Catera V6-3.0L VIN R (1997)
Control Module: Customer Interest
A/T - No Scan Tool Communication W/ Trans Control Module
File In Section: 7 - Transmission
Bulletin No.: 77-71-58
Date: April, 1997
INFORMATION
Subject:
Inability to Establish Scan Tool Communication with the Transmission Control Module (TCM)
Model:
1997 Cadillac Catera
with HYDRA-MATIC 4L30E Transmission (ML4) on Vehicles Built from S.O.P. through W06VR52R090366
Some technicians may experience difficulty in establishing scan tool communications with the Transmission Control Module (TCM). The scan tool will
display the message No communication with vehicle, check diagnostic link connector, check ignition on/off."
The TCM software only allows communication when directly addressing the TCM. If communication is initially made with the ECM, communication
with the TCM is not possible.
Establish scan tool communication with the TCM prior to communicating with the ECM. If communication is established with the ECM initially, cycle
the ignition key off for at least 10 seconds, turn the ignition key on and directly address the TCM.
