Honda Acura NSX 1991, Service Manual, Page: 762 / 1420

System Description
Outline
Role of System
The NSX traction control is a variable system designed to enhance traction during acceleration and cornering. It does
so by determining the optimum amount of wheel spin for any given driving situation, then suppressing surplus engine
power accordingly.
Construction and Function
The TCS control unit gets signals about the vehicle’s speed, direction, and road conditions from sensors at the wheels
and the steering column. Based on these signals, the control unit will determine the optimum amount of wheel spin.
Because the system is variable, the control unit may determine, depending on the driving conditions, that some wheel
spin is beneficial (thus enhancing straight-line acceleration), or that no wheel spin is beneficial (thus enhancing corner-
ing). For any given driving situation, the control unit will determine the amount of wheel spin best suited to the driver’s
needs and, if necessary, will then signal the throttle actuator and PGM-FI control unit to reduce engine power.
The system is automatically “ready” whenever the engine is started, but can be manually canceled with the TCS switch.
However, once activated, the system cannot be canceled until it is once again in the ready state.
STEERING WHEEL SENSOR THROTTLE
ANGLE SENSOR RIGHT) BODY
WHEEL
CONTROL
WHEEL SENSOR
(FRONT RIGHT)
UNIT
(REAR LEFT)
WHEEL SENSOR
(FRONT LEFT)
Components:
Wheel sensors. The TCS “shares” the wheel sensors with the Anti-lock brake system. The wheel sensors transmit
wheel speed signals to the TCS through the Anti-lock brake system control unit.
l
Steering angle sensor. The steering angle sensor signals the TCS control unit about the amount of steering angle.
l
Throttle actuator. The throttle actuator gets signals from the TCS control unit and closes the throttle valve accordingly.
l TCS control unit. The control unit gets driving condition signals from the sensors and, if necessary, signals the throttle
actuator to close the throttle valve and engine control unit (PGM-FI control unit).