DTC P0793: Intermediate Shaft Speed Sensor "A": Description

WARNING: This page is about a different car, the 2011 Toyota Matrix. However, it is still accessible from the selected car via links, so may be relevant.

This sensor detects the rotation speed of the counter gear. By comparing the counter gear speed signal (NC) with the direct clutch speed sensor signal (NT), the ECM detects the shift timing of the gears and appropriately controls the engine torque and hydraulic pressure according to various conditions. Thus smooth gear shifting is performed.

DTC No.	DTC Detection Condition	Trouble Area
P0793	ECM detects conditions (a), (b) and (c) continuously for 5 sec. or more: (1-trip detection logic) (a) Vehicle speed: 50 km/h (31 mph) or more (b) Park/neutral position switch (NSW) is OFF (c) Speed sensor (NC): less than 300 RPM	Open or short in transmission revolution sensor NC (speed sensor NC) circuit Transmission revolution sensor NC (speed sensor NC) ECM

Reference (Using an oscilloscope):

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

Fig 1: Identifying Intermediate Shaft Speed Sensor "A" Waveform Graph

REFER TO THE ILLUSTRATION:

Terminal	NC+ - NC-
Tool setting	1 V/DIV., 1ms./DIV.
Vehicle condition	Vehicle speed 30 km/h (19 mph): (3rd gear) Engine speed 1,400 RPM