76 Power-Up at Speed

THEORY OF OPERATION:
If a vehicle loses power to the TCM, the vehicle will go to the 2nd gear mode since there is no power available to control the transmission solenoids. However if power is restored, the TCM will power-up and normal operation will be restored. (Beginning in 1997)

Beginning with the 97MY a trouble code 76 is introduced that identifies that power to the TCM was restored when the gear selector was in a "Drive" position while the vehicle was moving at speeds above 20 MPH. Unfortunately, if a person shifts to Neutral and cycles the ignition key and quickly shifts to "Drive" while moving before the TCM comes out of its START ROUTINE, the fault can be set. Therefore it is critical that this trouble code diagnosis repair procedure should only be used if the vehicle is experiencing intermittent 2nd gear operation and subsequently a return to normal operation during normal driving.

LIMP-IN:
NO

WHEN MONITORED/SET CONDITIONS:
When TCM initially power-up.

If the TCM powers up while in the "Drive" position and the vehicle is going above 20 MPH, the code is set.

TRANSMISSION EFFECTS:
97MY and later. No limp-in condition. Fault code is for information only when trying to diagnosis intermittent 2nd gear operation and subsequently a return to normal operation.

POSSIBLE CAUSES:
No problem if vehicle is started in "neutral" at speeds above 20 MPH and shifted quickly to "Drive" before TCM comes out of the START ROUTINE.