1992 Taurus Fuel Pump / PCM

[elvisload]

92 Taurus 3.0L DOHC

NOTE: JUST ACQUIRED THIS CAR WITH ZERO HISTORY ON IT. ALL I KNEW WAS IT HAD QUIT RUNNING, WAS AT PEP BOYS, AND THEY 'SAID' THEY PUT A COMPUTER IN IT (THEY DIDN'T FEEL OBLIGATED TO MENTION THE FIRE THEY CAUSED). WHEN I GOT IT HOME (BARELY) I NOTICED FIRE RETARDANT ALL OVER THE TOP OF THE ENGINE, AND THE EEC TEST PLUG WAS MELTED, BUT NO OTHER VISIBLE SIGNS OF FIRE DAMAGE.

A symptom of starting and dying immediately, has turned into no start at all. I assumed fuel. Checked inertia fuel pump safety switch in trunk, the button was down. Changed fuel filter. Removed tank and fuel pump. Pump runs fine with power from the battery. Used continuity tester at the inertia switch and discovered no power there. Clearly, no power is getting back to the fuel pump. I've read this post from John, re 93 Sable:

http://www.automotiveforums.com/vbul...76#post3234476

With great replys from Rod, but it's for a 93 Sable

HELP!

[shorod]

Originally Posted by elvisload

92 Taurus 3.0L DOHC

A symptom of starting and dying immediately has turned into no start at all. I assumed fuel. Checked inertia fuel pump safety switch in trunk, the button was down. Changed fuel filter. Removed tank and fuel pump. Pump runs fine with power from the battery. Used continuity tester at the inertia switch and discovered no power there. I see 12 numbers on the harness connection at the PCM. 1 thru 6 are upper and lower pairs then 7,8,9,10,11 are single wires, then 12 is another upper and lower pair. Clearly, no power is getting back to the fuel pump. I've read this post from John, re 93 Sable:

http://www.automotiveforums.com/vbul...76#post3234476

With great replys from Rod, but it's for a 93 Sable, and the numbers on the PCM connertor go to 24? Rod? John? HELP!

I posted a response to your question at the above link. If you are really looking at the PCM, you are looking at the wrong connector. The info I posted was for the CCRM module above the radiator.

-Rod

[elvisload]

Rod,

I miss-spoke when I said PCM, I meant CCRM. I know which is which, and I have been following the other post. I got your diagrams and using a DMM I'm checking all the leads to the CCRM.

I would still like to see the diagrams for the PCM, though, if that is possible.

Thanks,
Russ

ps I started this thread to see if you thought that my symptoms point to something different than the other thread. He's got a 93 Sable and I have a 92 Taurus. Sorry for any confusion.

[shorod]

Originally Posted by elvisload

Rod,

I miss-spoke when I said PCM, I meant CCRM. I know which is which, and I have been following the other post. I got your diagrams and using a DMM I'm checking all the leads to the CCRM.

I would still like to see the diagrams for the PCM, though, if that is possible.

Thanks,
Russ

ps I started this thread to see if you thought that my symptoms point to something different than the other thread. He's got a 93 Sable and I have a 92 Taurus. Sorry for any confusion.

I'll try to get that diagram for the PCM pinout up tonight. Otherwise it will probably be Thursday evening. I would imagine the CCRM would be the same between your 92 and his 93. Sable versus Taurus shouldn't make difference on the CCRM. Compare the wiring colors of the CCRM to be safe. The diagrams I have are for a '93, I don't have diagrams specific to a 92, but since there wasn't a large model change between 92 and 93, I think it will be the same. I would suggest running the checks outlined in the other post. I'm not aware that it is common for the ground wire to go bad, so I don't know that your problem will be as inexpensive. I have seen the CCRM modules go out, and I don't think they are cheap.

[edit] I got the PCM pinout and connector view up. See them at http://www.members.aol.com/Rod241473...PCM_pinout.jpg and http://www.members.aol.com/Rod2414738/Car_Stuff/PCM.jpg

Good luck!

-Rod

[elvisload]

Rod,

Got a DMM and started the tests today on the CCRM. Results as follows:

All tests done by back probing with CCRM connected.

pin 24 - red lead with black lead on pin 15 - run and start key position 12 Volts

pin 24 - red lead with black lead on battery neg - run and start key position 12 Volts

pin 12 - red lead with black lead on pin 15 - run and start key position 12 Volts

pin 18 - black lead with red lead on battery positive - run position 12 Volts - start position Zero Volts!! (did this one several times)

pin 5 - red lead with black on battery negative - failed test - zero Volts at run and start position

The measured resistance from pin 15 to battery negative was just a few tenths of an ohm.

Battery tested at just above 12 Volts.

(All the above readings on start position were actually just slightly lower than 12 Volts, except pins 18 and 5, which were 0 Volts)

Whadaya think? BAD CCRM? SOMETHING ELSE?

[elvisload]

Also Rod,
Thanks for the PCM diagrams. Sure I'll need them at some point. As John said, "you the man!".

[elvisload]

ADDITIONAL INFO:

Just noticed that the "check engine" light does not come on in the run or start position. Does this indicate anything?

[shorod]

Originally Posted by elvisload

Rod,

Got a DMM and started the tests today on the CCRM. Results as follows:

All tests done by back probing with CCRM connected.

[snip]
pin 18 - black lead with red lead on battery positive - run position 12 Volts - start position Zero Volts!! (did this one several times)

pin 5 - red lead with black on battery negative - failed test - zero Volts at run and start position

[snip]
Whadaya think? BAD CCRM? SOMETHING ELSE?

Well, the more I think about it, the more this is probably correct. When you turn the key to the run position, the pump runs to pressurize the fuel system. When you crank the engine (start position) there is probably enough pressure in the system to normally get the car started. If the pump was running continuously here there is a chance the engine might flood. Of course, if the fuel pressure regulator is working and the injectors don't leak that shouldn't be a problem. You might want to see if jmoritz to see if he'll make a comparison reading for you now that he has his car running.

In any case, the fact that you get battery voltage with the key in the run position, the relay and CCRM module is doing its job. If what you are seeing is not correct, the problem is not with the CCRM but rather with what drives the CCRM fuel pump circuit (PCM?). However, it is getting the correct signal when in the "run" position, so the driver in the PCM must be healthy.

Try your readings at the inertia switch and/or fuel pump again with the key in the run position. If you have battery voltage at the CCRM pin 5 in "Run" but not at the inertia switch, then your problem is somewhere between them. Make certain that you have a good ground on the DMM when making this measurement. If you now have voltage at the switch, then check at the wiring to the fuel pump (I know, that is easier typed than performed). Use the same power and ground that the fuel pump uses (I'll try to get that diagram posted too). Also, at one time there was a TSB regarding fuel pump noise over the radio on many Fords. The solution was to install a filter inline with the power to the fuel pump. If sometime someone performed this filter installation, they cut wires to install the filter and maybe didn't solder the wires well or didn't properly insulate the splices. Maybe the wires are corroded and open at the splices (if the filter install was done).

Fuel pump connector diagram can be found at http://www.members.aol.com/Rod241473.../fuel_pump.jpg

-Rod

[elvisload]

Originally Posted by shorod

Try your readings at the inertia switch and/or fuel pump again with the key in the run position. If you have battery voltage at the CCRM pin 5 in "Run" but not at the inertia switch, then your problem is somewhere between them.
-Rod

I don't have battery voltage at pin 5 run or start position.

pin 5 - red lead with black on battery negative - failed test - zero Volts at run and start position

and,

pin 18 - black lead with red lead on battery positive - run position 12 Volts - start position Zero Volts!!


so,

I'll look for Voltage back at the inertia safety switch in both positions again but I doubt that it's there.

I did find two wires on the CCRM harness (very near the CCRM) that had been cut and then reconnected with wire connectors. They are at Pin 14 (orange) and Pin 18 (blue and orange). I'll pull those apart and reconnect them with solder.

Russ

[shorod]

Originally Posted by elvisload

I don't have battery voltage at pin 5 run or start position.

pin 5 - red lead with black on battery negative - failed test - zero Volts at run and start position

and,

pin 18 - black lead with red lead on battery positive - run position 12 Volts - start position Zero Volts!!




so,

I'll look for Voltage back at the inertia safety switch in both positions again but I doubt that it's there.

I did find two wires on the CCRM harness (very near the CCRM) that had been cut and then reconnected with wire connectors. They are at Pin 14 (orange) and Pin 18 (blue and orange). I'll pull those apart and reconnect them with solder.

Russ

Sorry, I guess I didn't pay close enough attention to your post. You're right, you probably won't see voltage at the safety switch if you don't see it on pin 5 of the CCRM. I wouldn't expect pin 14 to cause a no-start problem, it controls the low speed engine cooling fan. Pin 18 seems to be okay since you get voltage on it in the run position, but I don't trust crimp connectors, especially under the hood. If if isn't bad yet, it's only a matter of time.

Since you have battery voltage to both pins 12 and 18 in run, but not on pin 5, then I'd say there is a good chance your problem is the CCRM.

-Rod

[elvisload]

-UPDATE-

Soldered the wire connections at pin 14 and pin 18, near the CCRM, where the wires had been cut at one time.

Swapped out the CCRM with two different ones from a salvage yard (same numbers)

Still no start and I never hear the fuel pump run at all (run or start key position). In fact the only time I’ve heard the fuel pump run at all, is when I had it out of the tank, on the bench, and connected to battery voltage.

And on another front. The idiots at Pep Boys (before I got the car) let the PCM test plug (the plug is labeled 'EEC TEST') dangle down onto the manifold (or some other extremely hot spot on the engine back by the firewall) and the plug melted beyond repair. I’ve cut the plug off and made sure the remaining wires aren’t touching. The plug is located on the passenger side under the hood near the firewall.

Going to find another test plug end from the salvage yard and attempt to splice it back into place. Being careful to match up wire colors and soldering connections.

Is there a wiring diagram available for the 'EEC TEST' plug?



Any thoughts?

[shorod]

Originally Posted by elvisload

-UPDATE-
[snip]

Swapped out the CCRM with two different ones from a salvage yard (same numbers)

Still no start and I never hear the fuel pump run at all (run or start key position). In fact the only time I’ve heard the fuel pump run at all, is when I had it out of the tank, on the bench, and connected to battery voltage.
[snip]

Is there a wiring diagram available for the 'EEC TEST' plug?

With the key in the run position, turn on the air conditioner and see if the cooling fan on the radiator runs. If not, it would seem to me that you are not getting enough power (or ground) to the CCRM for the relays to properly operate. If you have good voltage on pin 24, the same relay that provides power on that pin also provides power to the remaining relay coils in the CCRM, so if the relay for the fuel pump is getting a good ground signal and pin 12 has good battery voltage, then the fuel pump relay should be closing and providing power to the fuel pump circuit. Have someone turn the key on and off while you listen to and hold a finger on the CCRM, paying attention for relay closres. Of course you will want to have the A/C turned off at this time as well as the blower motor and radio so that you can hear any relays better. You should at least hear/feel the relay that provides power to the PCM. You probably won't be able to tell if other relays are operating or not.

Do you happen to have a current meter that you could install on the wire to pins 12 and 18? Do you have a test light? You wouldn't happen to be near Cedar Rapids, Iowa, would you? I'm not sure how much more help I can offer without actually performing some checks in person. Do you have a fuel pressure gauge?

What are you looking for in the EEC Test diagram, wiring colors or electrical function?

-Rod

[elvisload]

Rod,

Guess what? Got it running! It was that friggin EEC TEST plug. Went to salvage found one off a 92 Sable, checked to see that the wire colors matched. Spliced and soldered all 10 wires! Turned the key....VROOOM!

Apperantly the PCM or CCRM will not function without the EEC TEST plug in place. Eight of the 10 wires are in like pairs (same colors) so I'm assuming those are meant to be connected through the plug. With the plug cut off...no connection!

Rod said:
"What are you looking for in the EEC Test diagram, wiring colors or electrical function?"

Russ says:
I'd love to have both diagrams if they are available.

And Rod, I couldn't of done it without your help. I know it's extremely difficult to diagnosis without seeing the car... you probably would have made the right call within minutes of seeing the engine. But your posts here and with John's Sable led me in the right directions. Thanks a million!

Russ

[shorod]

Originally Posted by elvisload

Rod,

Guess what? Got it running! It was that friggin EEC TEST plug. Went to salvage found one off a 92 Sable, checked to see that the wire colors matched. Spliced and soldered all 10 wires! Turned the key....VROOOM!

Apperantly the PCM or CCRM will not function without the EEC TEST plug in place. Eight of the 10 wires are in like pairs (same colors) so I'm assuming those are meant to be connected through the plug. With the plug cut off...no connection!

Rod said:
"What are you looking for in the EEC Test diagram, wiring colors or electrical function?"

Russ says:
I'd love to have both diagrams if they are available.

And Rod, I couldn't of done it without your help. I know it's extremely difficult to diagnosis without seeing the car... you probably would have made the right call within minutes of seeing the engine. But your posts here and with John's Sable led me in the right directions. Thanks a million!

Russ

That's great to hear! I'm not sure I would have suspected the EEC Test plug to cause your problem, but I'm not sure we're thinking of the same plug when we talk EEC Test plug. My recall of the EEC Test plug is the diagnostic connector for checking codes on a Ford. The plug is a 6-socket connector with only 5 of the sockets used. I don't recall multiple wires going to the terminals. See the diagram on the upper left at http://www.members.aol.com/Rod241473...uff/system.jpg

A close up, although out of proportion, view of the connector and wire colors can be found at http://www.members.aol.com/Rod241473...Stuff/plug.jpg

Great job on getting your car running again!

-Rod