SOLVED: Help with CEL P2716 - Powertrain - Pressure Control Solenoid D Electrical (1 Viewer)

[xXsnowXx]

Disclosure. I've searched for this specific fault code, and there are a few results, but it seems like they also had other codes and their situations were a bit different. So I'm posting here hoping to get some guidance.

I think it is first worth mentioning an issue I had recently that may or may not be related to this new fault.

A while back I noticed that my USB Car Charger stopped working (plugs into cigarette lighter). I had been using it for a few years so I just thought it went bad. But I realized that all my 12v outlets weren't working. All three. So I checked the fuses and they were indeed blown. I replaced them, and dumb me decided to check to see if the outlets were fixed by trying the USB Car Charger again. And, you guessed it, it blew all three fuses again. So something was up with the USB Car Charger. I threw it away and replaced the fuses again. Now here is where I really messed up. When I was changing out the fuses, I was just looking at some of the other fuses. I ended up accidentally putting one back in the wrong place. If I remember right, I put the ETCS fuse back into an unused slot right next to it. I didn't notice until I started the truck and moved it out of my garage. Noticed the CEL and it running rough. I immediately shut it off and figured out what I did and fixed it. After that (I assume related to this mistake) I got a CEL for a bad O2 sensor. I replaced it and everything seemed fine for a while. All of that could be unrelated to my current issue, but the timing seems like they could be related.

About a month later, I had the CEL come on. I scanned it and it is P2716 - Powertrain - Pressure Control Solenoid D Electrical. At first, I could turn off the truck and turn it back on and it would run fine (I'd clear the CEL and it wouldn't come back on). Because of this, I just thought maybe I drove through a puddle and something got wet (seems to be one cause that I've read). Then it came on again a few hundred miles later. Same thing, cleared it and it stayed off for a while. Then it was more consistent and wouldn't go off. So it seems that there is something wrong. Hopefully that is useful information for diagnosing, happening rarely and then more and more until constant.

So now I'm doing what I can to figure out what the problem is. The FSM says:

A more generic site says the following:

Causes

• Insufficient transmission fluid
• Dirty transmission fluid / filter
• Frayed wiring / damaged connectors
• Failing pressure control solenoid
• Failing transmission pump
• Internal pressure problems
• Valve body issue
• ECU or TCM failure

So the things I've tried so far, trying to do the easiest things first:

• I checked all the electronic connections around the transmission that I could find, looking for damage, looseness, etc. They seemed fine.
• I checked the transmission fluid level. Being a 2004, there is not a dipstick. I got the truck up to about 100*F, idling, leveled (a level on the transmission pan, is that okay?), and the check valve released about a quart of ATF before it came to a drip. So I assume if anything, it had too much fluid. The fluid was pretty dark. Had a little pink/red color to it, but not a lot. Truck has 180k and I assume the original ATF.

Unless someone else has some suggestions, my next steps will be to drop the pan and do a few things: replace or clean filter, clean pan, inspect the SLT solenoid connection while I'm in there, new fluid, etc. I am no mechanic, and this will be very new territory for me, so I'm open to suggestions.

Thanks!

 

[hewitttech]

Did you take apart the connectors and look at the pins in all of the transmission connectors? It is pretty common for water to get into the pins eat/corrode/short/melt between the pins. It is fairly common cause of solenoid circuit codes. If those all look good I would trace to the ECM next. Then drop the pan and inspect the internal wiring and ohm out the solenoid according tot he FSM specs.

 

[xXsnowXx]

Did you take apart the connectors and look at the pins in all of the transmission connectors? It is pretty common for water to get into the pins eat/corrode/short/melt between the pins. It is fairly common cause of solenoid circuit codes. If those all look good I would trace to the ECM next. Then drop the pan and inspect the internal wiring and ohm out the solenoid according tot he FSM specs.

I checked a few, the easiest to reach ones. They seemed okay, but I'm thinking I'll check them all with more thoroughness. How many total connectors are there (opening up the FSM now, so I might figure it out)?

When you say "trace to the ECM next", do you just mean make sure all the wires from the transmission leading to the ECM all look undamaged and connections to the ECM look good?

 

[hewitttech]

Its a 15 pin connector on the side that comes up out of the pan if I remember correctly. You will Ohm the wires out between the ECM and the trans. connnector to make sure there are no breaks or shorts between the ECM and the connector. Then you follow it into the transmission and the shift solenoid. You can Ohm out the solenoid from the connector before going in. That just tells you if the internal harness and solenoid is OK. You have to go into the trans to determine if it is the internal harness or the solenoid itself. About 75% of the time it is just the connector and the rest a mix of the solenoid or harness.

 

[BnvS]

@hewitttech kinda like the transmission connector issue that happens on the 4runners? is that what you mean? i.e. when the connector gets corroded and stops making the connection which then throws codes?

 

[hewitttech]

@hewitttech kinda like the transmission connector issue that happens on the 4runners? is that what you mean? i.e. when the connector gets corroded and stops making the connection which then throws codes?

Yes, I have seen it happen on all of the models particularly the Tundra (just way more of those around so its more common).

 

[xXsnowXx]

This is all super helpful and very appreciated. I was worried I wouldn't get any responses and I'd be winging it. I feel much more confident now.

 

[xXsnowXx]

Its a 15 pin connector on the side that comes up out of the pan if I remember correctly. You will Ohm the wires out between the ECM and the trans. connnector to make sure there are no breaks or shorts between the ECM and the connector. Then you follow it into the transmission and the shift solenoid. You can Ohm out the solenoid from the connector before going in. That just tells you if the internal harness and solenoid is OK. You have to go into the trans to determine if it is the internal harness or the solenoid itself. About 75% of the time it is just the connector and the rest a mix of the solenoid or harness.

I thought I was going to figure it out without needing to ask, but can you tell me what the best process is for "ohm the wires out" in this particular situation? I have very little experience with automotive electrical stuff but am willing to learn. I think the only thing I'll need is a multimeter, right?

 

[hewitttech]

Yes, you will need a good quality digital multi-meter/Ohm meter and an electrical diagram for connector, pin and wire identification.
It is fairly straight forward usually. Basically you start by disconnecting the harness from both ends, the ECM and the transmission.
Then one wire at a time (on the involved circuit wires) you measure the resistance of each from one end to the other. Most often the resistance you are looking for is less than 1 Ohm. You then measure the resistance at one end of each wire to ground and to the the other wires making sure there are no shorts between them This is usually specified as greater than 10k Ohms. The factory service manual for your codes will give you what you are looking for circuit/wire and resistance specs and there are probably some pretty decent YouTube videos that can explain the harness diagnostic techniques and how to use your Ohm meter.

 

[xXsnowXx]

Yes, you will need a good quality digital multi-meter/Ohm meter and an electrical diagram for connector, pin and wire identification.
It is fairly straight forward usually. Basically you start by disconnecting the harness from both ends, the ECM and the transmission.
Then one wire at a time (on the involved circuit wires) you measure the resistance of each from one end to the other. Most often the resistance you are looking for is less than 1 Ohm. You then measure the resistance at one end of each wire to ground and to the the other wires making sure there are no shorts between them This is usually specified as greater than 10k Ohms. The factory service manual for your codes will give you what you are looking for circuit/wire and resistance specs and there are probably some pretty decent YouTube videos that can explain the harness diagnostic techniques and how to use your Ohm meter.

Thank you, very helpful. I have found a few other resources out there that should also be helpful.

 

[xXsnowXx]

Just an update in case anyone else has this error code in the future. Today I planned on doing a handful of things to track down the problem. Luckily for me one of the first things I checked ended up being the problem (or at least part of the problem). The first thing I checked was the transmission wire harness. The connection that leads away from the transmission (male end) appeared decent, but was a little dirty so I cleaned it the best I could. The female end, that leads into the transmission, had some obvious damage to one or more of the pins. See photo. The bottom row of pins looks pretty rough and the third from the left was completely gone. This seems to be exactly what hewitttech said in his first reply above, "Did you take apart the connectors and look at the pins in all of the transmission connectors? It is pretty common for water to get into the pins eat/corrode/short/melt between the pins."

Anyway, I had luckily already ordered a replacement transmission wire (82125-35130, $40), so I went ahead and started the process to replace it. I drained as much ATF as I could. I then dropped the pan. I disconnected all the transmission wire connectors and removed the bad transmission wire. And then reverse to install the new transmission wire. So far this has fixed my issue. No more CEL.

A few notes:

• I drained almost exactly 8 quarts of ATF. Probably 3 from draining, 3 more when I dropped the pan, and then the rest from the two ATF temperature sensors holes when they were removed (they are part of the transmission wire, see page AT-6 in the FSM). That last part surprised me a bit, when ATF continued draining out of those holes for several minutes, though at a slow pace. I put 8 quarts of new ATF in when I was done. When I checked the level (using the overflow plug), maybe 1/2 quart came out).
• I didn't have too much trouble dropping the pan. A few bolts are difficult to get to, but luckily I had a pretty good variety of ratchets, sockets, and extensions; despite not being a mechanic at all. I was pleasantly surprised with the cleanliness of the pan, magnets, and the condition of the gasket. I don't know how well those gaskets hold up, but it makes me think it was not the original. The ATF that I drained was dark, but still had a red tint to it.
• The most difficult part of the entire process for me was removing the old transmission wire. Specifically where the harness transfers from inside the transmission to the outside. I wasn't sure if there was some trick to removing it, but it wouldn't budge. In hindsight, lubing it up (there is an o-ring in the middle) probably would have done it. I ended up breaking the plastic part and then it came free. The new one went in smooth 75% of the way, which was enough to get the bolt started and tightening it pulled the harness the rest of the way in.
• My overflow plug (5mm hex) is stripping out. I had to use a similar size imperial to get it out. I'm going to order a new one. I think it'll be okay until I can replace it.
• I used an oil pump from Harbor Freight to refill the ATF. It worked well. If it didn't, I was going to do the "lazy mans" technique.

Hope this helps anyone who may have this issue in the future.

 

[BnvS]

Great follow up. Good to know you found the problem.

 

[abuck99]

Good job!

The harness looks like fun - 8 internal connectors to contend with.

Good thread notes. If you are able to take a sharper pic of the connector please post. I don’t often notice factory connectors with grease in them - wonder if someone had been in there before with same problem and greased that connector.

 

[BnvS]

ooh @xXsnowXx Did you put dielectric grease on the connector? I would suggest you put that on the external female connector that got corroded. Dielectric grease keeps this from happening. I.e. stops moisture from getting into the connector and rotting them out.

Here's how you need to use it. How to use dielectric grease.

@abuck99 perhaps the grease you are seeing is dielectric grease?

 

[xXsnowXx]

ooh @xXsnowXx Did you put dielectric grease on the connector? I would suggest you put that on the external female connector that got corroded. Dielectric grease keeps this from happening. I.e. stops moisture from getting into the connector and rotting them out.

Here's how you need to use it. How to use dielectric grease.

@abuck99 perhaps the grease you are seeing is dielectric grease?

I didn't, but I will definitely consider getting back under there to add it. Thanks for the video link, I probably would have used too much or applied it incorrectly without it.