Component Description
EGR volume control valve
The EGR volume control valve uses a step motor to control the flow rate of EGR from exhaust manifold. This motor has four winding phases. It operates according to the output pulse signal of the ECM. Two windings are turned ON and OFF in sequence. Each time an ON pulse is issued, the valve opens or closes, changing the flow rate. When no change in the flow rate is needed, the ECM does not issue the pulse signal. A certain voltage signal is issued so that the valve remains at that particular opening.
EGR Temperature Sensor
The EGR temperature sensor detects temperature changes in the EGR passageway. When the EGR volume control valve opens, hot exhaust gases flow, and the temperature in the passageway changes. The EGR temperature sensor is a thermistor that modifies a voltage signal sent from the ECM. This modified signal then returns to the ECM as an input signal. As the temperature increases, EGR temperature sensor resistance decreases.
This sensor is not directly used to control the engine system. It is used only for the on board diagnosis.
Reference data
| EGR temperature °C (°F) | Voltage(1)V | Resistance MΩ | ||
|---|---|---|---|---|
| 0 (32) | 4.59 | 0.73 - 0.88 | ||
| 50 (122) | 2.32 | 0.074 - 0.082 | ||
| 100 (212) | 0.62 | 0.011 - 0.014 | ||
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When EGR system is operating.
Voltage: 0 - 1.5V