Wrote this for DF and figured I'd copy it over here too.
I have seen a lot of threads lately about people having broken or stuck ECM pins. Usually this is during a DSP5 installation or High Idle. There is also a lot of half accurate information suggesting how to fix this issue. I've decided to put together a little DIY thread, I hope this helps everybody.
First thing first, I recommend disconnecting the batteries before doing anything electrical, especially with ECM plugs.
You will need to remove the ECM plug from the ECM, remove the pin lock clip, etc..
I'm going to write this with options to try before resorting to the last method which is a little more extreme.
You need to be very patient through this process, if you start to get frustrated you should walk away. Otherwise you'll try to force something and likely cause consequential damage. Trust me, I've been there.
Option 1
Tools: Needle Nose Pliers (I recommend some with smooth surfaces instead of jagged), Sewing Needle (I recommend having a couple spares handy) and a normal sized large safety pin.
To remove an installed or stuck pin, get a sewing needle and a safety clip. Some people recommend paperclips, but I found them to be either too large or more likely to bend.
Remove the plug and when looking at the bottom of the ECM plug, identify which pin you are trying to remove.
You should see the ECM pin hole and a smaller hole next to it. Go ahead and push the sewing needle in the smallest hole. It will slide in, but won't have a LOT of resistance. This is pressing a release level on the terminal pin. I used needle nose pliers to hold the needle and push it in.
Then you will take the safety pin and straighten it out. Push it through the ECM Pin (larger hole) and you should feel the pin pushing out. If the pin is clocked wrong, it may require a little more force. Be careful as you're pushing the pin through, how far the safety pin is in the plug. You should see the pin start coming out the backside, if you don't you may need to pull the safety pin out and re-position it again. You're trying to push on the tip of the ECM terminal.
Once you see 1/4"-1/2" of the terminal coming out the backside, I used needle nose pliers to gently grab it and pull it out the rest of the way.
Option 2
(I had a terminal break and this is the situation to use if the first option is unsuccessful.)
As in Option 1, make sure the battery is disconnected.
Warning: Be attentive to how far the drill bit is in, if it is TOO far, it will cause damage to other pins or wires.
Tools: Drill, a 1/16" drill bit, a 1/16" round punch, and the tools from Option 1.
First, from the bottom flat part of the ECM plug, you will locate the ECM pin you are trying to remove.
Take the drill bit and while keeping the drill bit straight you want to drill into the bottom of the ECM plug just barely. You are only trying to drill into the black plastic to enlarge that part of the hole, you DO NOT want to make contact with the metal terminal itself. This hole should be 1/18" deep or less.
Once the hole is made, it will likely be large enough that it makes it impossible to stick the sewing needle in the release hole. If it hasn't, go ahead and stick the needle in. If you don't have a hole remaining, don't worry about it. More then likely this terminal pin is clocked wrong or not clicked in if you are having this severe of an issue.
Take the 1/16" punch (smallest one I could find at Sears) and push it through the new hole in the bottom of the ECM plug. You will be applying some force, but just do this with your hand. DO NOT try to use a hammer or anything, it's not necessary and is likely to cause damage.
With a little force you will be able to push the pin out. Again, wait until the pin is coming out the top approx 1/4" and then gently remove the terminal with needle nose pliers. This is to ensure you don't cause further damage to the terminal and make it even harder to get the pin out.
During this entire process, be careful not to cause any damage to the wires on the ECM plug.
Once the terminal has been removed, I took the 1/16" drill bit and fed it through the track starting on the wire side pushing it to the flat side. I completed this process a few times. This helped clean out any debris in the track. Do NOT feed this through from the bottom, as it is pushing the debris into the track and can potentially cause damage to the other wires on the ECM!
Reseat Pin
Once the pin is removed, track is cleaned, you can re-seat the pin. It is IMPERATIVE that you take your time and ensure the pin is clocked correctly. Due to the removal process you are likely to have some issues seating the pin, but it should slide in smoothly. All challenges will be in the last little bit. If the terminal pin isn't sliding in smoothly, then you should remove it and try again verifying it's clocked correctly.
Once the pin is slid in completely and clocked correctly, you can use the safety pin to push from the back side (wire side) to seat the pin completely. It may NOT click like normal, but on the flat side of the plug you should see the end of the terminal but up against the remaining black plastic.
Slide your pin lock back on and it should slide in smoothly. If it stops, it means the terminal pin is not seated completely and needs to be pushed down further.
Damaged Pins
If you determine of your pins are damaged and not usable you have a few different options.
If you use a method that involves connecting two pieces of wire, I highly recommend using a solder connection and heat shrink to ensure a clean and complete connection
Option 1
Purchase a new pin already crimped onto a wire, you can buy them from a number of online vendors. I personally would recommend giving Rob at ATPTrucks.com at a call and he can get you taken care of.
Option 2 (Not a recommended option)
Purchase a new terminal pin from the GM dealer, this is a challenge. The parts guy is not going to know what you are talking about. If you search this forum and other Duramax forums you can figure out the bin and drawer number the pin is located in. Even with this information, the parts guy is probably going to not know what you're talking about and it will require quite a bit of conversation and questions to get the right pin.
Once you have bought the pin, you will have to find a way to crimp the pin. I understand there is a special tool, but I have no idea where you can buy it. If you can buy, I understand it is over $400. I personally found that if you're creative you can use some other tools, but you need to make sure the wire will not pull out. To accomplish this, I recommend using some solder to complete the connection and keep the terminal pin and wire securely attached. This requires some fine soldering ability, because the size of this crimp / solder must be small enough the pin can fit into the track without issues.
Option 3
If you are installing a DSP5 switch, you technically do NOT need to ground the switch at the ECM. The ECM ground is preferred, but you can cut that terminal pin and wire off and attach it to the signal wire. Then you can take and ground the DSP5 switch under the dash.
If you select this option, you should connect with a v2 and data log DSP switch position and voltage to ensure that the switch is switching through all tunes correctly. If you have any issues, send that data log to your tuner and he should be able to make the necessary adjustments to your tune.
I hope this tutorial is useful, please feel free to message me if you have any questions, find spelling / grammatical errors, or think I should make any revisions. This isn't perfect, but I'm just trying to put useful information on the forum
There are other methods on the forum that I do not recommend. This includes trying to drill out the entire terminal pin. This will leave debris in the track and prove unsuccessful.
I have seen a lot of threads lately about people having broken or stuck ECM pins. Usually this is during a DSP5 installation or High Idle. There is also a lot of half accurate information suggesting how to fix this issue. I've decided to put together a little DIY thread, I hope this helps everybody.
First thing first, I recommend disconnecting the batteries before doing anything electrical, especially with ECM plugs.
You will need to remove the ECM plug from the ECM, remove the pin lock clip, etc..
I'm going to write this with options to try before resorting to the last method which is a little more extreme.
You need to be very patient through this process, if you start to get frustrated you should walk away. Otherwise you'll try to force something and likely cause consequential damage. Trust me, I've been there.
Option 1
Tools: Needle Nose Pliers (I recommend some with smooth surfaces instead of jagged), Sewing Needle (I recommend having a couple spares handy) and a normal sized large safety pin.
To remove an installed or stuck pin, get a sewing needle and a safety clip. Some people recommend paperclips, but I found them to be either too large or more likely to bend.
Remove the plug and when looking at the bottom of the ECM plug, identify which pin you are trying to remove.
You should see the ECM pin hole and a smaller hole next to it. Go ahead and push the sewing needle in the smallest hole. It will slide in, but won't have a LOT of resistance. This is pressing a release level on the terminal pin. I used needle nose pliers to hold the needle and push it in.
Then you will take the safety pin and straighten it out. Push it through the ECM Pin (larger hole) and you should feel the pin pushing out. If the pin is clocked wrong, it may require a little more force. Be careful as you're pushing the pin through, how far the safety pin is in the plug. You should see the pin start coming out the backside, if you don't you may need to pull the safety pin out and re-position it again. You're trying to push on the tip of the ECM terminal.
Once you see 1/4"-1/2" of the terminal coming out the backside, I used needle nose pliers to gently grab it and pull it out the rest of the way.
Option 2
(I had a terminal break and this is the situation to use if the first option is unsuccessful.)
As in Option 1, make sure the battery is disconnected.
Warning: Be attentive to how far the drill bit is in, if it is TOO far, it will cause damage to other pins or wires.
Tools: Drill, a 1/16" drill bit, a 1/16" round punch, and the tools from Option 1.
First, from the bottom flat part of the ECM plug, you will locate the ECM pin you are trying to remove.
Take the drill bit and while keeping the drill bit straight you want to drill into the bottom of the ECM plug just barely. You are only trying to drill into the black plastic to enlarge that part of the hole, you DO NOT want to make contact with the metal terminal itself. This hole should be 1/18" deep or less.
Once the hole is made, it will likely be large enough that it makes it impossible to stick the sewing needle in the release hole. If it hasn't, go ahead and stick the needle in. If you don't have a hole remaining, don't worry about it. More then likely this terminal pin is clocked wrong or not clicked in if you are having this severe of an issue.
Take the 1/16" punch (smallest one I could find at Sears) and push it through the new hole in the bottom of the ECM plug. You will be applying some force, but just do this with your hand. DO NOT try to use a hammer or anything, it's not necessary and is likely to cause damage.
With a little force you will be able to push the pin out. Again, wait until the pin is coming out the top approx 1/4" and then gently remove the terminal with needle nose pliers. This is to ensure you don't cause further damage to the terminal and make it even harder to get the pin out.
During this entire process, be careful not to cause any damage to the wires on the ECM plug.
Once the terminal has been removed, I took the 1/16" drill bit and fed it through the track starting on the wire side pushing it to the flat side. I completed this process a few times. This helped clean out any debris in the track. Do NOT feed this through from the bottom, as it is pushing the debris into the track and can potentially cause damage to the other wires on the ECM!
Reseat Pin
Once the pin is removed, track is cleaned, you can re-seat the pin. It is IMPERATIVE that you take your time and ensure the pin is clocked correctly. Due to the removal process you are likely to have some issues seating the pin, but it should slide in smoothly. All challenges will be in the last little bit. If the terminal pin isn't sliding in smoothly, then you should remove it and try again verifying it's clocked correctly.
Once the pin is slid in completely and clocked correctly, you can use the safety pin to push from the back side (wire side) to seat the pin completely. It may NOT click like normal, but on the flat side of the plug you should see the end of the terminal but up against the remaining black plastic.
Slide your pin lock back on and it should slide in smoothly. If it stops, it means the terminal pin is not seated completely and needs to be pushed down further.
Damaged Pins
If you determine of your pins are damaged and not usable you have a few different options.
If you use a method that involves connecting two pieces of wire, I highly recommend using a solder connection and heat shrink to ensure a clean and complete connection
Option 1
Purchase a new pin already crimped onto a wire, you can buy them from a number of online vendors. I personally would recommend giving Rob at ATPTrucks.com at a call and he can get you taken care of.
Option 2 (Not a recommended option)
Purchase a new terminal pin from the GM dealer, this is a challenge. The parts guy is not going to know what you are talking about. If you search this forum and other Duramax forums you can figure out the bin and drawer number the pin is located in. Even with this information, the parts guy is probably going to not know what you're talking about and it will require quite a bit of conversation and questions to get the right pin.
Once you have bought the pin, you will have to find a way to crimp the pin. I understand there is a special tool, but I have no idea where you can buy it. If you can buy, I understand it is over $400. I personally found that if you're creative you can use some other tools, but you need to make sure the wire will not pull out. To accomplish this, I recommend using some solder to complete the connection and keep the terminal pin and wire securely attached. This requires some fine soldering ability, because the size of this crimp / solder must be small enough the pin can fit into the track without issues.
Option 3
If you are installing a DSP5 switch, you technically do NOT need to ground the switch at the ECM. The ECM ground is preferred, but you can cut that terminal pin and wire off and attach it to the signal wire. Then you can take and ground the DSP5 switch under the dash.
If you select this option, you should connect with a v2 and data log DSP switch position and voltage to ensure that the switch is switching through all tunes correctly. If you have any issues, send that data log to your tuner and he should be able to make the necessary adjustments to your tune.
I hope this tutorial is useful, please feel free to message me if you have any questions, find spelling / grammatical errors, or think I should make any revisions. This isn't perfect, but I'm just trying to put useful information on the forum
There are other methods on the forum that I do not recommend. This includes trying to drill out the entire terminal pin. This will leave debris in the track and prove unsuccessful.