P0791

U660E AUTOMATIC TRANSAXLE: AUTOMATIC TRANSAXLE SYSTEM: P0791: Intermediate Shaft Speed Sensor "A" Circuit

DTC P0791 - Intermediate Shaft Speed Sensor "A" Circuit

DTC P0793 - Intermediate Shaft Speed Sensor "A"

DESCRIPTION

This sensor detects the rotation speed of the turbine which shows the input speed of transaxle. By comparing the input turbine speed signal (NC) 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 shift.









MONITOR DESCRIPTION

The NT terminal of the TCM detects a revolution signal from the speed sensor (NT) (input RPM). The TCM calculates a gearshift comparing the speed sensor (NT) with the speed sensor (NC).
While the vehicle is operating in 2nd, 3rd, 4th or 5th gear in the shift position of D, if the input shaft revolution is less than 300 rpm *1although the output shaft revolution is more than 1,000 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 31 mph (50 km/h) or more.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS

P0791:





P0793:





WIRING DIAGRAM





INSPECTION PROCEDURE

1. DATA LIST
NOTE:
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.
HINT: Using 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.

(a) Warm up the engine.
(b) Turn the engine switch off.
(c) Connect Techstream to the DLC3.
(d) Turn the engine switch on (IG).
(e) Turn on the tester.
(f) Enter the following items: "Powertrain / ECT / Data List".
(g) According to the display on the tester, read "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 31 mph (50 km/h) or more: Sensor trouble, improper installation, or intermittent connection trouble of the circuit.

PROCEDURE

1. INSPECT SPEED SENSOR (SENSOR INSTALLATION)




(a) 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. CHECK 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:






NG -- REPLACE TRANSMISSION WIRE
OK -- Continue to next step.
3. REPLACE SPEED SENSOR
NEXT -- Continue to next step.
4. CHECK IF DTC OUTPUT RECURS (SEE IF DTC P0791 AND/OR P0793 IS OUTPUT AGAIN)
(a) Connect Techstream to the DLC3.
(b) Start the engine and turn the Techstream main switch ON.
(c) Perform the monitor drive pattern Monitors, Trips, Drive Cycles and Readiness Codes.
(d) When you use Techstream:
Select the item "Powertrain / ECT / Trouble Codes".
(e) Read the DTCs using Techstream.
Result:






B -- END
A -- REPLACE TCM