2003 Chevy Silverado Stuck in 2nd Gear

[Quintin4187]

I have recently experienced issues with my 2003 Chevy Silverado transmission. The first experience after owning the truck was the truck would intermittently not shift into overdrive.

I check fluid level and found overfilled a little. Tried to drain extra fluid out but drain plug was stripped. I drove truck for another month and had then noticed truck would take off in what seemed 2nd gear and still no overdrive. The overdrive was no longer kicking in. I could manually take off in 1st gear for power and then shift back into D. I drove it this way for a couple days on small trips, (10 miles). On one specific trip back the hose going to transmission cooler blew off. It was small black hose and I cut off end and reinstalled back on. In the process I filled back to correct fluid level and put in 1 quart of Lucas tranny fix. I drove for a day with no issues, the transmission shifted as it should with no problems.

The following day I went and took truck out and found that I lt wouldn’t shift into 3rd gear or 4th manually or through D. I pulled codes and found “ solenoid a, solenoid b electrical, and torque converter faults. These codes may have been present for a long time and I had not checked codes since I owned truck. I cleared codes and took for test drive again to try and get new updated codes.

The truck would shift up to 2nd and then act like it goes into neutral when shifting to 3rd. Same issue when manually shifting into 3rd. I checked codes and no codes other than Evap system faults. I decided to drop pan change fluid and filter with new. While I had pan off I removed solenoids A and B and tested with 9v battery and solenoids were working properly. Solenoids cut off flow when power attached. This let me know the solenoids we’re doing their job.

I then used a friend of mines truck that was exact make, model and year and replaced throttle body in hopes that issue was TPS related. Started truck and truck actually ran worse but same transmission issue. Reinstalled throttle body and swapped his PCM with mine. Same issues with no changes.

I’m looking for any other ideas for diagnosing and hopefully repairing this thing. Does it seem be an electrical issue or mechanical that needs rebuilt? I have drove it a couple times on test drives about 2 miles or so with no new codes popping up.

After letting truck sit for about a month started truck drove about 2 miles to check codes again and found these codes active. Did a little hunting and found that these are common and usually a result of a wire broken or fuse blown. These codes weren’t active until the most recent test drive. The truck now when put in “D” will take off in 1st but never shift any higher. I can then manually put in “2” and it will shift into 2nd gear. 3rd,4th and OD are still inop at this time.

I figured I would also add in although probably not related my gear shift select light is very dim, only reason I mention that is other people that posted with this issue also had dim shift light. I listed below the codes that are currently active that are transmission related. I can take videos or pictures of truck if needed to help diagnosis.
P0740
P0753
P0758
P0785
P1860

 

[mrrsm]

When the Codes you listed cluster together like this... The First Suspect to look at is a Faulty Ignition Switch. The reason is the Power for the Transmission Solenoids or Sensors comes off of The Pink Wire coming from the Ignition Harness. Before you perform this Ignition Switch R&R ...refer to some of the "How To" Links on what to do with this job at GMT Nation. Some of the problems that can arise during this repair involve:

(1) Choosing a Non-OEM Quality Replacement Ignition Switch ...and

(2) Mis-aligning the Rotating Gear Teeth in the Ignition Switch during the R&R.

It's AC-Delco ...All the way on this Part, Brother. You don't mention it... but has your battery been drained down mysteriously of late? If so... the Bad Ignition Switch might also be involved there as well.

Just an FYI... Your first post is very nice detailed; which is not very common... But If you can... Take Pity on your Readers with a paragraph break very 1.5 to 2 inches or so.... as Digesting and the Returning to the Key Features later on will make life much easier for the many Members who will want to offer you some help. Welcome to GMT Nation! :>)

 

[Quintin4187]

Thank you for the reply, after reading back over my post I did notice it was pretty lengthy. I’ll make sure and edit to make it easier on the eyes lol.

As for the ignition switch causing the issue with the common cluster of codes most of the “how to’s” we’re SUV related and direct you to check the fuses under the seat. I’m assuming the same fuse box for the Silverado is located by driver door and I’ll check power there tommrow and at transmission plug.

I know assuming isn’t the best idea when trying to diagnose an issue like this but I have a hard time believing that the two issues are related. The reason being is that I never had those codes prior to letting the truck sit for a while and transmission was acting up before the cluster of codes.

I’ll check the ignition switch issue tomorrow and update my post. I’ll fix that issue and then move on to the next if that doesn’t fix my transmission. I really appreciate the help and look forward to hearing back!

 

[Mooseman]

When multiple codes appear for the tranny like that, it's usually a connection or ground issue to the tranny or a wiring issue. Could also be an electrical issue inside the tranny. There is one of the PCM fuses that supplies the tranny so be sure to check power there. Grab the manuals in my signature and check the schematics. You might have to check for continuity to each of those wires.

 

[mrrsm]

This link explains the reason in part for suspecting the Ignition Switch (with echoes of what @Mooseman is suggesting on measuring the Battery Voltage to the Transmission Solenoids from a Fused location). Many of those codes pop because in a situation of Low Voltage... The Transmission Solenoids simply cannot function properly...ergo... no correct shifting as a result:

http://www.silveradosierra.com/transmission/03-silverado-will-not-shift-t88089.html

 

[Quintin4187]

Ok, so you guys are great! I pulled my ignition switch off and took the covers off the switch found that the center point was burnt. Swapped my buddies ignition switch with mine and took on test drive truck.

I put the truck in “D” and truck takes off in 1st gear and properly shifts into 2nd gear. Truck will then try and shift into 3rd gear but over rev and seems like it goes into neutral.

So this actually fixed half of my issues. I’m no longer getting any transmission codes but I’m still unable to shift into 3rd gear and on.

I actually took my ignition switch apart and cleaned off the points with sandpaper reinstalled and now my ignition switch is as good as new, and no fault codes with my old switch.

So now I’m trying to try and resolve this 3rd gear issue. Any help is appreciated. I’ll post a video of truck starting out in “D” and driving down road.

 

[mrrsm]

Did you clear the Old Codes prior to taking a Test Drive and then re-check for any New Codes? The P1860 and/or (P1870) problems should be investigated and repaired if necessary after using a Digital Multi-Media check on the TCC Solenoids. The other possibility is that depending upon the Truck Mileage and use for Towing or Harsh Treatment on extreme inclines... then the 3/4 Clutch packs might be worn badly enough to warrant replacement. But first, examine and test the TTC and other harness issues. If necessary... replace the harness and solenoids first as it is the least expensive and most logical problem to solve first and a lot cheaper than having to pull the Transmission to have it torn down.

Others members might also recommend purchasing a Master Solenoid Kit that follows as the second or third video after you watch this first video. Download all of the Videos for training and reference purpose and become as familiar with the supplies and tools you will need for the complete service shown in all of them. Before proceeding... please double check all of your pending codes and list what you discover here about each one and any actions you have taken to address each one ...in the Order They Appear. Please don't skip any of the steps to solve each one in this manner... In Order:

Master Solenoid Kit R&R How To:

 

[Quintin4187]

Yes, I had cleared the codes prior to test drive. During test drive no codes popped up and truck shifted "correctly" from 1st to 2nd. I forgot to mention earlier to verify that the ignition switch was the issue I checked codes and found no codes after first test drive. I then reinstalled my bad ignition switch and took back on 2nd test drive and found that codes popped back up and truck was shifting incorrectly again. Removed ignition switch reinstalled my buddies, cleared codes and no codes popped up on what was 3rd test drive. This lets me know that the ignition switch was in fact causing the codes and no shift into 2nd from "D".

I'm starting to believe that I do in fact had a worn 3-4 clutch pack. I will drop pan next and ohm out solenoids like you mentioned earlier but that leaves me wondering if the solenoids themselves are good, but the truck is just not able to send the signal to the TCC to allow a 2nd to 3rd shift. I checked under Moosemans signature for schematics for transmission plug, but unable to figure out a way to check continuity from tranny plug to PCM, ( i'm assuming that's where the signals comes from first)

I also did stumble across a pretty handy PDF file for transmission removal and rebuild instructions i'll upload. I was unable to upload video i took of truck running due to large file sadly, but i'm not sure it would help anyways.

Scratch that, also unable to upload PDF file as it was too large as well, ill just post link.

https://www.uscars.biz/uscars/extras-documents/ATRA_GM_4L60-4L60E_(700R4)_Rebuild_Procedures.pdf

 

[mrrsm]

I mentioned early on how impressed I was with the facts and details that you took the time to list in your opening gambit on these problems. The Operative Word to consider first is what you described as being "intermittent". While you may well have a problem with the 3/4 Clutch Packs that might merit an R&R and a Rebuild or perhaps a swap with a re-manned warrantied flavor... What happened here as being sketchy behavior on shifting to and from Overdrive deserves a thorough thrashing about for Electrical Causalities first.

If the TCC Solenoid is short circuiting... it would affect all of the other Solenoids on the harness as well. Scour Youtube to find as many Videos on the TCC R&R and The Master Solenoid Kit and while doing so... locate a new OEM Wire Harness as well if you go to the trouble of installing the Kit and the wiring. If all of these problems go away... you will be saving yourself an awful lot of grief and money by doing so. Re-Building a Transmission as elegant and interesting as the GM 4L60E Transmission is Cool ... But it can also become a Very Long Road ...with No Turns In It. So unless you just want to take on all of that... work the present problem(s) as though they are all electrical first and lets see what happens. If you decide to perform the TCC Solenoid R&R first, then later you can perform the Master Kit installation if necessary if your first go at it does nor solve the problem. Performing Transmission Repairs are like Eating Elephants... Both are Best Done... Only if Necessary ...and One Bite at a Time.

EDIT:

While this video involves a related repair on a Chevrolet Blazer... The commonality of the 4L60E is good enough to allow you the chance to watch these guys diagnosing and performing the Solenoid R&R...and enjoy their efforts without getting Transmission Fluid spilled into YOUR Eyes... :>)