So I recently posted several issues including a code 624 and a hard 1st to 2nd gear shift. The other issues went away but the transmission issue stuck around. I broke down and brought it to the local shop. They used to specialize in transmissions butknow do that and more. $1200 later I pick up a truck with a bad 1st to 2nd gear shift and a code 624.

They checked the MLPS and the wiring. They replaced the solenoid pack because it was leaking into the connector. I knew that leak existed but didn't know if that was causing the problem. Obviously it was not the problem because they told me the problem was still there. The shop then replaced the accumulator, and related springs, a valve, because it was supposedly stuck, and some other stuff. I picked it up late Friday and immediately noticed it was still shifting hard.

So to today I went to check for the code 624 and found it still there. I then went to erase the codes so I could take it for a test drive and see if the code comes back. I CAN NOT GET THAT CODE TO GO AWAY! I have disconnected the reader while the codes were transmitting, I have disconnected the battery, and I have tried turning the key off while the codes were transmitting. The code is still there.

So, anybody had this happen before?
How do I get that code cleared?
Anything I can look for regarding the code 624 that they may not have thought of ?

 

624 (O,M) Solenoid/circuit failure -Electronic Pressure Control (EPC) current is high

well,they should of tested the solenoid.since it was leaking anyway though,that should be replaced and the odds were good it should of fixed it too.
how about the solenoid pack plug though? did you inspect that meticulously? you can replace it too.they are early/late years specific.be sure to get the correct year,but google;
E4OD repair harness

you can (and should) find the pin location for the EPC at the PCM connector and the EPC pin at the solenoid connector and read resistance (using ohms on your multi meter) to first see if the line is in fact open.if so,the odds are,it will be near the pack plug.
there is a plug up by the inner fender (92-96) that you should also inspect.i dunno if the EPC line runs through that or not,but cleaning it wont hurt anyway.follow the trans harness up the drivers side,up over the frame and reach up and look.you'll see it splitting off with some wires going to this small square plug/connector then into the power distribution box and the majority going over to your pcm connector.

it is odd the code wont clear.i wonder if the only way it will clear though,is when it no longer senses an open/broken line and needs the return signal from the EPCS.........probably so.

$1200 for a solenoid pack replacement and some failed diagnoses.ouch! that's not being treated fairly according to anyone's book.don't go back there again.

 

The code won't clear because the problem is still there. Since you've changed everything else the problem MUST be in the wiring harness. Either find and fix it, or replace the wires from the PCM to the transmission connector for the EPC solenoid.

 

So I found the problem myself kind of by accident. The responses to the thread were on the right track regarding wiring.

I left the battery disconnected for a day, hooked it back up and went to read the codes. Sure enough 624 was still there. I was doing this at night with a flashlight suspended between the brake booster and the fuse box. Well you know how sometimes you can see more at night with a flashlight than during the day with sunlight? This was one of those times. I happen to look down and there I saw a broken wire at the back of a connector. I climbed underneath and followed the harness back to the transmission. I then pulled out my factory manuals and matched the connector to C110. This is a round connector with four wires not the bigger square one (C103). I then looked at the wiring diagram to find it was the wire that goes to the Electronic Pressure Control Solenoid.

Monday morning I went back to the shop with a picture of the broken wire, the wiring diagram, and the diagram that shows connector locations. I don't think the guy at the counter was very happy to see me. Eventually, I got a call from a very embarrassed mechanic that actually apologized and admitted he should have found the broken wire. But, he also tried to legitimize the work that he had done. So far there has not been an offer of a refund but the mechanic did suggest that they would try to make it up to me if we do any future work. I'm not sure how I am going to handle that part yet. I wanted to drive it and make sure it was fixed before I start discussing compensation. I have since driven it and it shifts smoothly now.

I'm guessing the code was clearing but the minute I did the new KOEO test the computer could not not find the connection to the solenoid so it set the code. Seems like a no-brainer now. If I would have had the time in the first place I could have figured this out. In the end I kind of had to make the time anyway.

Thanks for the help. I'll try to attach a pic of the broken wire in case in the future someone else has a similar issue.

 

yeah that's a real shame.they did have cause to replace the solenoid pack at least though,since it was leaking.to not first test the line using an ohm meter or simply first look for a broken wire like you did however and not resolve the issue right off the bat,there really is no excuse for their incompetence on that one.the right thing for them to do,would be to reimburse you for all their time spent not replacing the pack.
well that's good to know that circuit runs up through that small connector.i recently tried to open this one on chip truck a month or so ago to clean it but couldn't get it apart.i suspect it's corroded together in there lol! this encourages me to go ahead to soak it and get it cleaned up before it looses connection down the road.
thanks for posting back.good luck.