Throttle Control

Throttle Control

Sensor Power Supply Monitor

High/Low Input Failure
These are continuous monitors. The voltage from the supply is compared to a failure threshold defined in the software. If the voltage is below the low threshold, then a timer starts to increment. Once this timer exceeds another threshold, then a failure flag is set and a DTC is stored. If the voltage exceeds the high threshold defined in the software, then a timer starts to increment. Once this timer exceeds a threshold, then a failure flag is set and a DTC is stored.

Malfunction
The outputs from two TP sensors and one pedal demand sensor are checked. If they ALL fall below a threshold value then a counter is incremented, otherwise the counter is reset to zero. If the counter reaches a calibrated value, a failure judgment is made.

Analogue Ground Monitor
The output voltages from the following sensors are checked:
- TP sensor 1
- TP sensor 2
- APP sensor 2
- FTP sensor (on USA market cars)
- IAT sensor
- ECT sensor
- IAT sensor after charge air cooler (on supercharged cars)
- Fuel rail pressure sensor
- Intake manifold pressure sensor
- Oil temperature sensor

If they all fall below a threshold value then a counter is incremented, otherwise the counter is reset to zero. If the counter reaches a calibrated value a failure judgment is made.

Throttle Actuator Control Monitor

Throttle Actuator Control OBDII Position Error
During ignition on conditions the calculated target throttle voltage is compared to the actual TP sensor voltage. If the voltage of the target and actual throttle signal differ by more than a calibratable amount for more than a calibratable period a failure judgment is made.

Throttle Actuator Control OBDII Circuit Malfunction
During ignition on conditions, the throttle motor current signal is monitored by hardware. If an over current condition is detected for more than a calibratable period, a failure judgment is made. During ignition on conditions, the throttle motor current is monitored by software. If the throttle motor current is more than a calibration level for more than a calibratable period a failure judgment is made. During ignition on conditions, the PWM throttle motor duty is monitored. If 100% duty cycle is detected for more than a calibratable period a failure judgment is made.

Throttle Motor Relay Monitor

DC Motor Relay Off Failure
During ignition on the relay driver signal is compared with the relay output signal. If the ECM is commanding the relay on and detecting the relay as off for more than a calibratable period, a failure judgment is made.

DC Motor Relay On Failure
During ignition on the relay driver signal is compared with the relay output signal. If the ECM is commanding the relay off and detecting the relay as on for more than a calibratable period, a failure judgment is made.

Throttle Motor Relay Driver Monitor

DC Motor Relay Driver Off Failure
During ignition on the relay driver target flag is compared with the relay driver signal. If the ECM is commanding the relay on and detecting the relay driver as off for more than a calibration period, a failure judgment is made.

DC Motor Relay Driver On Failure
After ignition off, the ECM sets the relay driver off. This is compared with the relay driver monitor. If the ECM is commanding the relay off and detecting the relay driver as on for more than a calibration period, a failure judgment is made.

Throttle Return Spring Monitor
After ignition off, the throttle blade is moved by the throttle motor to a calibrated position. The motor is then turned off. The monitor checks that the throttle blade is moved by the return spring. If movement of less than a calibrated amount is detected, a failure judgment is made.

Throttle Limp Home Spring Monitor
After ignition off, the throttle blade is moved by the throttle motor to a calibrated position. The motor is then turned off. The monitor checks that the throttle blade is moved by the limp-home spring. If movement of less than a calibrated amount is detected, a failure judgment is made.

Throttle Watchdog Monitor
After ignition off, the watchdog pulse is stopped in order to check whether the throttle motor relay driver will be disabled. If the throttle motor relay driver command is detected on for more than a calibratable period, a failure judgment is made.