What does it mean?
The automatic transmission TSS (Turbine Shaft Speed) or ISS (input shaft speed) sensor provides transmission input speed to the transmission control module (TCM). The ISS sensor can be a permanent magnet (PM) generator or a Hall-Effect switch (Creates an on–off square wave signal that is used directly by the PCM/TCM for speed detection). The TSS/ISS sensor mounts into the transmission case and maintains a slight air gap between the sensor and the forward clutch housing.
T As the output shaft and internal gear rotate, the toothed rotor of the internal gear produces AC voltage as the rotor teeth pass through the magnetic field of the sensor of a digital signal if it is a Hall-Effect sensor. The AC voltage level or digital increases as the turbine shaft speed increases. The control module PCM or TCM converts the AC voltage of the PM generator into a digital signal.
The TCM determines actual turbine speed using these signals and uses the input speed to calculate torque converter slip speed, and gear ratios. Speed sensors measure the speeds of the input and output shafts or sometimes of other shaft speeds in the automatic transmission or transaxle. The output shaft speed sensor is often used to provide vehicle speed information to the control module and for adaptive learning.
The output speed sensor (OSS) is also called the vehicle speed (VS) sensor and is used by the PCM for speedometer and cruise control operation as well as for transmission/transaxle operation and shift-related fault detection and if defective will set DTC related to cruise operation.
NOTE: Whenever diagnosing a 700 series DTC (Diagnostic Trouble Code) with a transmission, transfer case or other driveline components, check for a DTC under chassis and body systems, not just under “P” or powertrain/engine or emission control type codes. Module communications DTCs are “U” codes. These are most often found when looking for DTCs under chassis or body systems.
Chassis related codes are labeled “C” and body system related codes are labeled “B” codes and these can cause drivetrain issues if they affect a sensor that is also used by the heating and air conditioning system. Figure 1 TSS/ISS Circuit Wiring Diagram DTC P0715 is detected when the control module TCM or ECM does not receive the right signal from the TSS/ISS sensor.