9-7X V8-5.3L (2005)
To improve product quality, reduce warranty cost and be common with other transmissions, an input speed senor (ISS) assembly (250) has been
designed into the oil pump cover. This new component makes the 4L60-E common with other Hydra-Matic(TM) electronic transmissions by enabling
algorithm (computer instructions) such as shift energy and abuse torque management, as well as improved transmission diagnostic capabilities, designed
to reduce the K9995 labor operation (cannot duplicate). The ISS assembly (250) is a three-wire hall-effect sensor that is mounted internally to the
transmission oil pump assembly. The ISS utilizes the rotor teeth located on the turbine shaft to generate a voltage signal of varying frequency that
corresponds to the rotational speed of the turbine shaft. The ISS signal is an input to the transmission control module (TCM) and is used to determine
line pressure, transmission shift patterns, torque converter clutch (TCC) slip speed and gear ratio.
Input Speed Sensor (ISS) Service Considerations
Because the ISS connector (3) is located below the pressure regulator (PR) valve, it blocks the entrance to the PR valve line up. This now prevents the
ability to remove the PR valve while the transmission is in the vehicle. This procedure can only be completed with the pump removed from ISS-equipped
transmission.
The ISS assembly wiring is attached to the pump cover with two steel brackets (1 and 2) which are pushed in place onto the pump casting. The bracket
locations are important in order to ensure the harness lies flat against the pump cover, preventing contact with the rotating reverse input clutch housing.
Avoid distorting the ISS wiring brackets when prying them from the pump cover. If the brackets don't hold tightly to the pump surface, the ISS assembly
must be replaced.
For transmission models that do not use an input speed sensor, an ISS hole plug assembly (248) is used to block the machined bore. The ISS plug
incorporates the same 0-ring seal as the ISS assembly, and if omitted or damaged during repair, it could produce objectionable TCC operation. To aid
the installation of the ISS into the pump cover, the 0-ring should be lubricated with transmission oil.
Transmission Internal Wiring Harness
