Automatic Transmission - U760F
U760F AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSAXLE SYSTEM: P0791,P0793: Intermediate Shaft Speed Sensor "A" Circuit
DESCRIPTION
This sensor detects the rotation speed of the counter gear which shows the output speed of transaxle. By comparing the input turbine speed signal (NT) with the counter gear speed sensor signal (NC), the TCM detects the shift timing of the gears and appropriately controls the engine torque and hydraulic pressure according to various conditions, thus, providing smooth gear shifts.
Text in Illustration
Text in Illustration:
MONITOR DESCRIPTION
The NT terminal of the TCM detects a revolution signal from the speed sensor (NT) (input RPM). The TCM calculates a gear shifts by comparing the speed sensor (NT) with the speed sensor (NC).
While the vehicle is operating in 2nd, 3rd, 4th or 5th gear with the shift lever in D, if the input shaft revolution is less than 300 rpm*1 although the output shaft revolution is more than 1000 rpm*2, the TCM interprets this as a fault, illuminates the MIL and stores the DTC.
*1: Pulse is not output or is irregularly output.
*2: The vehicle speed is 50 km/h (31 mph) or more.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
P0791:
P0791::
P0793:
P0793::
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
Perform the universal trip to clear permanent DTCs .
1. DATA LIST
HINT
Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic 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.
(a) Warm up the engine.
(b) Turn the ignition switch off.
(c) Connect the Techstream to the DLC3.
(d) Turn the ignition switch to ON.
(e) Turn the Techstream on.
(f) Enter the following menus: Powertrain / ECT / Data List.
(g) According to the display on the Techstream, read the Data List.
HINT
- SPD (NC) is always 0 while driving: Open or short in the sensor or circuit.
- SPD (NC) is always more than 0 and less than 300 rpm while driving the vehicle at 50 km/h (31 mph) or more: Sensor trouble, improper installation, or intermittent connection trouble of the circuit.
PROCEDURE
1. INSPECT SPEED SENSOR (SENSOR INSTALLATION)
(a) Remove the valve body assembly.
(b) Make sure that the connector is properly connected, and check the speed sensor installation.
OK:
The installation bolts are tightened properly and there is no clearance between the sensor and transaxle case.
NG -- REPAIR OR REPLACE SPEED SENSOR
OK -- Continue to next step.
2. INSPECT TRANSMISSION WIRE
(a) Remove the TCM.
(b) Disconnect the speed sensor connector from the transmission wire.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
Text in Illustration:
NG -- REPLACE TRANSMISSION WIRE
OK -- Continue to next step.
3. REPLACE SPEED SENSOR
(a) .
NEXT -- Continue to next step.
4. CHECK IF DTC OUTPUT RECURS (SEE IF DTC P0791 AND/OR P0793 IS OUTPUT AGAIN)
(a) Connect the Techstream to the DLC3.
(b) Start the engine and turn the Techstream on.
(c) Enter the following menus: / ECT / DTC / Clear.
HINT
Write down the currently output DTCs before clearing them.
(d) Perform the monitor drive pattern .
(e) Enter the following menus: / ECT / DTC.
(f) Read the DTCs using the Techstream.
Result:
B -- END
A -- REPLACE TCM