i have looked at the bin in post 30 and your good to go as far as using "95 pwm code". your problem lies elsewhere.
Printable View
i have looked at the bin in post 30 and your good to go as far as using "95 pwm code". your problem lies elsewhere.
Thanks for looking at it and apologies for the tardy reply. It's been... busy. With stuff I haven't wanted to deal with. Anyway, I'm thinking my next step will be to pull the harness out of the trans and see if anything unusual was done with it by the unknown builder. Bummer I don't have a known good 95 4L60E lying around, lol. I'll go out on a limb and speculate that maybe the builder put this thing together with something different electronically to sell it to buyers with 94 cars. If the trans was a bill of goods, what I've done should have worked, adding the wire from PCM to PWM solenoid and switching to 95 code.Quote:
Originally Posted by jthompson122183
I fished the case connector from the trans up to the engine bay. I'm going through the transmission wiring harness with it out of the car, connected up top so I can troubleshoot everything inside the trans as an assembly. It appears to be a reused OE harness because it only has one connector for the 3-2 solenoid. Aftermarket harnesses have 2 for the 3-2; one for 95 solenoid, one for 96-up solenoid connector.
Confirmed the valve body has a 95 casting mark on it so at long last that's confirmed.
All the tuning help I could have needed to address my problems with this thing I got here. Thanks again to all who reviewed my work. I thought I'd at least come back with the outcome. I'll post up the results of the electrical troubleshooting soon.
You may have a mechanical problem with the PWM valve and bore wear in the valve body. Another issue may be that the PWM (95-newer) transmissions use a different tcc spool valve in the pump. If your trans is a 94 w/a 95 valve body and no tcc valve swap, you can have all kinds of issues w/OD and lock up.
Thanks for offering additional insight! I should have mentioned that the case is a 95 K case and the pump does have PWM stamped on it and it was equipped with a 3-2 control solenoid appropriate for a 95. So on the surface everything seems to match as a 95 aftermarket built transmission. The transmission has about 1000 miles on it at most. I do see some friction material shed into the transmission from being driven with the 3-4 clutches getting extra wear as a result of it being driven by a 94 PCM and no control of the PWM solenoid (now corrected in the 95 tune and extra wire run to control the PWM control solenoid). I'm hoping that no mechanical problems due to wear in the valve body bores has arisen yet. I've accepted that if I get it operating error free, I'll have a transmission with some accelerated wear on it (like 20-30,000 miles of wear in less than 2,000 or something). Maybe higher simulated miles or worse damage than expected.Quote:
Originally Posted by Tom B.
I'll be getting back to it later today and hopefully have some more answers.
Values in ohms are:
1-2 shift 21.2
2-3 shift 21.9
Press. Control 4.6
3-2 control 11.4
TCC 23.8
TCC control 11.2
Here's the bench- notice the PCM removed so I can apply voltage down the wire to pin E and ground through the PCM connector pins for each solenoid (except the pressure control solenoid). PCS can be tested with a 9V battery briefly. Testing from PCM down to solenoids gives me more confidence things are working. Honestly, I'm hoping to find something wrong with the harness and just replace it and be done.
I tested all the solenoids except the PCS, will have to dig up a 9V battery for that one, but I did check the resistance between the PCM pins that go to it (no direct 12V from pin E, only gets signal from PCM).
The 3-2 is the newest solenoid since I replaced it back in 2011 when I first encountered the issues. The PWM solenoid click doesn't sound nearly as stout as the 3-2. They are 2 different manufacturers, the PWM has been in there since before I got the car.
Here's the kicker- the TCC solenoid (built into the harness) does NOT click for me. I can't find a definitive answer as to whether it SHOULD make an audible click, but I'd at least think so. I tested 1-2, 2-3, 3-2, TCC, PWM with IGN239 circuit hot with PCM disconnected and used a small wire to ground the PCM connector pins at each solenoid's PCM location. To eliminate the engine harness I went through the case connector on pins E and T straight off the battery. Again, the TCC solenoid does NOT click. Its resistance is still at 24 ohms after this testing through PCM connectors and direct to battery.
I picked up a new harness with TCC solenoid. BWD S9844. Has Delphi printed on it in a couple places. Same manufacturer overseas makes a bunch of Delphi stuff these days, all the same. I tested the new harness the same way as the old one and this time I got a nice loud click from the TCC solenoid. Got the car all back together, just have to fill up the fluid and let it rip and scan for codes. It's too loud to fire up after 9PM in my neighborhood. Answers tomorrow. If it's fixed I'll learn to dance a jig, lol.
Tentatively going to say it's resolved. But not how it thought it would be.
Yes, the harness needed to be replaced due to the hidden issue with the TCC solenoid built into the harness. But that wasn't the cause of the code 84 3-2 downshift circuit problem that kept it in limp mode. I replaced the harness, buttoned it up, filled it up and crossed my fingers. I used GaryDoug's Scan9495 utility to monitor for trouble codes and the code 84 almost immediately popped back up. I'd clear it and it'd come right back in 2-3 seconds. Looking at the electrical faults tab in the program, it made me think from another direction when it said 'open circuit' on the 3-2 downshift solenoid circuit. I have a spare PCM...
The spare was from a 94 Z28 with 3.23s. So I threw it in and fired it up and scanned again. No codes, no circuit faults. The current PCM threw the code 84 under both 94 and 95 calibrations. I ran it for almost 20 minutes on the spare- no codes, no faults. Ok, so I can't use a 94 tune on a 95 trans. My 16210041 calibration ID on the PCM I've been using all along has the 95 code and some small mods for O2 relocation, etc., and has good data. Could the PCM internal circuit traces for the 3-2 circuit be damaged?
I set up my flash bench and uploaded the tune to the spare PCM with EEHACK 4.7 :thumbsup:. Threw it back in, crossed my fingers and... no codes. took it for a run around the block. Amazing to feel first gear in D at normal line pressure. I'll take it for a longer drive later and see how it goes. But it's never run for more than a few seconds before throwing the code 84 and now I've had 2 run cycles of nearly 25 minutes with no DTCs. I never considered the PCM might be at fault.
The mail order tune I got in 2010 was useless garbage and the reflash was good money after bad but it put me on the track of finding the hidden TCC solenoid problem and I learned more about the 4L60E. Way more than I wanted to actually, but it was good to learn.