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E38 + T42 VSS problem?

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Old 09-17-2009, 12:59 PM
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Default E38 + T42 VSS problem?

Heres my setup. Motor is '07 Escalade L92, using E38 with an Escalade OS, mated to a '96 4L60E and a T42 with '06 GTO Calibration. Car starts and drives, transmission shifts. My problem comes in, I can drive with the pedal to the floor, but the throttle body only opens like 40%. I also dont show vehicle speed on the scanner display, which is leading me to believe there is some kind of VSS signal issue? There are no codes being set, and im using 120Ohm resistor as a terminator on the second set of GMLAN wires out of the T42. This is driving me absolutely nuts. I see on the wiring diagrams that E38 has a pin72 for VSS LO SIG. On the harness that came with the motor that pin was never in use, I tried connecting that to the VSS wire direct, no change. Tried to connect it to pin5 on the T42, which in the GTO diagram is labeled VSS and goes to the VSS on the ECM, no luck there either. Can someone shed some light on this?
Old 09-18-2009, 04:00 AM
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Originally Posted by 12SEC SS
Heres my setup. Motor is '07 Escalade L92, using E38 with an Escalade OS, mated to a '96 4L60E and a T42 with '06 GTO Calibration. Car starts and drives, transmission shifts. My problem comes in, I can drive with the pedal to the floor, but the throttle body only opens like 40%. I also dont show vehicle speed on the scanner display, which is leading me to believe there is some kind of VSS signal issue? There are no codes being set, and im using 120Ohm resistor as a terminator on the second set of GMLAN wires out of the T42. This is driving me absolutely nuts. I see on the wiring diagrams that E38 has a pin72 for VSS LO SIG. On the harness that came with the motor that pin was never in use, I tried connecting that to the VSS wire direct, no change. Tried to connect it to pin5 on the T42, which in the GTO diagram is labeled VSS and goes to the VSS on the ECM, no luck there either. Can someone shed some light on this?
Pin 72 is for manual VSS only. A4 doesnt need it as it is already processed in the TCM.

What pedal are you using?
Old 09-18-2009, 10:51 AM
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Originally Posted by rsz288
Pin 72 is for manual VSS only. A4 doesnt need it as it is already processed in the TCM.

What pedal are you using?
Im using an '06 Corvette pedal. I have no issues revving at idle, with ignition on and car off, i can floor the pedal and throttle body opens all the way. I tried locking the trans in first with hptuners, and when i try to drive, it starts bouncing off of rev limiter at 4k rpm. I grounded two of the safety neutral switch wires, so my scanner shows that its in drive, and still same issue..
Old 09-18-2009, 05:17 PM
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Originally Posted by 12SEC SS
Im using an '06 Corvette pedal. I have no issues revving at idle, with ignition on and car off, i can floor the pedal and throttle body opens all the way. I tried locking the trans in first with hptuners, and when i try to drive, it starts bouncing off of rev limiter at 4k rpm. I grounded two of the safety neutral switch wires, so my scanner shows that its in drive, and still same issue..
If your ECM is 100% from an Escalade (originally came in the same Escalade as the OS that is in it), your problem would go away with an Escalade pedal. The ECM is going into reduced power mode as it is detecting an electronic throttle control issue.



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