power to the control side (pin #86) of the relay. The pink wire from Pin 86 of the relay going to the PCM is making connection. How can i tell if my PCM is getting power and ground?
 

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Good point.

But the Check Engine Light comes on when you turn the Ignition to RUN, right? The CEL is possibly the only light in the instrument panel controlled by the PCM directly.

To be absolutely sure, you could take off the connector of the Fuel Pressure Sensor:

Pressure-Sensor-Connector-1.jpg

and check with a volt meter the voltages on the pins of the connector. With the Ignition to RUN the outer two pins should carry 5.04V and the middle pin 0.04V. The regulated 5V voltages come from the PCM. You could have tested the Throttle Position Sensor and the DPFE sensor as well because they are connected to the PCM in exactly the same way, but the FPS is the easiest to reach.

Of course, with a scantool you would immediately know the status of the PCM :rolleyes: , because without power to the PCM the communication would fail.
 

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Also, when you turn the Ignition to Run you clearly hear the fuel pump in the back being activated. I think the PCM does this too in models 2000 and later. It is pin 80 of the PCM.
 

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Also, when you turn the Ignition to Run you clearly hear the fuel pump in the back being activated. I think the PCM does this too in models 2000 and later. It is pin 80 of the PCM.
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The fuel shutoff after priming at "key on" has been standard since electric fuel pumps bagan. Keeps you from fueling a fire when the engine is not running.
Or a major leak. No reason for fuel if the engine is not running. Once the starter is keyed, pump turns on again as long as you crank or it starts.
-chart-
 

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The car cranks when you put power to the relay. I don't think it is the starter. The problem is no power to the control side (pin #86) of the relay. The pink wire from Pin 86 of the relay going to the PCM is making connection. How can i tell if my PCM is getting power and ground?
I thought the car didn't crank. But doesn't crank when you turn key to start? Someone else mentioned the fuel pump winding up sound. Did you also check to see if the little button for the fuel safety is depressed? It is in the trunk, right side. I understand what you are asking about the power, but I am not certain that you would have a reading there all the time. If you know anyone with a Taurus or Sable, perhaps you can side-by-side them and do the same wire trace and confirm the correct state for that wire.
 

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I do not know if this is what you need to know, but if I need to relieve pressure on my son's 2001 I press the sh andut off in the trunk then crank the engine. This uses the fuel in the lines. The engine will just barely catch then die. The fuel pump is unable to get power and I do not need to pull a fuse.
 

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Discussion Starter · #47 ·
The fuel shutoff after priming at "key on" has been standard since electric fuel pumps bagan. Keeps you from fueling a fire when the engine is not running.
Or a major leak. No reason for fuel if the engine is not running. Once the starter is keyed, pump turns on again as long as you crank or it starts.
-chart-
I hear the fuel pump go on as soon as I turn the key to on.... Is this normal? it runs and doesn't stop, even if I am not cranking or turning the key to crank. It just turns on and doesn't stop as long as the key is in the rn postion. Is this normal?
 

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Discussion Starter · #48 ·
I thought the car didn't crank. But doesn't crank when you turn key to start? Someone else mentioned the fuel pump winding up sound. Did you also check to see if the little button for the fuel safety is depressed? It is in the trunk, right side. I understand what you are asking about the power, but I am not certain that you would have a reading there all the time. If you know anyone with a Taurus or Sable, perhaps you can side-by-side them and do the same wire trace and confirm the correct state for that wire.
The car doensnt crank with the key. sorry for the confusion. When I take out the relay for the starter and put power to pin 86 with a jumper wire, the car cranks. I hear the fuel pump. I have not checked the fuel safety button. Will do that now.
I do not know anybody else with a Taurus/sable sadly.....
 

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Discussion Starter · #49 ·
ok, well the inertia switch in the trunk is good. It was pressed down. Is this only looking for a on off signal?
 

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Discussion Starter · #50 ·
Ok, now im confused. I have this diagram, and i wanted to see if the TRS was getting power. It is, through the brown/pink wire, and its coming out of the TRS through a tan/red wire when turning the key to crank. The weird thing is it is also grounded when not turning the key. The tan/red wire coming from the TRS goes to pin 85 of the relay, where 2 tan/red wires go into pin 85. Is this normal for both to be there?
When i set my multimeter to continuity, and go from body ground to pin 85 and hit the key, my multimeter goes all funny.... is this normal?
 

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Fuel pump running constantly with key in RUN position but engine not running is often a sign of a failed PCM.
 

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Thanks for the diagram. Is that from the Ford Electric Diagrams manual?

Together with this diagram of the pinout of the PCM

pcm_connector1.jpg and pcm_connector2.jpg

that I copied from this thread, we now know how this works: pin 86 is connected to the PCM pin 44 in stead of the ground. So the ignition works all the way up to pin 85 but it depends on the PCM to pull 86 to the ground to activate the relay. Behind pin 44 of the PCM is a transistor and that is why your multi-meter behaves a bit odd.

I guess the Tan/Red wire runs to the PCM (pin 4) because that connection is called "Power, Hot in Start with Park or Neutral" which pretty much describes it. What the PCM should do when it sees that pin powered is to pull pin 44 to the ground. But it doesn't.

This is the long version of the short answer that Jeff K already gave: replace the PCM.

Of course you could still:
  • Test the correct arrival of the Tan/Red signal at pin 4 of the PCM connector (a test light will do).
  • Check the continuity of the Pink wire from PCM connector (pin 44) to relay pin 86.
but together with the fuel pump and the THEFT light issue, I'm afraid this is just putting off the inevitable.
 

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Discussion Starter · #54 ·
Fuel pump running constantly with key in RUN position but engine not running is often a sign of a failed PCM.
Ok, maybe i have a bad PCM. I kind a hope so, so i can stop diagnosing this thing. Any good way or place to take the module to to test it? I also dont know if the pump runs while running, as i have not been able to get it running
Thanks!
 

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Any good way or place to take the module to to test it?
It typically comes down to buying a "refurbished" PCM that comes with two uncut keys that are pre-programmed into the PCM (say $200). I think "refurbished" here means cleaned and reflashed (so it has the latest software). You could also buy a new one from Ford but that might be 3 times that price.

It could be that reflashing your existing PCM solves the problems, but having that done should be substantially below that $200 or it would not be worth the try. And I don't know who does that.
 

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Discussion Starter · #56 ·
It typically comes down to buying a "refurbished" PCM that comes with two uncut keys that are pre-programmed into the PCM (say $200). I think "refurbished" here means cleaned and reflashed (so it has the latest software). You could also buy a new one from Ford but that might be 3 times that price.

It could be that reflashing your existing PCM solves the problems, but having that done should be substantially below that $200 or it would not be worth the try. And I don't know who does that.
Can Forscan test the PCM?
Thats what ill do before spending any big money
 

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I don't know much about Forscan. I know it has features for the PATS (Passive Anti Theft System) so it might report a problem in that area. It can also show the status of all kinds of sensors, such as the TRS. It can certainly not reflash the PCM. What I understand is that only licensed Ford dealers can do that.
 
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