1997 suburban battery disconnect=transmission issue help please

Christopher Replogle · February 4, 2020

So I have 1997 suburban 1500 2wd 5.7l went to install a train nor the other day didn't get around to it I might add. Had battery disconnected for a bit. Next day it started out driving fine. Felt a wierd flutter going down the highway. Stopped at the store and could barely reverse took basically sitting on the pedal keeping rpm a little over 1200. Went in to drive just fine. By the next stoplight take off felt sluggish. Now it will barely get to moving at all. Electrical issue or what???? RpMs solid at idle around 650, doesn't have the mysterious rough idle or anything like that chased that's thru a full engine rebuild just about with my last suburban. Haven't had this one too long but seemed well taken care of I'm the second owner a school had it before me. So I figure all the maintenance was kept up. Got about 145,000 miles on it trans fluids clean and around proper levels. Any ideas would be greatly appreciated. I'm hoping its not a transmission failure don't see that just happening out of the blue without prior signs or behavior

m&jtrans · February 4, 2020

Could be the trans module on the side of it. Check the plug see if its clean. Some parts stores have testing equipment but I'm not sure about testing that module

Blue Mule

Christopher Replogle · February 4, 2020

That's what I thought at first. But when I started researching it everything I seemed to find pointed forward it have a power train module built in with the ecm. I may be wrong thou I'll have to check it out. One wierdthin I noticed is if I take my multi meter and run it from a ground to the transmission pan it reads out at .400 milliamps I believe its only supposed to read out at .300. I have an obd2 reader heck even the computer software i m just not to great with electrical to know what I'm looking for one thing I noticed in diagnostics is I had a tie $07 did $0c and tid 07 cid 0d which are both gm specific leading back to low voltage measurement at test cycle relating back to egr an map sensor figured they could just be do not having been able to complete a drive cycle since the battery had Ben disconnected

BlancoSilverado · February 4, 2020

~~I know on my older truck if i disconnected the battery it would automatically shift into 4HI. might want to check that out.~~

Just realized you have 2wd. sorry cant help.

Edited February 4, 2020 by BlancoSilverado

djjdave1 · February 4, 2020

hiya, this is Dave, I have a 99 gmc 3500 4wd crew cab with the 7.4 vortec. I had tranny issues at one point too, found I had some grounding issues.

Truck started right up, so my neg to the block was good, but I had found cab to chassis was rotted thru. So you might want to get a braided ground strap from the parts store and go from the block to the firewall. Also check the grounding of where the ECM is located, which I believe is on one passenger fender. There should be a ground wire from the battery to either the inner or outer fender. Again, corrosion/rust could be playing tricks with you electrical system.

Do you have the 4L60 transmission? you may want to check the shift box on the shift shaft of the transmission. It may not be sending the signal to the computer that controls the shift solenoids.

hope this didn't drive you crazy' Dave

Christopher Replogle · February 11, 2020

So update, found the transmission problem the filter had came loose in the pan. Made me feel like an idiot. She drives great now but has developed a mind of her own now she just stalls out randomly. There's times it will start right back up and other times its a battle to get her going again mostly happens when parked right after a drive but sometimes upon cold start and a couple times when I was driving any ideas?