Frequency - The sensor produces an AC signal. The AC signal frequency (Hz) varies as the condition changes.
Pulse width modulated (PWM) - The sensor produces a digital signal. The duty cycle of the digital signal varies as the condition changes and the frequency of the digital signal is constant.
Frequency sensors produce an AC signal. The AC signal frequency (Hz) varies as the condition changes.
| |
| Illustration 1 | g00507191 |
|
Engine Speed Sensor | |
The engine speed sensor is an input to the ECM. The sensor is designed to inform the ECM about the speed of the engine. The ECM uses the information from the speed sensor to calibrate the transmission solenoids and to enable/disable the lockup clutch. The lockup clutch is turned off if the engine speed is too low. The lockup clutch is turned on if the engine speed is too high. This is done to prevent overspeeds of the engine or stalling of the engine.
The engine speed sensor is a frequency sensor. The speed sensor is located on the flywheel housing. The sensor generates an AC signal from the passing ring gear teeth. The ECM measures the frequency of the signal and the ECM responds accordingly to the signal. The engine speed and the diagnostic status of the sensor are available to all modules through the CAT data link.
The engine speed sensor has a connector with two contacts. The sensor connects to the ECM through contacts J1-40 and contact J1-41.
| |
| Illustration 2 | g00585709 |
|
Transmission Output Speed Sensor (1) Transmission Output Speed Sensor (2) Transmission Input Speed Sensor | |
The transmission output speed sensors are an input to the ECM. The transmission output speed sensor informs the ECM about the speed of the transmission output shaft. The ECM uses the information from the transmission output speed sensors in order to properly shift the transmission. The transmission output speed sensor (1) connects to the ECM through contacts J1-63 and contact J1-65. The transmission output speed sensor (2) connects to the ECM through contacts J1-66 and J1-53.
The transmission input speed sensor is an input to the ECM. The transmission input speed sensor informs the transmission ECM about the speed of the transmission input shaft. The ECM uses the information from the sensor in order to validate output speed signals are correct. The ECM also uses the information to aid in calibration of the transmission clutches.
| |
| Illustration 3 | g00507858 |
|
Pulse Width Modulated Signal | |
| |
| Illustration 4 | g00021437 |
|
Schematic for Typical PWM Sensor | |
Pulse width modulated sensors (PWM) produce a digital signal. The duty cycle of the sensor signal varies as the condition changes. The frequency remains constant.
| |
| Illustration 5 | g00507186 |
|
Latching Pressure Sensor | |
The latching pressure sensor is an input to the ECM. The latching pressure sensor provides a pulse width modulated signal to the transmission ECM. The transmission ECM uses the signal from the latching pressure sensor in order to determine the mode of the transmission. The transmission ECM can be in the latched mode or the transmission ECM can be in the unlatched mode.
The latching pressures sensor connects to the transmission ECM through contact J1 -11, J1-12 and J1-62.
Transmission Lube Oil Pressure Sensor
| |
| Illustration 6 | g00507187 |
|
Transmission Lube Oil Pressure Sensor | |
The transmission lube oil pressure sensor is an input to the ECM. The sensor is located in the lube valve manifold. The sensor provides an input signal to the ECM and the signal is also sent to the VIMS. Then, the VIMS informs the operator about the pressure of the transmission lube pressure. The sensor connects to the ECM through contacts J1-11, J1-12 and J1-24.
Transmission Oil Temperature Sensor And Torque Converter Oil Temperature Sensor
| |
| Illustration 7 | g00581765 |
|
Transmission Oil Temperature Sensor | |
The transmission oil temperature sensor is an input to the ECM. The transmission oil temperature sensor is located in the lube valve manifold. The sensor provides an input signal to the ECM and the signal is also sent to the VIMS. Then, the VIMS informs the operator about the temperature of the transmission lube supply. The sensor connects to the ECM through contacts J1-11, J1-12 and J1-52.
The torque converter oil temperature sensor is an input to the ECM. The information from the torque converter oil temperature sensor is sent to the VIMS. The VIMS informs the operator about the temperature of the torque converter oil temperature. The sensor connects to the ECM through contacts J1-11, J1-12 and J1-51.