2007 Silverado Classic, 155K. 5.3L (Auto trans, 4L60E I think)

I recently had the transmission serviced with a fluid change and a new pressure switch and had that installed.

Now, on occasion, the trans is stuck in 2nd gear, meaning it starts off in 2nd (Drive selected) and stays there. The other day I went to get some firewood and it was shifting fine. As soon as I loaded the wood in the bed, I selected Drive and it felt sluggish until I realized I was in 2nd gear.

I got home with no problems, turned it off, re-started it and it then worked normally.

No Check Engine light or active codes are present with my OBDII scanner.

Any insight would be appreciated.

 

It could be an intermittent issue with the PCM. I am only making an educated guess here, without knowing more.

 

@oilcanhenry Thank you for the reply. I had the truck out on Saturday and everything appeared fine. Then all of a sudden @55mph, it downshifted into 2nd gear from 4th. I stopped for a bit. Stopped the engine and re-started. Then the Check Engine Light came on.
The drive back home was uneventful as it shifted normally. I hooked up my scanner and it showed a P1810 code. (Transmission Fluid Pressure (TFP) manual valve position switch circuit). I had a local mechanic replace that switch a few weeks ago with a new filter and tranny fluid.
Should I maybe remove the battery to reset the PCM?

Thanks,

RickR90s

 

On the off chance it might be the transmission control module, can I ask where it would be located? (2007 Silverado Classic, 5.3L V8)

 

It should be located on the driver's side fender well, underneath the battery, with a black plastic shield. Also, you might look into the PCM relay being possibly being bad.

Part number is ACDELCO 13500114. I hope that will fix your Silverado, as the PCM's are costlier and harder to change then a minus $10 dollar bad relay is!

 

All I can say is that it's worth a shot, and only a bit of time, but no guarantees. Might have to reset the clock, radio, ect, but I've seen it work sometimes, but every vehicle is different, but as they say, "you don't know until you try."

 

Thank You very much! I found another module on the driver's side firewall but that definitely wasn't it.

I'll check into the relay and TCM today after I remove the battery.

I've changed trannies in the past but I'm a bit older now and not as inclined to crawl up under my vehicles.

 

Best of luck to you. I too am not a young man anymore, but if I can get to the part I can still work on it. I just changed out my niece's 2005 VW Tourag 3.2 liter WATER COOLED ALTERNATOR. Never saw anything like it before or since. I don't know WHY VW had to use water cooling, instead of air cooling, but I won't touch one again. It was a real pain in the **** to change out with coolant lines.

 

I removed the battery over the weekend but I'm not seeing any kind of module below the battery tray.

Please see attached photos to help me determine which is the Transmission Control Module.

Appreciate the help,

RickR90s

 

try punching the numbers on the modules into Google.