A/T - Chuggle or TCC Growl on Grades
File in Section: 6E - Engine Fuel & EmissionBulletin No.: 47-65-21
Date: January, 1995
Subject:
Chuggle or TCC Growl on Grades while Maintaining Speed with TCC Engaged (Replace EPROM)
Models:
1993 Buick Skylark
1993 Oldsmobile Achieva
1993 Pontiac Grand Am
with 2.3L Engine (VIN 3 - RPO L4O) and 3T40 Transaxle (MD9)
Condition
Some customers may comment about a chuggle or TCC growl while maintaining a steady speed on grades or inclines. This will usually occur around 40 - 45 MPH.
Cause
Software calibration allowing TCC to apply at 43 MPH.
Correction
If no cause is found for the above conditions after following currently published diagnostics, replace the EPROM using the part number listed. The TCC calibration has been revised to increase TCC apply speed to 49 MPH to correct this condition.
Service Information
Perform diagnostics per Section 6E in the Service Manual. Make any adjustments that are required, or replace any inoperative parts.
If no cause is found for the chuggle or growl following currently published diagnostics, replace the EPROM using the part numbers listed below.
Refer to the applicable Service Manual for the EPROM replacement procedure.
Parts Information
Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty use: