View Full Version : I'm Making Progress..But.

07-02-2006, 03:38 PM
Hey Guys,
Seems im making progress...But im still getting code#542.Fuel pump circuit open, EEC processor to motor ground. Any ideas on how to get this fixed

07-02-2006, 03:50 PM
Have you used the wiring diagrams from the previous post? Do you have power at the inertia switch? Has the switch been triggered?

07-02-2006, 03:56 PM
Yes i used the previous drawings.I have power to the switch and the switch hasnt been tripped.....Ideas?

07-02-2006, 07:47 PM
Ideas anyone?

07-03-2006, 06:43 AM

07-03-2006, 08:52 AM
Hav you checked your ground connections?

07-03-2006, 08:02 PM
I checked what ground wires i could see and they seemed ok.What area should i be looking in?Im hoping that there is a way to get this done SOON....

Charles G
07-03-2006, 08:17 PM
I just spend days troubleshooting a no Fuel Pressure problem. Here is how it works and it sounds like your answer is fairly straight forward. I have a 92 EECIV in case yours is different but I doubt it.

You turn key to start, which tells EEC to ground the fuel pump circuit, on mine this is pin 22, which happens to be the same lead that goes to the test connector, if you have any service manual (Haynes or Factory) it will show you this connector. When you ground the far left terminal on this connector, labeled in diagrams fp, and key is on, fuel pump should run and pressure go up as normal. This proves fuel pump works, etc. Now without the this terminal jumped to ground. The EEC grounds the fuel pump via internal connection to complete the circuit, but it must get enough voltage about 12volts from the red wire circuit 361, supplied by the IRCM, two common open grounds are the IRCM itself (black wire, I think it is pin 3 on connector) and there is a round connector right next to battery which gets corroded from battery inside, if either of these have bad ground, no fuel pump action...good luck.

Charles G
07-03-2006, 08:20 PM
If so it is bad ground circuit 57 black wire I mentioned out of IRCM connector, or the connector near battery, check out this article on Taurus...where I got my hint...


07-04-2006, 08:26 AM
Thanks Guys,
Im going to try and solve the problem today.....Charles thanks for the input and link...I hope thats the problem.I had to take a couple hours off from working on the car.Temper seemed to be rising and my patients were spent.So maybe after a good night sleep i get it done.Thanks again guys.I'll keep ya updated.

07-04-2006, 01:52 PM
I followed the directions and found everything is grounded and still together.I still cant get it to start.:mad: :mad:

07-04-2006, 02:41 PM

07-04-2006, 04:16 PM
When you get in and turn the key to the run position do you hear the fuel pump run for about 2 or 3 seconds then turn off.Does the pump run at all,do you have fuel pressure.There is a schrader valve on the fuel rail on the driver side beside the blower nose section.

07-04-2006, 04:31 PM
Hey Guys,
First off i would like to thank all you guys for your help.If any of you find yourself out this way the wings and beer are on me.Now to the problem.
Here is what i have so far.
When i turn the key on i hear the pump come on.
I checked the fuel at the schrader valve and its good.
I have power going to the fuel pump relay(which i replaced with a new one)
The inertia switch is not tripped and is getting power.
All my grounds seem to be good.
I changed the Cannister purge solenoid and when i did it seemed like it wanted to fire,it kinda stumbled a little and then nothing.
Im still coming up with code#542.Fuel pump circuit open, EEC processor to motor ground.
And last but not least i am so p***ed off with this car,im ready to snap.Its been down going on 2 weeks......

07-04-2006, 04:39 PM
Did you ever take your EEC out or unplug anything that you put back together? I dont remember how many times Ive taken off my EEC and when I put it back a couple pins in the wiring harness connector were smashed and the car wouldnt start. :rolleyes:
There is also a ground wire on the EEC in the kick panel.

- Dan

07-04-2006, 04:45 PM
Kick Panel?....as in behind the glove box?

07-04-2006, 06:42 PM
The kick panel is located below the glovebox and towards the outside of the car,on the passenger side the computer is located there.You can always try and disconnect the negative terminal of the battery for about 15 min to reset the computer.It will go into relearn mode that way,just in case your car was trying to compensate for something that is not there anymore.

07-04-2006, 06:43 PM
Below the glove box, on the right side .. the little kick panel, that you would take off to get to the EEC. If you havent taken it off the wires should be fine. There are a few ground wires down there.

- Dan

07-04-2006, 06:47 PM
Hey Guys,
I have not touched the kick panel...yet.You say disconnect the neg from the battery.Well i have had it un hooked while i work on it,it has been unhooked for for days.I only hook it up when im trying to start it.Should i leave it connected? for re learning?

07-04-2006, 08:34 PM
No if you have already taken the neg terminal off then that wont fix anything.Just sometimes if the car has had many issues it tries to adjust to adapt to compensate for them.So you still have the same code,if you can clear the codes and see if that helps.

Charles G
07-05-2006, 06:23 PM
when you replaced canister purge solenoid you touched the red wire which feeds it, and the MAF sensor and one or two other things, the most important thing that circuit does is trigger the EEC to ground the fuel pump internally if voltage is about 12 volts, if it is lower, fuel pump is not grounded and no pressure. You can measure the red wire voltage coming out of IRCM which is the same circuit. When you say you checked fuel at Schrader valve and it is good was the pressure good, or did you just find gas there. When you changed the canister purge solenoid you also touched part of harness that comes out of IRCM, check that black wire out of the IRCM, peel a little with a razor and ground it chassis ground, if relays are chattering, in key on position. Based on your voltages ok all around fuel pump, it can only be the fuel pump ground which is done by EEC internally or you can short test connector lead (also pin 22 of EEC). Keep us posted and good luck.

07-05-2006, 09:08 PM
I took a few pics....maybe that will help?

Charles G
07-05-2006, 10:06 PM
If you have fuel pressure at the Schraeder valve should be around 40psi, check with Fuel Gauge, you have eliminated a lot of things: fuel pump is ok, power to fuel pump is ok, fuel filter is ok all wiring from firewall to fuel pump is ok.

If you dont have fuel pressue, you need to try to manually turn fuel pump on by grounding the terminal of the test conector as suggested by someone in an earlier thread.

If you can manually turn on fuel pump by grounding this connector, than the problem is the ECM is not automatically grounding the fuel pump and completing the circuit.

07-05-2006, 10:27 PM
Hey Guys,
Seems im making progress...But im still getting code#542.Fuel pump circuit open, EEC processor to motor ground. Any ideas on how to get this fixed

Codes 542 and 543 can come up because the EEC has lost the ability to read the circuit.

I fixed a 91 SC that had either 542 or 543 by replacing the O2 sensors. I had a 17X something code also due to the bad O2 sensor. The 91 up EEC has the O2 sensor heater circuit wired into the fuel pump cicuit grounds or something so a bad o2 sensor heater can cause the 54X codes. It is possible that the O2 sensor itself is still working but the heater inside has failed. There is a fuse for the O2 sensor heaters in the fuse box. You maight want to pull that fuse to see if the code goes away. You can drive the car without O2 Sensor heaters.


07-06-2006, 09:59 PM
Problem has been found??...After a lenghty time checking wires and eec,ircm,and every ground and connection.I went down the wrong path after i found fuel at the schrader valve.It was just gas left over and i didnt have pressure.Now i have a couple of questions.What are the wires running to the pump through the floor into the top of the tank?.1 is black(ground) 1 is pink w/black stripe(power) 1 is yellow w/white stripe i dont now what this is.1 is orange i dont now this one either.Can anyone tell what these are?.
And i need to know where the fuel pump is extactly and what fuel lines are running along the top of the tank.
My plan is to do the fuel pump from inside the car this weekend.And replace the floor i cut out with 18ga 303 stainless.

07-07-2006, 02:58 AM
Its easy to drop the tank and swap out the pump, why you whanna start cutting holes?

07-07-2006, 04:21 AM
I figure someone should do it.This way i will have access to it the next time it goes.I will talk pics as i go and someone so in the future they can be used for reference.Can anyone tell me?.....

07-07-2006, 07:13 AM
Be careful and make sure you don't cut into the tank. :eek: I can understand wanting an easier access to the pump, without dropping the tank.

Kevin Varnes
07-07-2006, 07:52 AM
It seems we are having the same problems. Have you tested the actual pressure on the rail or just for the presence of fuel? I'm getting the exact same code with a no start and I have good fuel pressure on the rail.

Charles G
07-07-2006, 04:18 PM
What year is your car? I have diagrams with all colors of wires from '92 send me and email if you still need which are which. [email protected]