4l70 problems
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4l70 problems I'm installing a ls2 4l70 combo in my 67 camaro with Chevrolet performance harness for both the engine and transmission.Got it up and running yesterday but the transmission won't shift out of first but I do have reverse and the mil light is not showing an error code. Were to start?
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I have that connection made.would a bad sensor show up as an error code? I was able to to get pulses for the Speedo to my vhx gauges also
Last edited by mlc 67'; Apr 11, 2016 at 07:36 AM.
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Yes, the VSS sensor should only be wired to the PCM. The PCM has an output signal to run an electronic speedometer.
Then connect a scanner to the OBD2 port and confirm that the scanner's displayed MPH more-or-less agrees with you speed.
Also be sure the TCM (which I assume you have) is properly connected to the PCM so that it also sees the VSS signal.
Then connect a scanner to the OBD2 port and confirm that the scanner's displayed MPH more-or-less agrees with you speed.
Also be sure the TCM (which I assume you have) is properly connected to the PCM so that it also sees the VSS signal.
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a few pics of my project Yes, the VSS sensor should only be wired to the PCM. The PCM has an output signal to run an electronic speedometer.
Then connect a scanner to the OBD2 port and confirm that the scanner's displayed MPH more-or-less agrees with you speed.
Also be sure the TCM (which I assume you have) is properly connected to the PCM so that it also sees the VSS signal.
Then connect a scanner to the OBD2 port and confirm that the scanner's displayed MPH more-or-less agrees with you speed.
Also be sure the TCM (which I assume you have) is properly connected to the PCM so that it also sees the VSS signal.
As far the Speedo wiring with the connect and cruise it is really staight foward there one wire in the trans harness marked speed output and just as simple for the Dakota digital gauges. I will disconnect it and see what happens. But i think I will bum the neighbors scan tool fitst. Thanks for the help
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error codes question Finally had a chance to hook-up the camaro to computer. The transimission wasn't showing any error codes but the engine had three p0341. P2101. P2119. One is for the cam sensor. The others are for the trottle position sensor. So my question is I'm using a tbss trottle body and the corvette pedal from the gm performance kit. I'm I going to have to change to the corvette style trottle body or have the ecm reprogramed or just a bad trottle sensor or would a bad cam sensor mess everything up. I'm pretty sure the cam sensor is bad because it has hard starts some times and has total engine shut down on occasionally
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The cam code is not affecting the trans, but the TB codes might be.
The TB, ECM and Pedal have to be compatible.
Did the scanner show a reasonable MPH while driving?
Once you get the trans shifting, I either help you with the cam sensor or suggest you start a new thread in another section.
The TB, ECM and Pedal have to be compatible.
Did the scanner show a reasonable MPH while driving?
Once you get the trans shifting, I either help you with the cam sensor or suggest you start a new thread in another section.
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I don't know what it was showing for mph but it wasn't commanding the trans to shift to second. Also with out the gas pedal pressed the trottle body was reading 25%
Last edited by mlc 67'; Oct 8, 2016 at 02:23 PM.
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tcu is not showing any vechicle speed tps or rpms Does my transmission need the tiss hooked up to work? Chevolet performance tech says not. But they haven't come up with any ideas to make it work. From what I can tell the main transmission harness looks to be right. I know 09 Doesn't work with the kit, but08 should. The ecm is free of any error codes now and is reading all the values correctly according to the scanner
Last edited by mlc 67'; Oct 8, 2016 at 02:46 PM.
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If you had a "stock" '07+ ECM I would say yes you need the ISS (Input Speed Sensor) hooked up. But the "Performance kit" parts may be more flexible. If you don't have any codes, you probably don't need the ISS.
In any case I don't think a missing ISS will not prevent the trans from shifting.
You really need to hook up a scanner that can command any gear to determine if the problem is in the TCM, the harness or the trans (which I doubt).
You mention the "Chevrolet performance harness" but perhaps this does not include the ECM and TCM; in that case please tell us exactly where the ECM and TCM came from and ideally their part numbers. Also the pedal part #. It sounds like the ECM is not talking to the TCM.
In any case I don't think a missing ISS will not prevent the trans from shifting.
You really need to hook up a scanner that can command any gear to determine if the problem is in the TCM, the harness or the trans (which I doubt).
You mention the "Chevrolet performance harness" but perhaps this does not include the ECM and TCM; in that case please tell us exactly where the ECM and TCM came from and ideally their part numbers. Also the pedal part #. It sounds like the ECM is not talking to the TCM.
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part numbers If you had a "stock" '07+ ECM I would say yes you need the ISS (Input Speed Sensor) hooked up. But the "Performance kit" parts may be more flexible. If you don't have any codes, you probably don't need the ISS.
In any case I don't think a missing ISS will not prevent the trans from shifting.
You really need to hook up a scanner that can command any gear to determine if the problem is in the TCM, the harness or the trans (which I doubt).
You mention the "Chevrolet performance harness" but perhaps this does not include the ECM and TCM; in that case please tell us exactly where the ECM and TCM came from and ideally their part numbers. Also the pedal part #. It sounds like the ECM is not talking to the TCM.
In any case I don't think a missing ISS will not prevent the trans from shifting.
You really need to hook up a scanner that can command any gear to determine if the problem is in the TCM, the harness or the trans (which I doubt).
You mention the "Chevrolet performance harness" but perhaps this does not include the ECM and TCM; in that case please tell us exactly where the ECM and TCM came from and ideally their part numbers. Also the pedal part #. It sounds like the ECM is not talking to the TCM.
IIRC on the GMPP harness, there are 2 plugs for the VSS one on the trans harness and 1 on the engine side harness.
I don't recall which one but when pluged into 1 of them it does exactly as you described. I want to say when it's plugged into the trans side the engine side can't see it and it won't allow it to shift.
I think, it needs to be plugged into the engine side harness to work properly and not the trans side.
The trans controller then reads the VSS signal through the engine side.
I don't recall which one but when pluged into 1 of them it does exactly as you described. I want to say when it's plugged into the trans side the engine side can't see it and it won't allow it to shift.
I think, it needs to be plugged into the engine side harness to work properly and not the trans side.
The trans controller then reads the VSS signal through the engine side.
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IIRC on the GMPP harness, there are 2 plugs for the VSS one on the trans harness and 1 on the engine side harness.
I don't recall which one but when pluged into 1 of them it does exactly as you described. I want to say when it's plugged into the trans side the engine side can't see it and it won't allow it to shift.
I think, it needs to be plugged into the engine side harness to work properly and not the trans side.
The trans controller then reads the VSS signal through the engine side.
I don't recall which one but when pluged into 1 of them it does exactly as you described. I want to say when it's plugged into the trans side the engine side can't see it and it won't allow it to shift.
I think, it needs to be plugged into the engine side harness to work properly and not the trans side.
The trans controller then reads the VSS signal through the engine side.
I have done 2 of these now and I remember fighting it on the first one.
On the second one I already knew it was a 50/50 and would just have to swap 1 plug. Luckily it was right the first time around.
Both were LS3's with 4L70E all GMPP part's from the catalog.
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Have you tried swapping them?
I have done 2 of these now and I remember fighting it on the first one.
On the second one I already knew it was a 50/50 and would just have to swap 1 plug. Luckily it was right the first time around.
Both were LS3's with 4L70E all GMPP part's from the catalog.
I have done 2 of these now and I remember fighting it on the first one.
On the second one I already knew it was a 50/50 and would just have to swap 1 plug. Luckily it was right the first time around.
Both were LS3's with 4L70E all GMPP part's from the catalog.
It's likely something in your harness connections. I would go through it again and verify your set up correctly.
I have done 2 of these now. I laid the harness my self on the second one. Once you working correctly you can go into the TCM and program the tire and gear size and adjust shift points as needed.
I have done 2 of these now. I laid the harness my self on the second one. Once you working correctly you can go into the TCM and program the tire and gear size and adjust shift points as needed.