1998-2007 Cars And Light Duty Trucks TCC Operation - keywords shudder slip surge speed

This PI was superseded to update Recommendation/Instructions, Please discard PIP4001.

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

Light duty trucks/utilities and cars equipped with a 4L60E, 4L65E or 4L70E automatic transmission have a transmission calibration feature called electronically controlled capacity clutch. This feature is often referred to as ec cubed or ECCC.

These transmissions are equipped with an electronically controlled capacity clutch (ECCC). The pressure plate does not fully lock to the torque converter cover. Instead, the pressure plate maintains a small amount of slippage, about 20 RPM, in SECOND, THIRD and FOURTH gears, depending on the vehicle application. ECCC was developed to reduce the possibility of noise, vibration or chuggle caused by TCC apply. Typical apply speeds are 49-52 km/h (30-32 mph) in THIRD gear and 65-73 km/h (40-45 mph) in FOURTH gear. Full lockup is available at highway speeds on some applications.

Technicians may also notice the tcc stays applied on coast closed throttle or until the brake is applied. This is also part of the ECCC calibration. TCC slip speed should range between 20 and 80 rpm but may drop as low as 0 and as high as 100 rpm depending on load and road conditions and may be heard through exhaust or seen on the tachometer. Any modifications to the vehicle i.e. exhaust, air cleaner or tire size may effect ECCC operation and make it more noticeable to the technician and customer.

No repair attempts should be made on the above conditions as they are considered operating characteristics.

Note: The above information does not apply to the Parallel Hybrid Truck (PHT)

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.