mghoodlum
Well-Known Member
- First Name
- Matt
- Joined
- Oct 24, 2019
- Threads
- 3
- Messages
- 87
- Reaction score
- 51
- Location
- Midland, TX
- Vehicle(s)
- JT Pearl Blue Rubicon on order
- Thread starter
- #1
I bought a used Magnuson SC off Facebook for about half of new. It came off a one year old gladiator and included the PCM the previous owner used. The previous owner took the SC off when he sold the vehicle. He had replaced the PCM instead of unlocking it when new.
First Lesson: It is not very easy of not impossible to change the VIN in the PCM.
I reached out to HP Tuners who unlocks the PCMs for our trucks. This is the feedback I received. “
“When using a PCM from a donor PCM it does need to have a compatible part number to your vehicle. If it is from the same year/make/model it would not be an issue. The PCM would need to be programmed with your vehicle VIN/OS information. This can be done with a Dodge witech or j2534 tool. “
so I paid $200 extra for the unlocked PCM
After looking for independent shops locally that could changed The VIN unsuccessful I took it to a local Jeep Dealer and told them what I needed done. Before accepting the service they warned me it would be $250 and there was no guarantee that they would be able to perform it. After speaking with HP Tuners I was confident it would not be a problem so I went ahead with the work.
After waiting A bit the tech asked to speak with me. He called me back and showed me his Wi-Tech was showing him and what was happening. He also loaned a Snap-On tool from another tech. Long story short in either one he could not change the VIN.
As he reinstalled the PCM he was being very gentle with it and working it very slowly. I asked him why he was doing it this way and he said they are known to break easily and are difficult to fix. This seems like unneeded info but if you keep reading you will see why it is an important part of the story.
After this I continued to search for another shop who might know how to do this. I even reached back out to HP Tuners for additional help. Besides telling me it was possible, they could or would not offer any other assistance.
I was afraid of wasting yet more money and decided to send my PCM in to be unlocked.
The connector for the PCM wiring harness is fragile and not a serviceable part (per Mopar)
I was leaving town for a short vacation so I decided to remove my PCM and have it sent off. When I was removing it I realized that the locking mechanism on the PCM harness was broken and would not allow the plates to slide off so the harness could be removed. Since it was broken I decided to break it further until I could remove the harness and replace the end. I went to my favorite online Mopar parts supplier and found that I could not order the connector. I ended up finding one on a site for an auto industry parts supplier. It was on my door step before I arrived home. When my PCM arrived I put it on with the broken connector and installed my required security bypass cable. I took it for a test drive and discovered I was having many error flash across the informant screen. I thought it might be because my PCM wasn’t making good connection. It’s also possible this was a bad HP Tuners Smart Cable as I had similar behavior when I tried to upload a tune later.
I wanted to find a wiring diagram for this engine harness but since Jeep doesn’t consider it a serviceable part they do not provide a diagram for the entire harness. In order to not mess anything up I decided I could do this by just unplugging and repositioning each wire one at a time.
The connector is a 96 pin connector. I had to make a tool to release each pin from the connector and I painstaking removed each pin and installed it in the new connector. One at a time. As I moved forward I sometimes had to remove a row of 4 wires at a time. There were also some pin holes that were unused and it made it difficult to keep straight. My first test drive proved that I did not do this correctly as it ran poorly and I had numerous warning light come on. I then parked it in the drive. The next time I went to start the truck the battery was dead as well. I figured it was a result of the bad wiring job so I unplugged the PCM and put a charger on the battery. I then searched for a diagram but ultimately figured that if MOPAR thought it was better to change the harness rather than service it that may be the route I should go. So started removing the harness. The work was slow and when I broke one of the connected sensors thought it might be time to get some help from a pro. I ended up having it towed in. When it arrived they couldn’t get itout of park. Likely due to the PCM being disconnected so they plugged it in. The shop later called me to tell me they felt like my newly unlocked PCM was fried. I didn’t understand why until they told me they plugged it back in to try to get it out of park. The owner and lead mechanic also told me it would be a couple weeks before he could get to it because this type of work was difficult and he wanted to be around for support and he would be out of town. I order a new PCM in the meantime. When reinstalling the PCM it had to be programmed and a special security key from Jeep had to be entered. The shop sent me to the dealer to get this and I paid $50 for the key. I took it back and the key would not work. The shop was utilizing the official WiTech tool and software. I called and got a replacement key but that would not work either. I got a call from the shop that stated that the key network was different for independent shops and they had to get one through a different channel. So after a month and about $1500 more dollars my truck was back to stock and running.
Lesson 3: Magnuson does not sell individual hoses. Hoses are sold in a kit.
Since I received a used kit (it stated everything included). I realized I was short a hose. I contacted Magnuson who referred me to superchargerwho handles all part orders on their behalf to see about getting a replacement hose. I found out they didn’t sell single hoses and I needed the kit. Upon installation I figured out why. Some of the factory hoses and connectors are used and if you uninstall it you would have to replace the factory hoses that were cut or could reuse the Magnuson hoses as well. As it turned out I had to us 2 of these hoses. It might be a good idea to have these hoses as it took me 3 weeks to receive the hoses. Also if you buy a used kit you will likely need this kit.
Now it seemed as I had everything I was about ready to install the SC but I still needed an unlocked PCM since the last one was fried. I sent my brand new PCM in to get unlocked and start over hopefully smarter.
I planned to use Dave’s tune so I wasn’t worried about not having the Magnuson tune. Being I had so much trouble I also reached out to Dave to try out his naturally aspirated tune before trying out the supercharger.
This allowed me to get a bit more familiar with the flashing and such as well. This tune was smoother and worked better than stock. This gave me the confidence to take on the install.
The first step was to send a copy of my factory program to Dave. I ran into an issue here as well. When I tried to connect I had many issues. I decided to remove my HP Tuners Smart Cable and replace it with my Autel bypass cable. This worked. I also had a small issue where the controller type wasn’t recognized and I had to try and pick it from a list.
I was also doing this in my drive way and I believe since my internet connection was poor it led to some failed flashes as it says an internet connection is required and I think it was poor enough that it was giving problems. Once I connected to my phone I quit having the read failures.
Bonus lesson: Crank Cam Resync
When I installed Dave’s NA tune it ran very rough. I was told to do a crank cam resync. This was unavailable in the latest beta and I had to reach out to HP Tuners and get a new version where they added this feature for my build. Once I completed this it ran smooth as butter!
The install was pretty straight forward with the biggest challenges being mounting the intercooler pump on aftermarket fender liners and I also found out I was missing an extension harness and ended up splicing and soldering two wires. I took it very slow reading every instruction until I understood it well. I also did all the “upgrades” in the crib notes section.
It now came time to install the new tune and test drive. Upon starting I knew things didn’t seem right. After test driving check engine light came on throwing rich fueling codes. It also would not make power and would cut out when trying to accelerate. I found that the IAT was running very high as well and suspected an issue with the pump. While the truck would get down the road things didn’t seem right. I reached out to @DAVECS1 and the first order of business is to determine why IAT was so high. This lead to
Lesson 4: The intercooler pump (best know as Varimax Pump) shuts off when not moving fluid.
I suspects the issue was with my pump. I checked for voltage from battery to electrical connector that connects to pump and it all read 14v. I could figure out why the pump would run. The pump is smart and can be controlled in different ways and is variable speed however in this application it is wired without the control wires and should operate as either on or off. The pump is wired to the injector fuse so if the truck is running the pump should be running. I could get it to come on but it would shut off. I wired the pump up on the bench and the pump would come on for a few seconds and turn off. I called superchargerparts.con and they weee out of stock. I found a pump on eBay and had it over nighted. When I put it in the truck it came on for a second and I cheered before it quickly turned off. At this point I knew it wasn’t the pump and suspected it had a protection feature to keep it from running dry. I had thought this was a possibility before but since there was fluid on both sides of the pump when I removed the pump I discounted this. I also wanted to rule out a problem with the relay so I jumped the relay (after a few google lessons) and noticed the pump would come on and off. I mailed the hose to prime the pump and after about a half dozen attempts the pump came on and ran. I logged and IAT came down as expected but the truck still would not make power. I updated Dave and he had concerns about my intake Cam on the drivers side. To learn more about this read the thread “the good and bad of roots supercharger”. In short it looks like the intake cam is likely shot. The major evidence of this is misfires on only cylinders 1,3, and 5 when revving engine above 4000rpm. I’ve also found if I keep the RPM low it seems to drive fairly normal. What is strange is this problem was not evident on factory tuning or even Dave’s Naturally aspirated tune. It only showed up under forced air. https://www.jeepgladiatorforum.com/forum/threads/the-good-and-the-bad-of-a-roots-supercharger.54832/
I have now ordered the suggested parts on that page (which are about $700 total, but I couldn’t get the CAM phaser or one of the solenoids, also the lash adjusters are very hard to found but after some work I found them). I am waiting in the parts now and plan to install them myself.
It seems I have had about every problem possible so I’m not certain this will fix the issue but I am hopeful and I have learned so much about how these engines run and the systems that govern them.
I figured I would start writing this up as much of this information I could not find on the internet anywhere (and I searched most of it). If you ever need some assistance PM me and hopefully I can save you a few hours and dollars.
First Lesson: It is not very easy of not impossible to change the VIN in the PCM.
I reached out to HP Tuners who unlocks the PCMs for our trucks. This is the feedback I received. “
“When using a PCM from a donor PCM it does need to have a compatible part number to your vehicle. If it is from the same year/make/model it would not be an issue. The PCM would need to be programmed with your vehicle VIN/OS information. This can be done with a Dodge witech or j2534 tool. “
so I paid $200 extra for the unlocked PCM
After looking for independent shops locally that could changed The VIN unsuccessful I took it to a local Jeep Dealer and told them what I needed done. Before accepting the service they warned me it would be $250 and there was no guarantee that they would be able to perform it. After speaking with HP Tuners I was confident it would not be a problem so I went ahead with the work.
After waiting A bit the tech asked to speak with me. He called me back and showed me his Wi-Tech was showing him and what was happening. He also loaned a Snap-On tool from another tech. Long story short in either one he could not change the VIN.
As he reinstalled the PCM he was being very gentle with it and working it very slowly. I asked him why he was doing it this way and he said they are known to break easily and are difficult to fix. This seems like unneeded info but if you keep reading you will see why it is an important part of the story.
After this I continued to search for another shop who might know how to do this. I even reached back out to HP Tuners for additional help. Besides telling me it was possible, they could or would not offer any other assistance.
I was afraid of wasting yet more money and decided to send my PCM in to be unlocked.
The connector for the PCM wiring harness is fragile and not a serviceable part (per Mopar)
I was leaving town for a short vacation so I decided to remove my PCM and have it sent off. When I was removing it I realized that the locking mechanism on the PCM harness was broken and would not allow the plates to slide off so the harness could be removed. Since it was broken I decided to break it further until I could remove the harness and replace the end. I went to my favorite online Mopar parts supplier and found that I could not order the connector. I ended up finding one on a site for an auto industry parts supplier. It was on my door step before I arrived home. When my PCM arrived I put it on with the broken connector and installed my required security bypass cable. I took it for a test drive and discovered I was having many error flash across the informant screen. I thought it might be because my PCM wasn’t making good connection. It’s also possible this was a bad HP Tuners Smart Cable as I had similar behavior when I tried to upload a tune later.
I wanted to find a wiring diagram for this engine harness but since Jeep doesn’t consider it a serviceable part they do not provide a diagram for the entire harness. In order to not mess anything up I decided I could do this by just unplugging and repositioning each wire one at a time.
The connector is a 96 pin connector. I had to make a tool to release each pin from the connector and I painstaking removed each pin and installed it in the new connector. One at a time. As I moved forward I sometimes had to remove a row of 4 wires at a time. There were also some pin holes that were unused and it made it difficult to keep straight. My first test drive proved that I did not do this correctly as it ran poorly and I had numerous warning light come on. I then parked it in the drive. The next time I went to start the truck the battery was dead as well. I figured it was a result of the bad wiring job so I unplugged the PCM and put a charger on the battery. I then searched for a diagram but ultimately figured that if MOPAR thought it was better to change the harness rather than service it that may be the route I should go. So started removing the harness. The work was slow and when I broke one of the connected sensors thought it might be time to get some help from a pro. I ended up having it towed in. When it arrived they couldn’t get itout of park. Likely due to the PCM being disconnected so they plugged it in. The shop later called me to tell me they felt like my newly unlocked PCM was fried. I didn’t understand why until they told me they plugged it back in to try to get it out of park. The owner and lead mechanic also told me it would be a couple weeks before he could get to it because this type of work was difficult and he wanted to be around for support and he would be out of town. I order a new PCM in the meantime. When reinstalling the PCM it had to be programmed and a special security key from Jeep had to be entered. The shop sent me to the dealer to get this and I paid $50 for the key. I took it back and the key would not work. The shop was utilizing the official WiTech tool and software. I called and got a replacement key but that would not work either. I got a call from the shop that stated that the key network was different for independent shops and they had to get one through a different channel. So after a month and about $1500 more dollars my truck was back to stock and running.
Lesson 3: Magnuson does not sell individual hoses. Hoses are sold in a kit.
Since I received a used kit (it stated everything included). I realized I was short a hose. I contacted Magnuson who referred me to superchargerwho handles all part orders on their behalf to see about getting a replacement hose. I found out they didn’t sell single hoses and I needed the kit. Upon installation I figured out why. Some of the factory hoses and connectors are used and if you uninstall it you would have to replace the factory hoses that were cut or could reuse the Magnuson hoses as well. As it turned out I had to us 2 of these hoses. It might be a good idea to have these hoses as it took me 3 weeks to receive the hoses. Also if you buy a used kit you will likely need this kit.
Now it seemed as I had everything I was about ready to install the SC but I still needed an unlocked PCM since the last one was fried. I sent my brand new PCM in to get unlocked and start over hopefully smarter.
I planned to use Dave’s tune so I wasn’t worried about not having the Magnuson tune. Being I had so much trouble I also reached out to Dave to try out his naturally aspirated tune before trying out the supercharger.
This allowed me to get a bit more familiar with the flashing and such as well. This tune was smoother and worked better than stock. This gave me the confidence to take on the install.
The first step was to send a copy of my factory program to Dave. I ran into an issue here as well. When I tried to connect I had many issues. I decided to remove my HP Tuners Smart Cable and replace it with my Autel bypass cable. This worked. I also had a small issue where the controller type wasn’t recognized and I had to try and pick it from a list.
I was also doing this in my drive way and I believe since my internet connection was poor it led to some failed flashes as it says an internet connection is required and I think it was poor enough that it was giving problems. Once I connected to my phone I quit having the read failures.
Bonus lesson: Crank Cam Resync
When I installed Dave’s NA tune it ran very rough. I was told to do a crank cam resync. This was unavailable in the latest beta and I had to reach out to HP Tuners and get a new version where they added this feature for my build. Once I completed this it ran smooth as butter!
The install was pretty straight forward with the biggest challenges being mounting the intercooler pump on aftermarket fender liners and I also found out I was missing an extension harness and ended up splicing and soldering two wires. I took it very slow reading every instruction until I understood it well. I also did all the “upgrades” in the crib notes section.
It now came time to install the new tune and test drive. Upon starting I knew things didn’t seem right. After test driving check engine light came on throwing rich fueling codes. It also would not make power and would cut out when trying to accelerate. I found that the IAT was running very high as well and suspected an issue with the pump. While the truck would get down the road things didn’t seem right. I reached out to @DAVECS1 and the first order of business is to determine why IAT was so high. This lead to
Lesson 4: The intercooler pump (best know as Varimax Pump) shuts off when not moving fluid.
I suspects the issue was with my pump. I checked for voltage from battery to electrical connector that connects to pump and it all read 14v. I could figure out why the pump would run. The pump is smart and can be controlled in different ways and is variable speed however in this application it is wired without the control wires and should operate as either on or off. The pump is wired to the injector fuse so if the truck is running the pump should be running. I could get it to come on but it would shut off. I wired the pump up on the bench and the pump would come on for a few seconds and turn off. I called superchargerparts.con and they weee out of stock. I found a pump on eBay and had it over nighted. When I put it in the truck it came on for a second and I cheered before it quickly turned off. At this point I knew it wasn’t the pump and suspected it had a protection feature to keep it from running dry. I had thought this was a possibility before but since there was fluid on both sides of the pump when I removed the pump I discounted this. I also wanted to rule out a problem with the relay so I jumped the relay (after a few google lessons) and noticed the pump would come on and off. I mailed the hose to prime the pump and after about a half dozen attempts the pump came on and ran. I logged and IAT came down as expected but the truck still would not make power. I updated Dave and he had concerns about my intake Cam on the drivers side. To learn more about this read the thread “the good and bad of roots supercharger”. In short it looks like the intake cam is likely shot. The major evidence of this is misfires on only cylinders 1,3, and 5 when revving engine above 4000rpm. I’ve also found if I keep the RPM low it seems to drive fairly normal. What is strange is this problem was not evident on factory tuning or even Dave’s Naturally aspirated tune. It only showed up under forced air. https://www.jeepgladiatorforum.com/forum/threads/the-good-and-the-bad-of-a-roots-supercharger.54832/
I have now ordered the suggested parts on that page (which are about $700 total, but I couldn’t get the CAM phaser or one of the solenoids, also the lash adjusters are very hard to found but after some work I found them). I am waiting in the parts now and plan to install them myself.
It seems I have had about every problem possible so I’m not certain this will fix the issue but I am hopeful and I have learned so much about how these engines run and the systems that govern them.
I figured I would start writing this up as much of this information I could not find on the internet anywhere (and I searched most of it). If you ever need some assistance PM me and hopefully I can save you a few hours and dollars.
Sponsored
Last edited:
