P1781 ...... Anyone else see it ever ??
Engine Torque Signal ....

Mac http://www.dieselplace.com/forum/smileys/Confused.gif Edited by: Mackin

Was a soft code ,non MIL ....Wish I hade a Tech II for freeze frame info ...http://mail.wackywack.com/forum/smileys/Disapprove.gif





Mac

Here is the code info.
<H1>DTC P1781</H1><A name=ss1-744229><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=744229&amp;psdid=210&amp;evc=sm#ss1-744229" target="_blank">
<H5>Circuit Description</A></H5>


The transmission control module (TCM) malfunction indicator lamp (MIL) request circuit signals the engine control module (ECM) that the TCM is requesting MIL illumination.<A name=ss2-744229><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=744229&amp;psdid=210&amp;evc=sm#ss2-744229" target="_blank">
<H5>Conditions for Running the DTC</A></H5>


The ignition is ON.<A name=ss3-744229><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=744229&amp;psdid=210&amp;evc=sm#ss3-744229" target="_blank">
<H5>Conditions for Setting the DTC</A></H5>


The ECM is detecting an improper voltage level on the TCM MIL request circuit.<A name=ss1-727820><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=744229&amp;psdid=210&amp;evc=sm#ss1-727820" target="_blank">
<H5>Action Taken When the DTC Sets</A></H5>
<UL =BULLET>
<LI>The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
<LI>The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. </LI>[/list]<A name=ss1-727824><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=744229&amp;psdid=210&amp;evc=sm#ss1-727824" target="_blank">
<H5>Conditions for Clearing the MIL/DTC</A></H5>
<UL =BULLET>
<LI>The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
<LI>A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
<LI>A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
<LI>Clear the MIL and the DTC with a scan tool. </LI>[/list]

Thanks


I assume it means nothing ?? I think there maybe a TSB for the 01's ...


I'm going to have my truck in for some final warranty period work ... I'm going to have to have them recheck all ECM updates ...


Is that TCM related flash ? As I have had none with the exception of what was necessary to activate High Idle ...


Mac

Mac,
check your mail.
Tom

Mack,


You're scaring the crap out of your Allison...http://www.dieselplace.com/forum/smileys/Cool.gif

There is a TSB but it's for the 8.1L.

Mack,


You're scaring the crap out of your Allison...http://www.dieselplace.com/forum/smileys/Cool.gif





No kidding .... The Tri-fecta (actually I have the Predator in on zero too)I was running today I'll garranty would make a stock tranny limp imediately and you'd blow right thru the converter ....Sick right off idle ...http://dieselplace.com/forum/smileys/Shocked.gif





Mac

ouch

have seen the main engine wiring harness (where you plug juice in)seen ths harness have bad pin tension. causing this code..sound crazy. double check the conection.