Electrical testing of Transmission Solenoid PLEASE HELP

[pet575]

I'm attempting to test my solenoid pack in my 5R55S transmission. Trouble is I'm a newbie when it comes to using a multimeter and testing resistance. The repair manual I have says the resistance on the TCC Solenoid should check in between 9-16 Ohms.

The results I'm getting with my multimeter set to Rx1k is zero. No matter which pins I check I get a zero reading. When i switch the multimeter to Rx100 I get the same and when i switch it to Rx10 I get something like a 0.20 reading.

I followed the multimeter instructions to zero out the meter when touching the leads of the multimeter together.

What am I doing wrong? Why do I keep getting zero readings no matter what I do?

Please help! Thanks!

 

[imp]

First, you need to understand how an Ohmmeter works. Then, you need to understand how to interpret the results.

An Ohmmeter places a small voltage across the two points to which it is connected. A very small amount of current flows out of the ohmmeter and through the device being tested, and returns to the meter. The AMOUNT of current which flows determines the meter reading. A HIGH resistance allows only small current flow, and vice versa. That is why several different "ranges" are provided on the meter.

In the case of an expected resistance value of about 10 ohms or so, the usual "scale" used would be "R X 1", in which each incremental number on the scale represents 1 ohm of measured resistance.

Now, you MUST connect the ohmmeter leads to the CORRECT pair of connections to provide useful information. You MUST know in advance, which two connections are the ones which lead to the solenoid coil in question. The work MUST be done with the connector at the transmission or computer disconnected, to isolate the solenoid(s) from other circuitry which runs it's operation. Wiring diagrams provide info about which wire feeds what. Failing in that, the solenoid(s) may be removed from the transmission, which they may ALREADY have been, anyway, and then tested on the workbench.

But, the 5R55S has a MODULE which contains all 8 solenoids mounted to a common "carrier", which is fastened to the valve body within the transmission. Thus, having them on the bench, one must know which one is which, when testing them. Quite frankly, if this is the scenario, after the work involved in removing them, if it is STRONGLY suspected that one of them is haywire, it's not a bad idea to simply buy a new module for a couple hundred bucks, and throw it back in. If you guessed wrong, and solenoid trouble was nonexistent, you have at least updated and bypassed possible near-future problems.

In the case where solenoid trouble is indicated by trouble-codes, while these are not infallible, they are very often quite accurate. If a code indicates a certain solenoid is electrically malfunctioning, it's pretty certain that's true. Thus, in the 5R55S, since solenoids are not individually serviceable, such info leads usually to a module replacement, all 8 are included. The Torque Converter Clutch Solenoid is often a culprit, as it was in my 2004. That baby switches on and off every time the driver releases the gas pedal! imp

 

[JoshMcMadMac]

To add on, there is no guarantee that the solenoid is good if it passes the electrical test. It can be an intermittent issue, an issue only when hot, or a physical defect in the solenoid that is non-electrical. If your issues are symptomatic of a failing solenoid block, you are almost certainly best off spending the $300 on a new replacement and moving on.

 

[pet575]

Thanks for the responses guys. This testing is in relation to the issue I'm having with the TCC failing to lock as discussed in this thread:

http://www.explorerforum.com/forums/showthread.php?t=390876

I had no symptoms of a solenoid issue outside of the TCC failing to lock and the trouble code referred to in that thread.

I'm in the process of putting everything back together and I was doing the testing on the solenoid (with it out and on my test bench) to check it before putting it back in. My confusion here arises from the fact that EVERY test I do results in a zero Ohm reading on my multimeter. This is not a digital multimeter; it is the kind with the needle. This is not a case of the multimeter failing to give me a reading. When the leads aren't connected to anything, the needle is buried on the "high side" so that it reads over 1,000 ohms. When you connect it to something, the needle moves all the way to the opposite side of the range to zero.

I tell you that because I think I've eliminated the multimeter as the cause to where I'm getting no reading whatsoever. My confusion comes because I've got the manual referred to in the other thread and I'm specifically touching the leads to the appropriate pins on the solenoid block to test for all things (Shift solenoid A, B, C, etc. and TCC) and no matter which test I correctly perform (again, I think) I am getting a zero reading.

I don't understand this result and that is what led me to think my relative inexperience with the multimeter was causing it. However, after reading the much-appreciated detail that IMP gave above, I don't think I'm doing anything wrong. My confusion is centered around why EVERY test would result in zero ohm readings when this solenoid wasn't giving me symptoms with EVERY shift (only the TCC lock issue).

I guess the short question is, "How can the entire solenoid be 'bad' now when it didn't show those symptoms prior to removal?"

 

[Sixonemale]

To add on, there is no guarantee that the solenoid is good if it passes the electrical test. It can be an intermittent issue, an issue only when hot, or a physical defect in the solenoid that is non-electrical. If your issues are symptomatic of a failing solenoid block, you are almost certainly best off spending the $300 on a new replacement and moving on.

Completely agree. About a year ago I had my 2002 Explorer transmission rebuilt and had the choice between a brand new or rebuilt solenoid and chose the later. After about nine months it began to throw codes, but I did not think it was solenoid. It was also tested by two transmission experts with a computer that said the solenoid was operating fine. I then had the solenoid pack changed out because that was what the codes were referring to for another rebuilt solenoid pack, and guess what codes were thrown again. It was also checked out by transmission experts who said it was operating fine. It took a lot of unnecessary time to troubleshoot other items that I should not have been looking at. I finally had a new OEM solenoid pack put in and guess what, no codes and works great. I think more times than not it's an intermittent issue within the solenoid pack and the only way to solve this problem is to replace it with a brand new solenoid pack.

 

[JoshMcMadMac]

I had no symptoms of a solenoid issue outside of the TCC failing to lock and the trouble code referred to in that thread.

Makes sense; the torque converter can definitely fail all by itself.

I guess the short question is, "How can the entire solenoid be 'bad' now when it didn't show those symptoms prior to removal?"

It most likely is not bad by your current diagnosis. It is either an incorrect pinout you are referencing or the meter. Analog multimeters are sensitive, and relatively easy to damage. If possible, get a cheap digital meter to test with and see if you have better luck.

Completely agree. About a year ago I had my 2002 Explorer transmission rebuilt and had the choice between a brand new or rebuilt solenoid and chose the later. After about nine months it began to throw codes, but I did not think it was solenoid. It was also tested by two transmission experts with a computer that said the solenoid was operating fine. I then had the solenoid pack changed out because that was what the codes were referring to for another rebuilt solenoid pack, and guess what codes were thrown again. It was also checked out by transmission experts who said it was operating fine. It took a lot of unnecessary time to troubleshoot other items that I should not have been looking at. I finally had a new OEM solenoid pack put in and guess what, no codes and works great. I think more times than not it's an intermittent issue within the solenoid pack and the only way to solve this problem is to replace it with a brand new solenoid pack.

Unfortunately this is a common scenario. No one likes to hear they should spend $300 when $100 will do, and that is compounded when shops are made out to look like the bad guy when they make such a suggestion. That is the primary reason there are members here that "broken record" about buying a new, current version solenoid block straight from a dealer. These solenoid blocks cannot be truly rebuild or re-manufactured. Even if they were, they are not up to the latest revision from Ford which is 9L2Z-7G391-A.

 

[pet575]

I guess I'll be testing this with a different multimeter to see what I find. It makes zero sense to me that I'd get these results. I'm having a hard time understanding how the solenoid pack would go bad simply by sitting in my garage after removal. Hopefully the test with a different multimeter clears this up.

I'll let you guys know what I find out. Hopefully soon.

Thanks for the responses so far!

 

[imp]

I guess I'll be testing this with a different multimeter to see what I find. It makes zero sense to me that I'd get these results. I'm having a hard time understanding how the solenoid pack would go bad simply by sitting in my garage after removal. Hopefully the test with a different multimeter clears this up.

I'll let you guys know what I find out. Hopefully soon.

Thanks for the responses so far!

TCC solenoid coil acceptable resistance, measured at the harness connected to the solenoid module, is 9 to 16 ohms. The other solenoids, 16 to 45 ohms. "Needle" type meters (analog meters, like Simpson 260) have SEVERAL resistance RANGES. If you are using a 1000 ohm range, the reading of 4 to 6 ohms would not be discernible as other than ZERO on the meter's scale. Low resistances such as these must be viewed with the meter set at "R X 1" ohms, that is, each DIGIT on the scale represents 1 ohm. (1, 2, 3, etc). imp

 

[pet575]

TCC solenoid coil acceptable resistance, measured at the harness connected to the solenoid module, is 9 to 16 ohms. The other solenoids, 16 to 45 ohms. "Needle" type meters (analog meters, like Simpson 260) have SEVERAL resistance RANGES. If you are using a 1000 ohm range, the reading of 4 to 6 ohms would not be discernible as other than ZERO on the meter's scale. Low resistances such as these must be viewed with the meter set at "R X 1" ohms, that is, each DIGIT on the scale represents 1 ohm. (1, 2, 3, etc). imp

Starting to think this is where I'm going astray. I borrowed another multimeter last night and it was also the needle type. It did exactly the same thing but it did not have an RX1 setting. Mine only goes as low as RX10. Maybe I need to replace my multimeter with the digital readout type in the future.

Until then, I'm just going to roll with this thing or talk myself into a digital readout multimeter. Either way, I'm less concerned than I was at first so I'm just going to progress with reassembly of the transmission to see if my other repair fixed my problem.

Thanks for all the info and replies!!!

 

[pet575]

Well I decided to stop being an idiot and replaced my analog multimeter with a digital one. Presto! I got my readings I was looking for. TCC test checked out at 13-14, which was right in the 9-16 ohm resistance range. So for purposes of this discussion the answer was, like always, to have the correct tools to make life easier.

Thanks again to all for helping me avoid any further self-mutilation and unnecessary complication.

 

[jojotheclown]

Amazing this came up the same time I'm looking for a pin out chart at the PCM.

Does any one have one, trying to do some minimal testing before I go under the truck.

I have a 2003 Flex Fuel V6 with a V code trans.
I had a code P0775

 

[imp]

Well I decided to stop being an idiot and replaced my analog multimeter with a digital one. Presto! I got my readings I was looking for. TCC test checked out at 13-14, which was right in the 9-16 ohm resistance range. So for purposes of this discussion the answer was, like always, to have the correct tools to make life easier.

Thanks again to all for helping me avoid any further self-mutilation and unnecessary complication.

Please keep in mind that a good resistance check on a solenoid coil does not necessarily mean the solenoid is functioning properly! Mechanically, the plunger which moves within the coil when it's activated may be sticking or jammed, preventing the proper directional control of hydraulic fluid. The guide bushings for the plungers in these are known to occasionally crumble (they're made of bronze in Bosch-built modules), which prevents the solenoid from operating properly. It happened to me on my '04. Bits of bronze atop the valve body.

This is why testing solenoids by applying voltage to them, and listening for the tell-tale "click" as the plunger is thrust back and forth, is a reasonable way of mechanically checking function, as someone mentioned above. imp

 

[imp]

Amazing this came up the same time I'm looking for a pin out chart at the PCM.

Does any one have one, trying to do some minimal testing before I go under the truck.

I have a 2003 Flex Fuel V6 with a V code trans.
I had a code P0775

I'll scan that pinout, and post it if you can wait until tomorrow. PM me if I forget. imp

 

[imp]

5r55s/w pcm pinouts

Here they are.

I hope this proves helpful to you. In the future, I would recommend ordering a Ford Shop Manual, as few will stoop to spending the time to do this. Best regards.....imp

 

[imp]

Ads!

My post above has ads blocking some of the content. Big Rondo advised me of ways around that. If you still need the complete pinout, let me know, I'll PM it to you. imp

 

[Jlterrones]

Hey imp im looking at the connector layouts. What year is that for?

 

[imp]

ones

Hey imp im looking at the connector layouts. What year is that for?

@Jlterrones
2004. imp

 

[adolfomantis]

ones
@Jlterrones
2004. imp

Hi guy. I drove me crazy myself yesterday making tests with your pics. I think they has a mistake.

UPPER connector in PCM under hood (In my XLT 4.0 2004 explorer) is C175t (connector from PCM to transmision) and is NOT meddium connector.

Medium connector is C175b (body) an lower connector is C175e (engine)

I checked all solenoids thru C175t (UPPER) connector and fuse terminal (F1.37)
(without fuse) and all solenoids have correct resistence range, so i think i have to get down solenoid block to check mechanical failure (debris or dirty). Problem occours at "Drive" when transmission tries to change from 1st to 2nd gear (doesn´t change), some time after this, O/D light blinks. OBD Code is P0732 (Incorrect 2nd gear ratio).

 

[Jlterrones]

Yup same with mine. So i just fixed my problem yesterday. So i had a code p0970 (pressure control solenoid c low resistance) so i took off the solenoid pack and replaced solenoid c which i had from a solenoid pack i replaced last year but still giving me the same code. So last week i tested the transmission to pcm harness and its got current so its good. I checked all fuses and relays and they were also good. So my conclusion i either had a bad pcm or a bad solenoid pack which i ddnt think because it was only a year old and i had replaced solenoid c. So yesterday i go under the transmission and take off the solenoid pack to test it. I test the solenoid it was fine but so i tested all the solenoids to connector and c wasnt working so so i found the broken piece and replaced it with one of the old ones which i recommend u replace the solenoid pack because its very delicate and you would actually need to have an extra solenoid pack for the part but i put it back together and it works great. This is a pic of the part that was broken. Its from the otherone i have extra. Its missing parts bcause i been playin with it for a while now

 

[imp]

@adolfomantis
Yes, I found the official Ford Wiring Diagrams have a mistake. The 3 PCM connectors are not labeled correctly. I spent a very long time tracing wires and measuring continuities. I think I have sorted it out. Tomorrow, I will go back to the diagrams. Sorry for any trouble I caused you. I experienced the same things: the actual wiring simply did not match up with the diagrams. Much trouble. imp