A340E Automatic Transmission System

A340E AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: P0717: Turbine Speed Sensor Circuit No Signal
P0717 - Turbine Speed Sensor Circuit No Signal

DESCRIPTION

The sensor detects the rotation speed of the turbine which shows the input revolution of the transmission.

By comparing the input turbine speed signal (NCO) with the counter gear speed sensor signal (SP2), the ECM detects the shift timing of the gears and appropriately controls the engine torque and hydraulic pressure according to various conditions. As a result, the gears shift smoothly.





1. Reference (Using an oscilloscope):





Check the waveform between terminals NCO+ and NCO- of the ECM connector.

Standard:

Refer to the illustration.





MONITOR DESCRIPTION

This DTC indicates that a pulse is not output from the speed sensor NCO (Turbine (input) speed sensor) or is weak. The NCO terminal of the ECM detects the pulse signal from speed sensor (NCO) (input RPM). The ECM outputs a gear shift signal comparing the speed sensor (NCO) with the output speed sensor (SP2).

If the input shaft revolution is less than 300 rpm*1 although the output shaft revolution is 500 rpm or more*2, the ECM detects the trouble, illuminates the MIL and stores the DTC.

*1: A pulse is not output or is irregularly output.

*2: The vehicle speed is approximately 50 km/h (31 mph) or more.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





COMPONENT OPERATING RANGE





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Perform the universal trip to clear permanent DTCs DTC Check / Clear.

HINT
According to the Data List displayed by Techstream, you can read the values of switches, sensors, actuators and so on without removing parts. Reading the Data List as the first step of troubleshooting is one method to save time.

NOTICE:
In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.

1. Warm up the engine.

2. Turn the ignition switch off.

3. Connect Techstream to the DLC3.

4. Turn the ignition switch to ON.

5. Turn the Techstream on.

6. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data.

7. According to the display on the tester, read the Data List.

Engine and ECT





HINT
* SPD (NCO) is always 0 while driving indicates:
3rd Gear: Open or short in the sensor or circuit.
4th Gear: Engine speed 0 rpm
* SPD (NCO) is always less than 300 rpm while driving the vehicle at 50 km/h (31 mph) or more indicates:
Sensor trouble, improper installation, or intermittent connection trouble in the circuit.

PROCEDURE

1. INSPECT SPEED SENSOR INSTALLATION

(a) Check the speed sensor (NCO) installation.





OK:

The installation bolt is tightened properly and there is no clearance between the sensor and transmission case.

NG -- REPLACE SPEED SENSOR (NCO) Removal
OK -- Continue to next step.

2. INSPECT SPEED SENSOR (NCO)

(a) Disconnect the speed sensor connector from the transmission.





(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:





NG -- REPLACE SPEED SENSOR (NCO) Removal
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (SPEED SENSOR - ECM)

(a) Connect the speed sensor connector.





(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal