Closed Throttle Coast Surge Or Chuggle After Calibration - keywords 5L40E 5L50E automatic calibrate convreter engage torque

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Customers may comment on a surge during coast or deceleration. Typical speeds will range from approximately 55 down to 40 mph but may vary due to tire size and gear ratio. Technicians may find that the tcc is being commanded on and off during the surge event. The surge condition would not have appeared until after the TCM calibration listed as "To be used ONLY for customer complaint of low speed chuggle under light throttle input while going up slight grades" was installed.

Engineering is aware of the concern and investigating a correction at this time. Replacement of any components will not correct this concern. Please contact TAC at the number you have been provided to set a case for tracking purposes only. Please make available the vehicle speed, ECM and TCM calibration numbers currently being used in the vehicle when calling TAC.

Note: This PI will be updated when a correction becomes available.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.