C5 Corvette Auto A4 4L60e to Manual M12 T56 Swap Conversion & Write-up
Instructor
Joined: Sep 2016
Posts: 233
Likes: 59
From: Bowling Green, Ky
what exactly in the tune? My best guess why mine doesn't work is the wiring pinout at the pcm might be different year by year. for which pins use cruise. Mine was flashed as either an 02 or 03 manual in hptuners (i cant remember) & my trans harness is 03. Car i 01
Racer
Joined: May 2019
Posts: 316
Likes: 21
From: Michigan
I have a 2002 C5 that I did a manual swap in. From the upper clutch switch (do you have this? I did not know I needed it at first), you can tag the pink wire from the brake switch, so Pink to Pink. The Grey wire from the upper clutch switch, I went to the Blue connector at the PCM. You need terminal 35. Make sure to get the correct pin for this to ensure good connection. I do not know if they are different in wiring locations, but I did not see a different diagram for this in the shop manuals for our cars. The tune put in is for a 2002 manual C5 vette. I can send you a copy of the tune that worked if you like, but I do not warranty or guarantee anything if you put in in your car. The tune is a HP Tuners file. You could have your tuner compare the files first to be sure and safe. In HPT you can do a side by side comparison before you write.
Have you checked the adjustment in the brake and upper clutch switches yet? This could possibly be an easy fix for you. Many others found it to work for them.
Have you checked the adjustment in the brake and upper clutch switches yet? This could possibly be an easy fix for you. Many others found it to work for them.
Instructor
Joined: Sep 2016
Posts: 233
Likes: 59
From: Bowling Green, Ky
I have a 2002 C5 that I did a manual swap in. From the upper clutch switch (do you have this? I did not know I needed it at first), you can tag the pink wire from the brake switch, so Pink to Pink. The Grey wire from the upper clutch switch, I went to the Blue connector at the PCM. You need terminal 35. Make sure to get the correct pin for this to ensure good connection. I do not know if they are different in wiring locations, but I did not see a different diagram for this in the shop manuals for our cars. The tune put in is for a 2002 manual C5 vette. I can send you a copy of the tune that worked if you like, but I do not warranty or guarantee anything if you put in in your car. The tune is a HP Tuners file. You could have your tuner compare the files first to be sure and safe. In HPT you can do a side by side comparison before you write.
Have you checked the adjustment in the brake and upper clutch switches yet? This could possibly be an easy fix for you. Many others found it to work for them.
Have you checked the adjustment in the brake and upper clutch switches yet? This could possibly be an easy fix for you. Many others found it to work for them.
Racer
Joined: May 2019
Posts: 316
Likes: 21
From: Michigan
I think for some reason it varies from either car to car, or year to year. I followed his instructions to a "T". Not all the information needed is there, but, there is a lot of information there. He did a great job at putting the information together and I really do appreciate it. Unless you write instruction for a living, chances are you will miss something. Even the shop manuals for our cars have a 15% chance of errors.
I am only giving information on what worked for me. It may or may not work for the next person. The information is there for options for the next person to try.
I am only giving information on what worked for me. It may or may not work for the next person. The information is there for options for the next person to try.
Intermediate
Joined: Jun 2023
Posts: 26
Likes: 3
Any updates? Looking to accomplish a similar task.
I ask because I could only find decent A4’s in my area and would like to convert it to manual as well.
If preferred, you’re welcome to PM me instead. Thank you!
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Thread Starter
Heel & Toe
Joined: Sep 2018
Posts: 16
Likes: 26
From: Mobile
UPDATE ON "MAIL ORDER TUNING:" Do not useTUNEDBYFROST.
Hi,
In the post, I mention I used Tuned by Frost for the conversion tuning. DO NOT USE HIM ANYMORE. I recently started building my, new to me, WS6. I sent him the ECM & Paypal payment--over a month later, zero replies, he still has my ECM, and PayPal, after a long dispute, refunded me the payment for the tune. I have heard a lot of rumors, both on here, LS1tech, GTO forum, etc (rumors ranging anywhere from drugs, to health issues, to just being a crook). Regardless, whatever is going on, I can tell you that he is no longer in business, yet is keeping his PayPal/site active, with no warnings of this, & is still accepting ECMs with zero plan to return them back to owners. I would encourage you to look at his reviews (EFI Performance: both on Google & Facebook). I had used him four previous times with no issues whatsoever.
I ended up going with Michigan Motorsports (as I needed to purchase a new ecm anyways...), while a bit more expensive, their turn around time is extremely fast. I hope this helps & serves as a warning to others.
Thanks,
John
Hi,
In the post, I mention I used Tuned by Frost for the conversion tuning. DO NOT USE HIM ANYMORE. I recently started building my, new to me, WS6. I sent him the ECM & Paypal payment--over a month later, zero replies, he still has my ECM, and PayPal, after a long dispute, refunded me the payment for the tune. I have heard a lot of rumors, both on here, LS1tech, GTO forum, etc (rumors ranging anywhere from drugs, to health issues, to just being a crook). Regardless, whatever is going on, I can tell you that he is no longer in business, yet is keeping his PayPal/site active, with no warnings of this, & is still accepting ECMs with zero plan to return them back to owners. I would encourage you to look at his reviews (EFI Performance: both on Google & Facebook). I had used him four previous times with no issues whatsoever.
I ended up going with Michigan Motorsports (as I needed to purchase a new ecm anyways...), while a bit more expensive, their turn around time is extremely fast. I hope this helps & serves as a warning to others.
Thanks,
John
Intermediate
Joined: Jun 2023
Posts: 26
Likes: 3
Hey C5 World, need some assistance.
I appreciate all the advice, I replaced the rear main seal and cover with the C&S upgraded cover. I finally had time to remove and install my wiring harness. Looking at your notes from the forum. I didn’t see anything about none of the connectors being left uninstalled.
[img]blob:https://www.corvetteforum.com/dba05d69-e7b7-4657-b1b7-23d45e0d1f68[/img][img]blob:https://www.corvetteforum.com/1d24b8a8-e2c1-4921-94f9-f66dfeedfcdc[/img]
I am unable to connect this one to anything. I’m beginning to wonder if I ordered or was shipped the wrong harness?
Also, this harness has some purple connectors with the small light blues for the front subframe. Is this for magnetic ride?(which I don’t have l)
[img]blob:https://www.corvetteforum.com/c1b648cf-15b7-474e-8f70-88aa86055814[/img][img]blob:https://www.corvetteforum.com/b62966ac-49b0-49c2-a1a7-7b14d5acacf7[/img]
Here’s the harness I got from eBay. https://www.ebay.com/itm/255938117137
I appreciate your feedback.
I appreciate all the advice, I replaced the rear main seal and cover with the C&S upgraded cover. I finally had time to remove and install my wiring harness. Looking at your notes from the forum. I didn’t see anything about none of the connectors being left uninstalled.
[img]blob:https://www.corvetteforum.com/dba05d69-e7b7-4657-b1b7-23d45e0d1f68[/img][img]blob:https://www.corvetteforum.com/1d24b8a8-e2c1-4921-94f9-f66dfeedfcdc[/img]
I am unable to connect this one to anything. I’m beginning to wonder if I ordered or was shipped the wrong harness?
Also, this harness has some purple connectors with the small light blues for the front subframe. Is this for magnetic ride?(which I don’t have l)
[img]blob:https://www.corvetteforum.com/c1b648cf-15b7-474e-8f70-88aa86055814[/img][img]blob:https://www.corvetteforum.com/b62966ac-49b0-49c2-a1a7-7b14d5acacf7[/img]
Here’s the harness I got from eBay. https://www.ebay.com/itm/255938117137
I appreciate your feedback.
Intermediate
Joined: Jun 2023
Posts: 26
Likes: 3
Intermediate
Joined: Jun 2023
Posts: 26
Likes: 3
I’ve just completed the swap myself. However, the car cranks but won’t start. When I turn the key, I hear the fuel pump. But the car just cranks… I believe the battery is fine I have about 12.5 volts.
did you run into any issues where the car would not start?
I’ll double check all of my grounds next.
I have only the drive train in to check if the car runs because I don’t want to pull it all out again haha if I need to make some fixes or changes.
did you run into any issues where the car would not start?
I’ll double check all of my grounds next.
I have only the drive train in to check if the car runs because I don’t want to pull it all out again haha if I need to make some fixes or changes.
I just completed this swap using this writeup as a guide. I’m yet to take it to the tuner, but I will say everything seems to be functioning as advertised. I need to check the reverse lockout as shifting into reverse is pretty stiff, and I haven’t tried the cruise yet, but all in all, this writeup is spot on and helped me a ton.
Thread Starter
Heel & Toe
Joined: Sep 2018
Posts: 16
Likes: 26
From: Mobile
Hi,
Did you do the "does it start?" plug test that I mentioned in my main post?
To answer your question above, you will likely have a plug that does not attach to anything (on my 2002, it was a circular plug). It is hard to tell from your photos, but are you sure you purchased a harness from the same year Corvette? I mentioned the differences, that I know of, in the main post. Also, if you removed your coil packs, verify you remembered to plug them back in. I have seen this missed often when people install longtubes. Keep me updated with what you find out!
-John
Did you do the "does it start?" plug test that I mentioned in my main post?
To answer your question above, you will likely have a plug that does not attach to anything (on my 2002, it was a circular plug). It is hard to tell from your photos, but are you sure you purchased a harness from the same year Corvette? I mentioned the differences, that I know of, in the main post. Also, if you removed your coil packs, verify you remembered to plug them back in. I have seen this missed often when people install longtubes. Keep me updated with what you find out!
-John
Intermediate
Joined: Jun 2023
Posts: 26
Likes: 3
yes, I did the “does it start” test. I removed and cut the yellow and purple wires and installed them in the manual harness as advised. However, I did install a fuse inline with the purple and yellow wires for the “does it start”. I may have to remove it and then test again. But the car just keeps cranking
I have a 2004 Base and purchased a 2004 Z06 manual harness (didn’t think it would matter if it was from a Z06)
I didn’t remove any coil packs.
I have a 2004 Base and purchased a 2004 Z06 manual harness (didn’t think it would matter if it was from a Z06)
I didn’t remove any coil packs.
Hi,
Did you do the "does it start?" plug test that I mentioned in my main post?
To answer your question above, you will likely have a plug that does not attach to anything (on my 2002, it was a circular plug). It is hard to tell from your photos, but are you sure you purchased a harness from the same year Corvette? I mentioned the differences, that I know of, in the main post. Also, if you removed your coil packs, verify you remembered to plug them back in. I have seen this missed often when people install longtubes. Keep me updated with what you find out!
-John
Did you do the "does it start?" plug test that I mentioned in my main post?
To answer your question above, you will likely have a plug that does not attach to anything (on my 2002, it was a circular plug). It is hard to tell from your photos, but are you sure you purchased a harness from the same year Corvette? I mentioned the differences, that I know of, in the main post. Also, if you removed your coil packs, verify you remembered to plug them back in. I have seen this missed often when people install longtubes. Keep me updated with what you find out!
-John
Thread Starter
Heel & Toe
Joined: Sep 2018
Posts: 16
Likes: 26
From: Mobile
Understood. If it is cranking over, and you did not touch anything else in the engine bay (like the coilpacks, crank sensor, TPS, MAF, etc), my next guess would be to check the rear ground that connects to the frame behind the rear wheel. Make sure it is very clean & tight. I believe this is where the fuel pump is grounded to, so it would make sense if it just cranks & does not start. Also, verify the ground wire on the back of the engine head was reconnected & bolted tight. Can you hear the fuel pump prime when you turn the key to the "acc postion?"
Intermediate
Joined: Jun 2023
Posts: 26
Likes: 3
I’ll check the fuel rail.
All of the spark plugs were recently replaced.
I didn’t touch the cam or crank sensor plug, however I’ll double check to be sure.
I’ll report back once I check.
thank you!
All of the spark plugs were recently replaced.
I didn’t touch the cam or crank sensor plug, however I’ll double check to be sure.
I’ll report back once I check.
thank you!