TCCS Torque Converter Clutch Solenoid

TCCS Torque Converter Clutch Solenoid

The torque converter clutch solenoid is mounted on the valve body. The signal is Pulse Width Modulated at 32Hz to provide closed loop control of the pressure across the converter clutch plates. 1 bit = 0.39% Range 0 to 100%

TCS Torque Converter Slip

Torque converter slip is defined as the difference between the input/turbine (ni) speed and the Engine speed (Ne): Slip = Ne-Ni. The PWM duty cycle may increase from 0 to 100% when TCC is fully applied. In practice a 100% duty cycle will be achieved only if a large slip is detected. Normally only a 60 to 95% duty cycle will be required for full application of the TCC. Slip is expressed in rpm. 1 Bit - 1/8 rpm. Range -4096 to +4096 rpm.

TCSW Transmission Control Switch

A three position switch allows the driver to select Sport, Normal or 1st Gear Inhibit mode. When 'Sport' is selected gearshifts take place at higher engine revs. When '1st Gear Inhibit' is selected, the transmission only operates in the higher forward ratios to prevent wheel slip in icy conditions.

TISSA Turbine Input Shaft Speed

Turbine speed is the speed of the input shaft of the transmission measured by the input speed sensor mounted on the transmission. An alternating waveform is induced in the sensor by 31 serrations on the forward clutch housing as it rotates. The waveform frequency and amplitude is low at low speeds and high at high speeds. The TCM changes this signal into a digital signal. 1 bit = 1/8 RPM. Range: 0 - 8192 RPM.

TOS+ Transmission Output Speed

The output speed sensor is mounted on the transmission case and measures the speed of the output shaft. As the shaft rotates an alternating waveform is induced in the sensor which varies in frequency and voltage. The wave form is converted into a digital signal by the TCM and used to control TCC, line pressure, shift timing and torque management. 1 bit = 1/8 RPM. Range 0 - 8192 RPM

TOT Transmission Oil Temperature

The transmission temperature sensor signal is used to control TCC and line pressure. It has a negative temperature coefficient so when the temperature is cold its resistance is high and the TCM sees a high voltage. As the temperature warms the volts drop across the sensor decreases and the signal voltage becomes lower. The TCM converts this analogue input into a digital signal.

1 bit = 1°C Range -55°C to +200°C.

TP Throttle Position

This is provided by the EECV Engine Management System as a Pulse Width Modulated signal derived from the throttle position signal read by that module from the throttle position sensor.

TRX Transmission Control Switch X

TRY Transmission Control Switch Y

TRZ Transmission Control Switch Z

The transmission range is detected by the pressure switch manifold (PSM) and input to the TCM. The signal consists of three discrete lines X, Y, Z which transmit a 3 bit binary code as shown in the table below.

0 = open circuit

1 = short circuit to ground

VS Vehicle Speed

Vehicle speed is derived from a pulsed wave form generated by the speed sensor in the hypoid unit. There are 40 pulses per shaft rotation and the TCM converts this to vehicle speed and applies correction for axle ratio and road wheel diameter. 1 bit - 1kph. Range 0 - 255kph

Transmission Diagnostic Trouble Codes

The diagnostic trouble codes supported by the GM 4L80-E Transmission Control Module are covered in detail in the DB7 OBD II Diagnostics Manual.