With Generic Scan Tool
PROCEDURE
NOTE: Automatic Transmission related trouble codes can not be accessed from the A/T control unit using a generic scan tool (GST).
Only those codes that are shared (and stored simultaneously) by the ECM and A/T control units can be retrieved with a GST, and then only through the ECM.
Any other trouble codes that are stored within the A/T control unit must be retrieved using the OE scan tool (Consult) or by manually initiating the self-diagnostic sequence within the A/T control unit as described below.
Procedure Without Scan Tool
