E40 ECM causing transmission issues in LS2 swap 69 Firebird

[Havoc84]

Hi everyone,

I have a 1969 Firebird with a LS2 from a 2005 corvette (along with the cars pedal and E40 ECM) that is paired to a 4L60E that has been giving me nothing but trouble. My car is just about finished (25k paint, with almost $60k total into the car now) but I'm having a very weird issue. The issue I thought was from the transmission it-self but I was apparently wrong. The car will drive fine for about 20 mins and then it starts to bog down almost like something is applying the brakes and it gets progressively worse while at the same time the trans temp starts to shoot up which I have seen 250 degrees briefly just trying to get the car back home.

I rebuilt the 4L60E (came from a 2002 trans am) and still had the issue. So I thought I goofed something up on the rebuilt (I am a A&P with more than 20 years exp) and I tore the trans apart and put it back together a few times just double and triple checking everything. The same problem was still there after driving 20 or so mins. So then I bought a new level 2 Performabuilt 4L60E and put that in thinking that this was the ultimate fix, but again after 20 mins the damn problem was still there (talk about a $3k gut punch). So while I did get some of my faith restored knowing that the trans I rebuilt was probably just fine.

So I am trying to narrow down and find the root cause still. The last thing I tried was I purchased a VCX Nano and paired the TCM to the E40 since the T42 was the only item I wasn't able to get from the donor car. The T42 I purchased was also from a 2005 corvette A4, but just to ensure that the link between the ECM and TCM was good I got and paired the SPS programing on both to pair them. The issue was still there...

I am relatively new to HP Tuners but I am far from an expert, yet know enough to get around and understand most of it.

Below is a few things I have tried and as well as things I have checked.

• Pair the ECM to TCM with SPS programming
• Segment swap 05 GTO TCM settings since the setup is no longer a transaxle
• Raised the misfire tables by 20%
• No DTC's are or have been present Both ECM or TCM
• Verified VSS signal is accurate with GPS
• Removed all TCM TQ Management (Abuse as well)
• Turned off mil light and set to no error reported for the most common swap config settings
• disabled catylist settings
• Used BlueCat to setup gear and tire settings since I have a 2700 rpm stall.

I have attached the stock minus vats delete tune I have just in case anyone wanted to reference the current settings I have. I have thrown everything and the kitchen sink at this I believe so I hope someone can help me. I would even pay someone for their time if they could help fix this. The next thing I was contemplating next is buying a Holley Terminator Max (Another $1700) since I have a feeling the issue is being caused by the ECM but I don't want to buy another one unless someone on here can help me verify the one I have is bad.

I'm at the end of the road and I just don't know what else I can do. If a new engine management system does it then I would happily pay for it, but I don't want to do that if it won't it.

Sorry one last idea that crossed my mind is possibly geting a 05 GTO Vin and SPS program the ECM and TCM I have to a 2005 GTO with the A4 (if there is something that HP tuners can't change being there are 2 areas that HP tuners doesnt see or show.

[blindsquirrel]

If you want a GTO TCM just SPS it using a GTO VIN. Segment swap is not the way to do that.

Have all the various transmissions been the same application, 13-pin like from the ancient 2002 F body? For use with a later TCM OS I'd think you would be much better off with the correct 15-pin trans.

[Havoc84]

That is a good question and I just went to look to see what I have. The BP automotive harness 15 wires and pins. The connector on the trans itself only has 13 mins. Is this what is causing my issue you think Blindsquirrel?

[Havoc84]

What are the extra two wires for? and can I drop the pan and change out the trans harness for a 15 pin setup? I don't believe I can return the Level 2 I got from performabuilt now.

[blindsquirrel]

2002 F Body Document ID 695198.pdf
2005 GTO Document ID 1506258.pdf

[Havoc84]

Thanks for the comparison PDF's. So the extra two wires would be for ISS which I do not believe the 2005 corvettes had. The trans pin outs between the 2002 trans am and 05 GTO appear to be the same. Since the 05 GTO's didn't have ISS Id imagine flashing SPS programming to a 05 GTO A4 (ECM and TCM) would rectify this problem? unless I am missing something here. (I searched everywhere online trying to research if 2005 A4 corvettes has ISS but it doesn't appear so?

[Alvin]

Hi everyone,

I have a 1969 Firebird with a LS2 from a 2005 corvette (along with the cars pedal and E40 ECM) that is paired to a 4L60E that has been giving me nothing but trouble. My car is just about finished (25k paint, with almost $60k total into the car now) but I'm having a very weird issue. The issue I thought was from the transmission it-self but I was apparently wrong. The car will drive fine for about 20 mins and then it starts to bog down almost like something is applying the brakes and it gets progressively worse while at the same time the trans temp starts to shoot up which I have seen 250 degrees briefly just trying to get the car back home.

I rebuilt the 4L60E (came from a 2002 trans am) and still had the issue. So I thought I goofed something up on the rebuilt (I am a A&P with more than 20 years exp) and I tore the trans apart and put it back together a few times just double and triple checking everything. The same problem was still there after driving 20 or so mins. So then I bought a new level 2 Performabuilt 4L60E and put that in thinking that this was the ultimate fix, but again after 20 mins the damn problem was still there (talk about a $3k gut punch). So while I did get some of my faith restored knowing that the trans I rebuilt was probably just fine.

So I am trying to narrow down and find the root cause still. The last thing I tried was I purchased a VCX Nano and paired the TCM to the E40 since the T42 was the only item I wasn't able to get from the donor car. The T42 I purchased was also from a 2005 corvette A4, but just to ensure that the link between the ECM and TCM was good I got and paired the SPS programing on both to pair them. The issue was still there...

I am relatively new to HP Tuners but I am far from an expert, yet know enough to get around and understand most of it.

Below is a few things I have tried and as well as things I have checked.

• Pair the ECM to TCM with SPS programming
• Segment swap 05 GTO TCM settings since the setup is no longer a transaxle
• Raised the misfire tables by 20%
• No DTC's are or have been present Both ECM or TCM
• Verified VSS signal is accurate with GPS
• Removed all TCM TQ Management (Abuse as well)
• Turned off mil light and set to no error reported for the most common swap config settings
• disabled catylist settings
• Used BlueCat to setup gear and tire settings since I have a 2700 rpm stall.

I have attached the stock minus vats delete tune I have just in case anyone wanted to reference the current settings I have. I have thrown everything and the kitchen sink at this I believe so I hope someone can help me. I would even pay someone for their time if they could help fix this. The next thing I was contemplating next is buying a Holley Terminator Max (Another $1700) since I have a feeling the issue is being caused by the ECM but I don't want to buy another one unless someone on here can help me verify the one I have is bad.

I'm at the end of the road and I just don't know what else I can do. If a new engine management system does it then I would happily pay for it, but I don't want to do that if it won't it.

Sorry one last idea that crossed my mind is possibly geting a 05 GTO Vin and SPS program the ECM and TCM I have to a 2005 GTO with the A4 (if there is something that HP tuners can't change being there are 2 areas that HP tuners doesnt see or show.

I don't like the idea of a Vette ecm going with a GTO T42 just because of the trans axle difference. I like to set up swaps in a config that mirrors a OEM build. So whatever pedal, throttle body, ECM, OS, TCM etc all come out of the same vehicle.

I would not think this is a tuning issue. Perhaps some sort of odd wiring issue. Are you sure the cooler is flowing well when this happens? If cooler flow is blocked the trans will not pull like it should and I would expect temps to raise.

[Havoc84]

Thanks Alvin,

I originally tried keeping everything original programming wise to the 05 vette. I thought just changing the OSS output signal location to after the gear box and revising the ECM and TCM gear ratios would put me on the right track but it would actually cause the issue to come on much sooner. The wire harness is from BP automotive and while the connector on the trans itself is 13 pin the harness connector from the vehicle is a 15 pin but the two extra wires are for ISS if the setup had one which I do not have (Nor does it appear 05 C6's had ISS either). The BP harness was specifically made for my E40 and 4L60E setup which I didn't think I would have much trouble getting is running and operating correctly with only turning off the unnecessary items in the tune.

Also I have good cooler flow. I disconnected one of the lines and put it in a bucket and fired up the car for 20 seconds and got quite a bit of fluid (probably 2-3 quarts). I am at a loss and being frustrated with this car would be an understatement haha

[Alvin]

Thanks Alvin,

I originally tried keeping everything original programming wise to the 05 vette. I thought just changing the OSS output signal location to after the gear box and revising the ECM and TCM gear ratios would put me on the right track but it would actually cause the issue to come on much sooner. The wire harness is from BP automotive and while the connector on the trans itself is 13 pin the harness connector from the vehicle is a 15 pin but the two extra wires are for ISS if the setup had one which I do not have (Nor does it appear 05 C6's had ISS either). The BP harness was specifically made for my E40 and 4L60E setup which I didn't think I would have much trouble getting is running and operating correctly with only turning off the unnecessary items in the tune.

Also I have good cooler flow. I disconnected one of the lines and put it in a bucket and fired up the car for 20 seconds and got quite a bit of fluid (probably 2-3 quarts). I am at a loss and being frustrated with this car would be an understatement haha

Maybe a line is sucking shut or collapsing after a while.