karkareco

i have a problem that i cant seem to get right..what i have is a 94z28 lt1 that i bought with a bad trans...i bought another z28 that was wrecked but still drove but it was a 95 with a documented 4000 mile trans in it..i drove that wrecked one home and then pulled the trans and the pcm...i put the trans in and during my research i found that the trans i pulled out of it had already been replaced with a 95 pwm trans..i added the wire from d6 to pin u on trans connector and sent pcm to lt1 tuning and had a 95 base tune put in the 94 pcm for the trans..got it back and it was throwing code 84 for 3-2 downshift feedback fault wich it also used to have with old trans..i tested the soloniod and even tested it through the harness to the pcm and ohmed out..still went ahead and replaced soloniod and still code is there..then made up test harness and still code is the same..then i tried the 95 pcm and it didnt have the code 84 anymore but it has code 83 torque converer quad driver module with test harness or with the one in the car...leads to believe that problem is in the pcm..maybee the tune?kinda crazy that bolth pcm would have a problem and similar but different..i have tried everything and am so stuck so any help would be more than appreciated..ill owe ya bigtime,,you have my word on that

12SCNDZ

There are 2 different 3-2 solenoids with different ohms...They changed them in '96. For a '94-'95 you should have a solenoid with a white/tan connector with a STEEL stem that protrudes into the valve body (NOT PLASTIC). It could also have a later solenoid with a gray connector.

Frank

karkareco

it does have the steel stemed one i thought about that if the soloniod in the trans is for the 95 plus pwm setup maybee the pcm i have for the 94 that was tuned doesnt have pwm cabability and only can turn on and off wich would match the old trans from 94..and if it was a soloniod problem and the tuning is proper i would think i would be throwing the same code...its the craziest prob ive ever had..it was 9-14 ohms on the 3-2 downshift and torque converter clutch pwm soloniod and the torque converter clutch soloniod was 20-40...

12SCNDZ

Both solenoids on a '95 are the same.

Frank

karkareco

put together today and no codes left and finally shifts through all the gears..although it seems slow to engage reverse?any thought son that

12SCNDZ

Could be too much clearance in the low/reverse or reverse input clutches.

Frank

karkareco

you had said that bolth soloniods on a 95 are the same..wich are you talking about?i have rechecked and the tcc soloniod has 19.2 ,the tcc pwm soloniod has 10.6 ,the 3-2 downshift soloniod has 10.8,the 1-2 and 2-3 bolth have 20.5 and thats checking from pcm harness connector at the pcm so i am checking wiring and soloniods all that seemed to be right in the proper range according to shbox website..still has the slow to engage reverse but it didnt have that before switching trans and also with the reprogrammed 94 pcm it will throw the code 3-2 downshift and go into 3rd gear limp mode but with the 95 pcm it will shift through all the gear but has check engine light and fan on but when check codes it says no codes found..if i goto clear codes anyway it will turn light off and fan off for a sec and then right back on..i have replaced the 3-2 downshift soloniod and same problem..also i noticed on the passenger side front of harness there is another plug that just hangs there for another soloniod..old trans didnt have that?just a little more info..my brain is cooked

12SCNDZ

Both the PWM and 3-2 solenoid should have 10-15 ohms...