Scan Tool Data Definitions - Electronic Power Steering (EPS)

TORQUE SENSOR MAIN
This is the input from the detection torque sensor. The detection torque sensor is the first sensor and is considered the main sensor. A negative reading indicates a left turn and a positive reading indicates a right turn. This reading can be displayed in Nm or ft. lbs.

TORQUE SENSOR SUB
This is the input from the compensation torque sensor. The compensation torque sensor is the second sensor. A negative reading indicates a left turn and a positive reading indicates a right turn. This reading can be displayed in Nm or ft. lbs.

TORQUE SENSOR AMPLIFIED
The processor in the EPS control module requires the signal from the detection (main) torque sensor to be amplified. This signal is amplified and is used to compensate for the lag caused by mechanical parts. This is the input after the signal has been amplified. A negative reading indicates a left turn and a positive reading indicates a right turn. This reading can be displayed in Nm or ft. lbs.

ACTUAL MOTOR CURRENT
The actual motor current is the amount of current that the EPS motor is drawing. This reading is displayed in Amps.

DESIRED MOTOR CURRENT
This is the amount of current that EPS control module is requesting from the UPS motor. This reading is displayed in Amps.

MOTOR VOLTAGE +
This is the voltage at the EPS motor. A negative reading indicates a left turn and a positive reading indicates a right turn. This reading is displayed in volts.

MOTOR VOLTAGE -
This is the voltage at the EPS motor. A negative reading indicates a left turn and a positive reading indicates a right turn. This reading is displayed in volts.

VEHICLE SPEED
This is the current vehicle speed. The EPS control module receives this information for either the ECM or the TCM depending upon the application. This EPS control module uses this information to determine the amount of steering assist. This reading can be displayed in kph/mph.

BATTERY VOLTAGE
This is the battery voltage at the EPS control module. This reading is displayed in volts.

LIMITING MOTOR CURRENT
This is the amount of current that the motor last received before it went into overload protection mode. The EPS motor and control module are not designed to handle 65 amps continuously. To prevent damage to the system it will shut down.
The minimum motor current that EPS has limited will be stored. If it indicates 65A, it means that an overload protection event has not occurred.

TUNING PROFILE
The EPS control module must be programmed. The tuning profile is the setting that the EPS module is programmed to. If the EPS module has not been programmed a 0 (zero) will appear, this is the default setting. The EPS control module must be programmed upon replacement with the Saturn Service Stall.

IGNITION VOLTAGE
The EPS control module receives the state of the ignition switch from the Class II serial data line. This display will either be displayed as Yes or No. A Yes indicates that the EPS control module has received the state of the ignition switch and a No indicates that the state of the ignition switch has not been received.

ENGINE RUN
The EPS control module receives the status of the engine from the Class II serial data line. If the display is Yes. then the EPS control module has received data indicating that the engine is running. If the display is No, then the EPS module has received data indicating that the engine is not running.

LOW BATTERY VOLTAGE INCIDENTS
This is the number of times that there has been a low voltage condition. When a low voltage condition occurs, the EPS system will operate at default value. The amount of steering assist may be limited. A diagnostic trouble code (DTC) may be set to aid in the diagnosis. This data display is located under "History Data."

IGNITION CYCLES SINCE LAST CODE SET
This is the number of times that the ignition key has been cycled since the last DTC has been set in the EPS control module. This data display is located under "History Data."

OVERLOAD PROTECTION INCIDENTS
This is the number of times that the EPS system entered into overload protection mode. A diagnostic trouble code (DTC) may be set to aid in the diagnosis. This data display is located under "History Data."