2001 Monte Carlo SS Transmission

[monteheeren]

Recently purchased this Monte Carlo SS with a bad engine. Picked up a really good engine and it sounds great. Backed the car out of the garage, and when I shifted into drive, the car would hardly move. It felt like it was starting out in high gear. Had code P1860 (Trans converter clutch) set. Car has 150K on it. Suspected bad trans. Just had the trans rebuilt by AAMCO to the tune of $1100.00. Still have the exact same problem. The car will go in reverse just fine, but it won't hardly move forward. The old engine pushed a lot of antifreeze and oil through the exhaust. When I started the new engine, it smoked like a smoke stack for about 20 minutes, but then quit smoking. What am I missing? The trans is full of oil, and all connections are fine. Any help would be appreciated.

The Monte Carlo is a 2000, not a 2001.

[thisnametooktolong]

what tranny do you have in that thing?
That Monte has the 4t65E transmission in it? Check the fuse for the 12 volts to the transmission. Make sure you have 12 volts to the plug. In any event it sounds like it has low line pressure or the A solenoid is not working. When you manually shift it into 1st gear does it go? Those trannys are shifted with a ground signal that turns on valves that are controlled by the ECM.
The default gear for those transmissions is second gear when it looses the fuse, so it would feel like it is starting in high gear.

I think that 1999 was the last year for the 4t60. If it has the 460 try unplugging the modulator valve. That will jack the line pressure, and poof it will go into 1st But it is also shifted by the ECM

[monteheeren]

Thank you for the reply. Pretty sure its the 4t65E. The tag says LMB.
Have not checked the fuse. When I put it in 1st gear manually, it does seem better. I trailered the car to AAMCO to have them diagnose it. I'm going to feel pretty dumb if its only a bad fuse. AAMCO always dyno's there trannys before they leave the shop. The problem has to be on the car some place.
Where is the fuse? Under the hood or inside the car?

[thisnametooktolong]

Most GMs do not have the tranny fuse under the hood. They are usefully in the passenger compartment. One of the reasons why I told you to check for power at the plug was because in a old buick the wire was broken. The fuse was good but there was no power to the plug.

[monteheeren]

Problem solved! Took AAMCO 2 days to diagnose, but they found a broke wire in the main wire harness from the engine to the car. I would have never found it! Car runs like a new one. I learned a good lesson!

[ahardesty93]

hey monteheeren! I know its been awile ago since you posted this article, but do you remember what wire was broke (color or location) im having the same issue with mine.

Thanks Aaron

[monteheeren]

Aaron,
AAMCO found the problem. It's the big wire harness connector on top.
Tug the back of each wire and make sure it's not loose. Drove me crazy.