1998 C2500 4L80e Transmission Has 3rd Gear and Reverse Only
- Thread starter PrchJrkr
- Start date
Back in the day, I could too, but it's an old state road truck. They get serviced, not like Bubba down the street. Bubba says if you change the filter, it's gonna start slippin' and the fluid is lifetime fluid. You don't have to change that!Coulda swapped out the whole tranny by now....
Bare-ya-cuda
Well-Known Member
Similar issue a couple years ago with a 4L60E and it turned out to be the valve body.
Bare-ya-cuda
Well-Known Member
Also are you sure it’s a 4L80E? 1998 should be a 4L60E.
Yes, positive. I deciphered the code label. It's a C2500 with a 350, 4l80e, 3.73 posi, and semi-floating rear axle and 8 lugs.
The new solenoid looks more like the original equipment with no cheesy pigtail and is made in USA, however, the fluid port is missing a strainer screen. I tried to extract the screen from the original, but it appears to be molded into the plastic. My parts guy told me over the phone that the inner packaging was opened, but it didn't appear to have been installed/returned. I guess along the line it was returned to the store and not written off as defective for missing the screen.
Begin round three...
Round three, new solenoid received w/o a strainer screen just like the last one. I'll be swapping it out today to see if there's any change. If the new solenoid doesn't fix the issue, I'm going to go over every inch of the wiring harness and inspect, clean, and reseat connectors. With the forecast calling for rain/showers all day, I plan to make the most of it.
What part number are you using for getting a replacement? A quick search indicates that an OEM number would be 24230288. Is this what you are looking for - https://www.rockauto.com/en/moreinfo.php?pk=452556
That's the one. I shopped locally, because I has too impatient to wait for delivery.
Both solenoids are reading right around 23-25ohms where 0-40 is the range. I tested continuity between the ECM and the transmission harness. It all checked out. I installed a #2 ground cable between the bell housing and frame. I'm still looking for the simple to fix things first. The thing has been maintained well because it was a municipal truck. It gave no signs of wear/age like slipping, just poof, no shift. As soon as I start it and move the shift lever, it pops a P0758 for solenoid B electrical. Grrr...
The Powertrain Control Module (PCM) controls the solenoid by providing the ground path. When the Powertrain Control Module (PCM) detects a continuous open, short to ground or short to power in the 2-3 Shift Solenoid (SS) valve circuit, then Diagnostic Trouble Code (DTC) P0758 sets.
Reading a bit on this and it could be either the PCM or the C2 Red connector at the PCM. The 2-3 shift control signal should be at pin 4 yellow with black stripe.
Reading a bit on this and it could be either the PCM or the C2 Red connector at the PCM. The 2-3 shift control signal should be at pin 4 yellow with black stripe.
Thank you. The red connector on the PCM/ECM is where I was testing the connectivity from, down to the plug on the side of the transmission. The PCM/ECM is the part that I was trying to avoid replacing, because it's my understanding that it must be programmed. This truck is #3 in my line up and will probably be sold, once I get my Trail Blazer up and running again. I just gave Rock Auto about $600 for P/S hoses, P/S cooler, fuel pump, and misc parts.
I'm at the point where this item may be the answer. I could mount it in the dash and manually control the solenoid grounds. 
The Answer
The Answer
Most of the sites I've been to say that it should only be one hour of shop time to diagnose. If you have "creep" mode it might be worth it to have someone check it out.Thank you. The red connector on the PCM/ECM is where I was testing the connectivity from, down to the plug on the side of the transmission. The PCM/ECM is the part that I was trying to avoid replacing, because it's my understanding that it must be programmed. This truck is #3 in my line up and will probably be sold, once I get my Trail Blazer up and running again. I just gave Rock Auto about $600 for P/S hoses, P/S cooler, fuel pump, and misc parts.
Bare-ya-cuda
Well-Known Member
similar issue in a 2001 4L60E, i went through everything before i changed the valve body which fixed it. Likely have band material causing a check ball not to seat causing line pressure to be low. low pressure and the solenoids will not work correctly causing a code. Valve bodies are readily available online remanufactured. I changed mine on my back under truck. Just have to ensure you have transmission jelly in the check balls to prevent them from falling out, mine came with it. it is also imperative that each bolt go back in the position it was removed from. different lengths and a long one will block a passage and likely burn up the transmission. you can also check sonnax website for troubleshooting write ups.
Damn it! I clicked on your link and now I'm getting emails from eBay asking if I want to purchase it.I'm at the point where this item may be the answer. I could mount it in the dash and manually control the solenoid grounds.
The Answer
Well, it is a good deal.Damn it! I clicked on your link and now I'm getting emails from eBay asking if I want to purchase it.