I am new to Blazer Forum, i just bought a 1994 full size Blazer, 350tbi 4l60 trans, the trans will not shift at all on its own but will go into 2nd when shifted into 1st or 2nd, and will go into 3rd when shifted into D or OD, revese works fine? Any thoughts would be appreciated.

 

Are you sure that it is the 4L60 and not the 4L60E (electronic version of the 4L60/700R4)?

If it is the 4L60E, then the problem is most likely caused by a faulty 1-2 shift solenoid. Easily replaced by dropping the pan.

 

Thanks for answering, yes it is 4l60e, i was assuming the same and have now replaced both soledoids and have had no luck. Both are getting voltage and checked out good before i even replaced them, there was virtually no wear on the trans and seemed to be in good shape, i swaped them in the case 1 might just be weak. the ses light is on and i noticed that the obd1 sys and the shift solenoids share some wiring, could this be the culpret? no one around here seems to have a scan tool for the obd1 sys?!? they say that stuff wasn't hard to figure out?!?! All replys are welcome, thanks every one

 

Power is supplied to both of those solenoids from an ignition source. The grounds are controlled by the ECU. If there is a problem with the wiring, the ECU would not be able to properly ground the solenoid.

 

You may have to bite the bullet and take it to a QUALIFIED transmission shop. If the solenoids are good and getting the proper signals then it may get real expensive real fast.

 

A scan tool for OBD1 systems can consist of a wire that grounds ports A&B on the diagnostic terminal and turning on the key to watch how many times the ses light flashes and pauses you can use a paperclip to get codes. and I am sure the codes are easy to find on this site.

 

i tried the paper clip method with no blinking, i went and bought a scan tool and it says it cannot connect with host but works fine on my odb2 2002 z28, the ses light just stays on. could all this be something in the igniton switch or steering column, when i got it all the bolts on the tilt were about to fall out and he said he had been driving it like that for about 6 months, how would i be able to tell what wires do what and which need power, any help would be great, i changed both solenoids with no improvment, when i changed the one on the driverside of the trans it came out like normal, the one on the passenger side shot out of the trans with alot of fluid and pressure behind it, is that normal cause i never seen it before, thanks everyone

 

just wanted to follow up and let you know what was wrong. i have been on vac for the last week, i assumed the ecu had to be bad after everything checked out, i pulled the ecu to find a replacement and decided to make sure the prom chip had not came loose and discovered that there was no prom chip? at some point some one stole the chip and never replaced it, took 3 owners for me to fig it out, $65 fix from ebay, found two identical ecu w matching prom!!! thanks for all the help