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Chris (aka- Moose)
Chris (aka- Moose), Technician
Category: Ford
Satisfied Customers: 47275
Experience:  16 years experience
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2000 ford Tureas 3.0 no 5v to any of the sensors. Checked

Customer Question

2000 ford Tureas 3.0 no 5v to any of the sensors. Checked all grounds. Computor seems to be working fine. Took the comutor out and probed the tan and red wire that suplys 5v to all sensors .05v. Not .5. I discounted all the coils the starter and altinator. Check all grounds to relays and checked relay for pcm.theft light turns on for 3 seconds and turns off.
Submitted: 5 months ago.
Category: Ford
Expert:  Chris (aka- Moose) replied 5 months ago.

Welcome, I'm Chris (aka Moose), my normal schedule online is around lunch and after dinner till early morning.

To diagnose this concern you have to unplug all things that get the 5 VREF. Then see if the 5 volts are back. If so then it is one of the sensors to blame. IF the voltage is not back then cut the vref wire after the pcm. If there is still no voltage then it is the PCM to blame.

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Thanks for using Just Answer, Chris

Customer: replied 5 months ago.
I cut the wire at the pcm no 5v.
Customer: replied 5 months ago.
Checked all the grounds and supply to the pcm. Left the 5v wire cut. Reprogrammed the key. Still no 5v
Expert:  Chris (aka- Moose) replied 5 months ago.

Time for a new PCM as long as all the powers to the PCM are good, which I assume you meant when you said the computer seem to be working.

Customer: replied 5 months ago.
Ok before I change the the pcm with a new one. I checked all the suplys amd i checked the grounds. The resistance on the chasy grounds were at 6.0 the resistance on yhe motor was 1.0 so i started unpluging fuses and relays. The resistance dropes down to 1.0 when i unplug the ignition fuse. I disconnected the starter and alt with the fuse in and no drop. Only after unpluging the ing fuse
Customer: replied 5 months ago.
Ok plugged the ing fuse back in and unpluged the junction box fuse. F101 and f103. And the resistance dropped back to 1.0. I still have the starter and the alt unpluged. And the pcm is unplugged.
Customer: replied 5 months ago.
Can you send me a diagram of all the. Power pins the pcm should have when key is on and all the grounds. And what do you think could be the reason for the resistance increase. And how i might fix it.
Expert:  Chris (aka- Moose) replied 5 months ago.

How are you taking your resistance reading Ex: PCM unplugged testing a ground wire at the PCM to the ground terminal on the battery?

Here is a diagram. https://dl.dropboxusercontent.com/u/90220402/SEPCM.pdf

Customer: replied 5 months ago.
Negative terminal to ground wires on pcm unpluged. And pluged in same resistance reading, 6.0 key on 1.0 key off. Also same readings on any ground point on the chasy. And the pcm dose pick up codes. Any sensor i unplug picks up on a KOEO test.
Expert:  Chris (aka- Moose) replied 5 months ago.

All PCM grounds should show 0.0 reading. You may want to clean the engine, and body grounds from the battery. Even at 6 ohms it still pretty much a good ground.

Customer: replied 5 months ago.
cleaned all the grounds on the motor frame ran a new ground wire. The only time the resistance gos up is when the key turns on. Which tells me that theres some short somewhere. Just changed the pcm again and checked all the power and gronds. Still doing the same thing. No spark no injection pulse. Thefts light turns off. The only code that runs is the ECT out of range.
Expert:  Chris (aka- Moose) replied 5 months ago.

You're still getting no 5 VREF to sensors?

If you OHM test the PCM ground wires from there connection on the vehicle to the battery is there resistance there as well?

Using a scan tool is the PCM getting a cam and crank sensor signal when cranking?

Customer: replied 5 months ago.
What id like from you if you can. Is a chart of the pin out of what pins should have power at key on and key off. And with the computer unpluged. Theres a short some where. Still trying to find it.
Whats going is
No spark no inj pulse
No 5v ref to any sensors.
One code. Temp sensor out of rangeThings ive done.
Checked and cleaned groungs.
Checked power to pcm.
Replaced pcm.
Key on grounds on pcm blk/w have 12v out of pcm when i cut them. The grounds had .05 when grounded to frame.
Main pcm ground blk has no v when i
Cut the blk/w grounds.
No theft light.
Checked ckp sensor for wires tuching. There not.
Customer: replied 5 months ago.
What i think is happening is theres a sensor or module that has a ground source from the pcm to activate it but the sensor or ground is shorted and sending 12 back into the pcm and frying it or just cosing the pcm to not turn on.
Customer: replied 5 months ago.
Also i opened up the pcm. And there appears to be no burnt out resistors or chips. Usly when i replace a bad pcm i smell a burnt electrical smell and can see something fried in it
Expert:  Chris (aka- Moose) replied 5 months ago.

https://dl.dropboxusercontent.com/u/90220402/175taurus.pdf

I need to know if you have a 2 or 4 valve engine?

Expert:  Chris (aka- Moose) replied 5 months ago.

Hello again Chris here,

  1. I have to assume you were not pleased with my help, because you have not replied or rated the post.
  2. What would you like to do regarding your question now?
  3. Do you still need help? Please reply I want you to get equal to or more than what you paid for.
  4. This post is coming up on the 7 day mark where it times out. That can prevent me from being able to post answers to your replies.

Thanks Chris

Customer: replied 5 months ago.
Its a 24v.
Expert:  Chris (aka- Moose) replied 5 months ago.

pin 3, 24, 25, 51, 76, 77, 103 ground

pin 55 power all the time

pin 71 power with the key on

Customer: replied 5 months ago.
Thank you. What do you think of this so far. Have you ever see anything like what im describing?
Expert:  Chris (aka- Moose) replied 5 months ago.

If all powers and grounds are good, the VREF wire is cut and not providing 5 volts out with the key on then it has to be the PCM.

Customer: replied 5 months ago.
Ok so computors unpulged key on. 3, 6, 24,24,51, 76, 92 are gronded. 1,2,6,11,12,20,26,27,28,36,46,52,53,54,55,56,67,69,73,74,75,78,81,83,88,93,94,95,96,99,101. All have 12v when keys on. Key off computors unpluged 30,55, have 12v
Expert:  Chris (aka- Moose) replied 5 months ago.

So what I gather from your list.

There is no ground on pins 25, 77, and 103?

There is no power on 71?

Customer: replied 5 months ago.
77, 103 are blank spots. 25 dose have a good ground at .4 key off and 2.5 key on
Pin 71 is an empty slot.
Customer: replied 5 months ago.
Date 04/00 vin 1fafp56s5yg214308
24v 3.0
Customer: replied 5 months ago.
71 has power key on
Expert:  Chris (aka- Moose) replied 5 months ago.

I can not make since of your replies. 71 is empty, 71 has power?

Are there pins on the PCM for pins 77-103?

Are you sure your looking at the diagram correct by matching the wire colors to the pins?

Customer: replied 5 months ago.
71 dose have 22v at key on
Customer: replied 5 months ago.
12v correction
Expert:  Chris (aka- Moose) replied 5 months ago.

Other than the PCM missing some grounds then all looks within specs.

Customer: replied 5 months ago.
Ive replaced it twice now. And its done the exact same things. And yes 77 and 103 are not options
Expert:  Chris (aka- Moose) replied 5 months ago.

I have carried this as far as I can. I can opt out and let another help.

Customer: replied 5 months ago.
Ok. I know this dosnt make since to me.
Expert:  Chris (aka- Moose) replied 5 months ago.

Opting out now, best of luck

Customer: replied 5 months ago.
Id like to get a refund for this.
Expert:  Chris (aka- Moose) replied 5 months ago.

Use the contact us link at the bottom of the page to do that.