4L60E Problem

I have a 1999 GMC Sierra with the 5.3L engine and 4L60E transmission. I only have 2 forward gears and reverse. I have changed the fluid, filter, and both shift solenoids. I have seen a lot of posts about "limp-mode" but not enough information on how to get it out of limp mode if that is the problem. Thanks in advance for any help or suggestions.

Make sure the main plug on the trans is in tight and the connections are clean. Also make sure you have power to the plug, If all is ok, you need a full scan to see what is happening internally.

have you ever heard of limp mode? if so what is it and is there fuses or something else that i need to reset to get it out of this mode?

pull the negative battry cabe for 5 minutes , should reset , if it goes back into limp mode , have it scanned at a tranny shop,could just be a sensor or the tranny is shot

Limp mode is a pcm default when a solenoid is unpowered or the pcm sees a fault in the trans and allows it to stay in 2cnd for " limp" driveabilty. did you do what I posted, there is no quick resolution to this.

i have not checked the plug yet. have to find time to do that. replacing the solenoids took longer than expected. i have read many time of people having the same problem and replacing the trans and still having the problem. i have checked or codes and the scan showed nothing. how would i determine if what a few people have said about the ignition switch causing the problem?

No power to the plug on the trans.

Any resolution to this problem?

I have a similar situation except that when I pull the plug and shoot the connector with electrical contact cleaner, I get first gear back for a few days. I am thinking the fact that I am disconnecting the plug causes something to reset.

A scan with a trans function scanner can look at internal solenoid functions.

I have been thinking of getting an OBD scanner, any suggestions on one that would also scan transmission codes for an '94 fullsize blazer?

You need a professional scanner to get into the trans, a $300 obd11 will not work.