Most of the tuners have used pcm's vailable. Pcmforless does as well.

Be very careful concluding the pcm is toast. That is rarely the problem....but it might be in this case. Losing communications can be wiring issues as well as pcm issues...

 

I fully intend to have the pcm tested to make absolutely sure, but the wires are all ok, and. The pcm isn't commanding first after the first upshift. So that's pcm right? And it won't command 4th @ all. So I really think we can be pretty sure it's the pcm. Or is there something I'm missing

 

Tranny codes are not visible in the same place as engine codes on some scanners. And a tranny problem can do what you are experiencing.

I already told you my thoughts about the PCM being an issue. If you doubt it, why not borrow a stock unit from someone to try. There are so many from TX on this board, there has to be someone near you to try it.

 

That's what I'm going to try, don't get me wrong it's not that I don't believe what u r telling me, but with a scanner reading the car, we see that the pcm isn't commanding the car into 1st, it's throwing a 3-2 solenoid code, the statement about the ses light is referring to the pcm and engine codes.I can disconnect the maf and the ses comes in and the fans kick on, but it goes out with no logging what so ever of the code. Also the same thing if I disconnect my tps, doeant even show it as an intermittent code. Is that normal?

 

So thanks to verizon and blackberry I'm having a hard time logging on to the forum, I'm just gonna go get a droid, now back to the car. The car is developing some really interesting issues all of a sudden, this may or may not be a result of the issue @ hand. Now when I turn on my wipers the wipers funtion fine, until I turn off the wipers, they don't return to the off position. They stay up right on the windshield as if they were on delay, unless I fiddle with the switch, then it will return them to the off position. If I don't respond it's due to this great phone, so bear with me lol. But do u thing this can be related? And I know I shouldn't but just to see what happens I'm going to pull fuse 11 and see what happens. I was told if it's the pcm I should get a full upshift out of the car, including od. I don't see the logic but we'll see. Wish me luck. Ttyl

 

Well fuse 11 on I/P is only for the horn and lighter. Fuse 11 underhood is the ignition. So when you pull that, the engine won't run. And the Tranny has no power either. With the engine not running you won't get any shifting then.

Need to find someone else for advise.

 

I mean pull it and put it back in lol, the under hood fuse. But itd cold outsidE so I'm not doing anything today lol. I have it set up for it to go to chevrolet one more time on monday, so let's see what they don't figure out this time.

 

The circuit you are talking about has no power when the key is shut off. So pulling the fuse and putting it back in does NOTHING.

Look at it this way. Power comes from a switch through a wire through a fuse then onto the ignition circuits. When the switch is turned off, it is "open". Meaning for all intent and purpose, the wire is cut. It's the same as if the fuse were pulled out. And it happens every time you cut off the engine.
Get it. Nothing is going to happen.

 

So now that you have a code to work with, let's see what a DTC 84 would do to the vehicle. An 84 is the code for the 3-2 solenoid BTW.

According to the GM shop manual, A soft landing to 3rd gear and NO SES.

I believe you have been complaining that you only get 3rd gear yes or no?

This solenoid is powered up by fuse 11 U/H. However this fuse also powers the ignition system. So if the fuse or it's supply line were not providing power, the engine would NOT run since the ignition system would be DEAD.

The circuit in question is powered, as I said, by the #11 fuse U/H that is 10 amps. From there the power travels on a pink wire to the transmission connector into the 3-2 solenoid. Then back out through the same trans connector then out a white wire to the black PCM connector on pin 13.

So a DTC84 tells us that the PCM is not seeing 12 volts at pin 13 of the black PCM connector when it is monitoring that pin. To explain further, the PCM looks at it's control lines to see if the item is still connected to the PCM. It should see 12 volts there prior to commanding the solenoid to come on. It then commands the solenoid on (if it's there) by simply pulling the line at the PCM to ground. Since one side of the solenoid has 12 volts all the time the other side of the solenoid (the side connected to the PCM) must be pulled to ground to make it power up. Understand?

What the PCM is telling you with a DTC84 is that the PCM black connector pin 13 (the one with the white wire) is not seeing the 12 volts that should be there when ever the ignition switch is on.

So here is what you do.
Pull the black connector off the PCM. Now key on engine off. Probe the 13th pin for 12 volts. If it is NOT there, you now have to check the wiring for faulty connection or a break some where. If 12volts is at the trans connector. Then check the solenoid for continuity from pin E to S of the transmission connector. The solenoid may be bad. But don't simply replace it. Check it for continuity before you do anything else. Your entire problem with this circuit could just be the fact that you have a vehicle that is 17 years old and has a poor connection.

If on the other hand, you find 12 volts at the black PCM connector let us know.

Dave

 

UnfortunatEly it has 12 volts, is this leading down a bad road? It's starting to sound that way unfortunatEly. So now that I have 12 volts but also, iver replace the 3-2 solEnoid too. So what r your thoughts now? And thank u for the help. Really, I appreciate it a lot.

 

You're saying that 12volts is at the correct pin at the PCM and you have an active 84 code?

Have you cleared the code and it has returned? Try clearing it and let us know if it returns.

 

No I haven't cleared it, I will do so, and let u know. Thanx for the help again. The dmm shows 11.9 in that pin. That's close enough with the key on and engine not running isn't it?

 

Yeah 11.9 is ok for now. But that brings up another point. You need to check battery voltage while the key is off, key is on but engine is off and last see what the battery voltage drops to while someone is cranking the engine.

 

BattEry voltage is 12.6 and when the engine is running the voltage is very eratic, it bounces everywhere. Should I look into a new alternator? On nissans that's normal, but idk with an lt1. The voltage whike it's running will fluctuate from 15.2 all the way to 9.6, and it bounces fast.

 

Didn't ask about all those other voltages. Your meter bouncing around doesn't mean anything either.

do you want to get the other 2 readings I asked you about?