Hey guys, I'm new to the forum. First Post! I came across a video of a guy working on a Trailblazer that was having the EXACT 5 transmission solenoid codes as I do, as well as the same symptoms. Had my transmission rebuilt in January 2019. It worked flawlessly until November 2019. Got in the truck one day and it was like i was taking off in 3rd gear. Stopped and turned the truck off, restarted and it was fine. Called transmission shop and they said maybe some trash went through a solenoid, but if it did it again bring it to them since i had a 1 year warranty. Truck did the same thing a few days later. Carried it to the transmission shop. They called the net day and asked if i had added anything aftermarket to the truck because it gave them all 5 solenoid codes at one. They said that the trans was mechanically fine, and that i needed to start tracing wires. Checked the obvious things like the ground under the radiator, and the ground under the bed behind the driver door. Checked connector to transmission and it had trans fluid inside the plug. Cleaned out the plug and thought this was the issue. It was not. Same symptoms a few days later. Just been driving it and resetting it by turning the truck off and starting back. Recently however the truck is doing it more often and becoming harder to reset. The video about the trailblazer that i saw last night talked about checking fuse 47 under the back seat and then working forwards or backwards from there to find the issue. I pulled up a wiring diagram online that i think is for my truck. I saw, just like he said, that there is one wire that powers al 5 solenoids. So it makes since that me having all 5 codes means i am losing power, intermittently. But, what fuse is that on the 03 silverado 4.8 2wd? i looked in the fuse panel beside the driver door and checked the "TBC IGN 0" fuse while the truck was running and i had 14.2v on each side. Is this the right fuse, if so, where do i go from here? Side note, i changed the ignition a few years back when i was having shifting issues, so im not sure if i should go head and replace it just to be sure. Also just put a new battery in to rule that out as well. Any help would be greatly appreciated! Sorry for the long post, just wanted to give all the details. Here is the video for reference:
SOLVED! HELP! 03 Silverado intermittent Limp Mode
- Thread starter Khughes6103
- Start date
Welcome to GMT Nation...
(1) You can Download the GM OEM Factory Digital Service Manual for your Full Size Truck here:
gmtnation.com
(Courtesy @Mooseman looking out for us all...)
(2) There HAVE been a few cases where the Rubber Seal surrounding the 20 Pin In-Dwelling Connector that pops up from the Inside of the Passenger Side ledge of the 4L60E has failed allowing the ATF to leak into and pool up inside of the lower portion of the 20 Pin Connector.
With the Outer Transmission 20 Pin Harness Plug inserted (Ovoid, Pale Green and ribbed with two Pinch Points for the "Squeeze and Lift" action necessary to Un-Plug it) that harness connector would lose the Electrical Continuity in between the 20 Pin Male to Female Wires-to-Contacts and the B(+) Pink Wire feeding the constant 12+ Volts DC to ALL of those Solenoids. This can cause an intermittent loss of Solenoid Action as a result and unless that ATF is thoroughly and completely cleaned out of both sides of this 20 Pin interface... the problem can return.
If memory serves, for the Trailblazer 4L60E Transmission, the Solution was to remove the Old Solenoid Electrical Harness after dropping the Pan and then cleaning that horizontal through port, followed by inserting that Brand New interior 20 Pin Harness Plug with a NEW Sealing Grommet up through the hole until it clicked solidly in place. After that New Seal was re-affirmed, the Two Connections were plugged firmly together and the 12+ VDC Power was restored with all of the Solenoids worked normally during the 1-2 and 2-3 Shifts thereafter.
This Linked site has a Bunch of 2003 Fuse Panel Images and Identifying Table of Contents (TOC) further down the page for your particular Year-Make-Model Truck:
stickerdeals.net
(1) You can Download the GM OEM Factory Digital Service Manual for your Full Size Truck here:
Full Size Service Manuals
Thanks to our good friend @Reprise , we now have a set for full size trucks. Although these are specifically for 1998-2006 Silverado and Sierra, these will also be useful for Tahoe and Suburban owners. Full Size GM Truck Service Manuals (655.7 MB) NOTE: This is a specific login to download...
gmtnation.com
(Courtesy @Mooseman looking out for us all...)
(2) There HAVE been a few cases where the Rubber Seal surrounding the 20 Pin In-Dwelling Connector that pops up from the Inside of the Passenger Side ledge of the 4L60E has failed allowing the ATF to leak into and pool up inside of the lower portion of the 20 Pin Connector.
With the Outer Transmission 20 Pin Harness Plug inserted (Ovoid, Pale Green and ribbed with two Pinch Points for the "Squeeze and Lift" action necessary to Un-Plug it) that harness connector would lose the Electrical Continuity in between the 20 Pin Male to Female Wires-to-Contacts and the B(+) Pink Wire feeding the constant 12+ Volts DC to ALL of those Solenoids. This can cause an intermittent loss of Solenoid Action as a result and unless that ATF is thoroughly and completely cleaned out of both sides of this 20 Pin interface... the problem can return.
If memory serves, for the Trailblazer 4L60E Transmission, the Solution was to remove the Old Solenoid Electrical Harness after dropping the Pan and then cleaning that horizontal through port, followed by inserting that Brand New interior 20 Pin Harness Plug with a NEW Sealing Grommet up through the hole until it clicked solidly in place. After that New Seal was re-affirmed, the Two Connections were plugged firmly together and the 12+ VDC Power was restored with all of the Solenoids worked normally during the 1-2 and 2-3 Shifts thereafter.
This Linked site has a Bunch of 2003 Fuse Panel Images and Identifying Table of Contents (TOC) further down the page for your particular Year-Make-Model Truck:
stickerdeals.net - stickerdeals Resources and Information.
stickerdeals.net is your first and best source for all of the information you’re looking for. From general topics to more of what you would expect to find here, stickerdeals.net has it all. We hope you find what you are searching for!
stickerdeals.net
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Mooseman
Moderator
Although not the same platform, it's the same transmission and issues. Should give lots of pointers:
Transmission with multiple codes
Another Transmission with Multiple codes
More Multiple Codes
Transmission with multiple codes
Another Transmission with Multiple codes
More Multiple Codes
Thanks guys! I will unplug the 20 pin connector again and see if it has fluid in it again. If so, Can i just flood the connector with contact cleaner and test it to see if that resolves it, and then replace the harness?
Mooseman
Moderator
I noticed earlier when I went outside and unplugged the connector that it did have ATF in it again. I unplugged it and just kind of shook it out and wiped it off with a paper towel plugged it back in and it reset. However this is not the 20 pin connector, this is the 4 pin what looks to be speed sensor at the back of the transmission. Would that make any sense for that to have ATF inside it and be grounding something out?
Mooseman
Moderator
Maybe if it's damaged somehow and allowing fluid past it and into the connector. Definitely not good. Is yours 2WD or 4x4? It shouldn't throw a bunch of codes, maybe just one or two related to the speed sensor only. It could go into a limp mode if it can't sense speed. I once diagnosed a truck like yours that had a transmission replaced but the owner swapped the speed two sensor connectors for the front and rear sensors on the transfer case. No speed on the speedo, not shifting and no codes. Swapped them around and he was back in business.
2wd. My speedometer seems to be working fine. I’m gonna try to look at the 20 pin in the morning. That cat was too hot to get my hand in there earlier.
This is "The Good Stuff" ... Because It is HIGHLY Dialectric, it can actually be sprayed directly into Active Electrical Connections and running Electric Motors without shorting out or burning... so it does NOT have to completely dry out when sprayed into both tiny spaces within both sides of the 20 Pin M-F Connector(s). Please... Wear Eye Protection:
This is an Important Resource of the 185 Page PDF as THE Complete GM 4L60E/65E/70E- 4L80E/85E Transmission Trouble Codes Diagnostics and Hardware Information Service Manual that comes from the ATSG (Automotive Transmission Service Group). Well worth Downloading to your Mechanic's Library:
This is an Important Resource of the 185 Page PDF as THE Complete GM 4L60E/65E/70E- 4L80E/85E Transmission Trouble Codes Diagnostics and Hardware Information Service Manual that comes from the ATSG (Automotive Transmission Service Group). Well worth Downloading to your Mechanic's Library:
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Ok, so this morning I Unpluged the 20 pin connector as well as the speed sensor at the back of the transmission and cleaned them both with contact cleaner and let them dry I did check the 20 pin connector on the E Pin and had 12 V when the switch was on. I plugged everything back in and fired it up and it ran fine. But the next time I cranked it it was back to the same limp mode symptoms.
This is an excerpt from the ATSG Manual that delves deeper into the problem of trying to isolate "Multiple Codes" that may NOT actually be related to a problem with the Transmission Harness or the Solenoids. My thinking now is that the Ignition Switch and its connection to Powering the "E" Circuit with 12 Volts DC via the Pink Wire through the 20 Pin Connector may be involved. This may be the reason why:
“When accessing codes with a scan tool there are times when what you see is not what you get, in other words the code may be misleading or invalid at the time of retrieval. There are various types of codes, some are straight forward and some are not. “Single Circuit” type codes are usually, but not always, straight forward. For example, a code P0753 for a 1-2 shift solenoid circuit, is usually a short or open fault in the solenoid, the solenoids wiring or the computer.
The problem arises when you are dealing with “Multiple Circuit” or “Symptom” codes. Multiple circuit codes can be a problem due to the fact that they may share a common voltage supply or ground, such as TPS, TFT, MAF, etc. The computer is going to check the other sensors in the multiple circuit before a code is stored. This may result in multiple codes due to OBD-II systems not only check for shorts or opens, but also check for “out of range” meaning the value of the faulty sensor(s) does not meet the target value programmed into the vehicle computer. It is now up to the technician to isolate the cause of the problem by using a combination of a scan tool with bi-directional control, a volt meter or an oscilloscope, or a transmission tester, or all of these.
Symptom codes may cause the vehicle to operate improperly in some manner which could be in the form of a drive-ability or a performance issue which could affect the engine and the transmission. What makes these codes more difficult to diagnose is, they can cause system functions to become disabled as a default action which can lead the technician to the wrong area causing a mis-diagnosis. A good example of this would be a solenoid performance code or a component slip code. Mechanical faults are not under the computers control therefore it may not be able to tell you which component is bad. This is due to the computers control system working properly, but, it is trying to compensate for the mechanical problem and will store a code that may be misleading.”
“When accessing codes with a scan tool there are times when what you see is not what you get, in other words the code may be misleading or invalid at the time of retrieval. There are various types of codes, some are straight forward and some are not. “Single Circuit” type codes are usually, but not always, straight forward. For example, a code P0753 for a 1-2 shift solenoid circuit, is usually a short or open fault in the solenoid, the solenoids wiring or the computer.
The problem arises when you are dealing with “Multiple Circuit” or “Symptom” codes. Multiple circuit codes can be a problem due to the fact that they may share a common voltage supply or ground, such as TPS, TFT, MAF, etc. The computer is going to check the other sensors in the multiple circuit before a code is stored. This may result in multiple codes due to OBD-II systems not only check for shorts or opens, but also check for “out of range” meaning the value of the faulty sensor(s) does not meet the target value programmed into the vehicle computer. It is now up to the technician to isolate the cause of the problem by using a combination of a scan tool with bi-directional control, a volt meter or an oscilloscope, or a transmission tester, or all of these.
Symptom codes may cause the vehicle to operate improperly in some manner which could be in the form of a drive-ability or a performance issue which could affect the engine and the transmission. What makes these codes more difficult to diagnose is, they can cause system functions to become disabled as a default action which can lead the technician to the wrong area causing a mis-diagnosis. A good example of this would be a solenoid performance code or a component slip code. Mechanical faults are not under the computers control therefore it may not be able to tell you which component is bad. This is due to the computers control system working properly, but, it is trying to compensate for the mechanical problem and will store a code that may be misleading.”
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Great info, thanks! As cheap as the ignition is, I’ll go ahead and replace it. Anything special is could do other than disconnect the battery?
Yes. If your Switch has been replaced on a prior occasion... make certain to rotate the Ignition Key Counter-Clockwise absolutely as far back as possible BEFORE removing the the Key from the Lock-Work. Before installing the New Switch , you MUST Pre-Align the Nylon Teeth inside to match those of the Old Switch EXACTLY. And Please... Use ONLY the ACDelco flavor of this switch purchased from either NAPA or a GM Dealership. There are numerous, excellent Ignition Switch Threads available on GMT Nation and on Youtube to review for any other anecdotal R&R Help.
There are only Two Kinds of Ignition Switches:
(1) Those that have FAILED.
(2) Those that are going to FAIL.
There are only Two Kinds of Ignition Switches:
(1) Those that have FAILED.
(2) Those that are going to FAIL.
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Well, yesterday was a week since I put in the AC Delco ignition. No issues since. That’s a longest it has gone with no issue. Fingers crossed this has resolve the issue. Thanks everyone for the advice!!!