2005 and up G.M. Trucks equipped with the 4L60/65/70E transmission may exhibit a complaint of Torque Converter slip when the vehicle is hot, accompanied by a Diagnostic Trouble Code P0894, Component Slip. This complaint usually occurs after an overhaul and/or after the repair of the TCC Regulator valve bore.
The cause may be that during the rebuild process, the TCC PWM solenoid was not replaced (figure 1), as the symptom mimicked that of a worn out TCC regulator bore. A closer inspection of the solenoid snout (figure 2), shows that a hairline crack caused a loss of solenoid pressure acting on the TCC regulator valve causing the Torque Converter to slip. Thanks go to John Dye from Dye’s Auto and Diesel Repair for the discovery. A new TCC PWM Solenoid (part number 24207054) costs approximately $30.00.
