DTC Advanced Diagnostics: P0723

DTC P0723 : Countershaft Speed Sensor Intermittent

General Description

Courtesy of HONDA, U.S.A., INC.

Courtesy of HONDA, U.S.A., INC.

The countershaft speed sensor is attached to the outside of the transmission housing. The countershaft speed sensor generates different frequency pulse signal depending on the rotating speed of the countershaft driven gear. The pulse signal is transmitted to the transmission control module (TCM) and used for measurement of the countershaft speed. When there is a missing pulse while the countershaft is rotating which occurs by open circuit, intermittent open circuit, and short circuit, the TCM detects as a malfunction. If the rotation speed measured by the countershaft speed sensor fluctuates for a specified time within a specified period, the TCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type

Execution	Continuous
Sequence	None
Duration	Within 2 seconds
DTC Type	Two drive cycles, MIL on, shift position indicator blinks

Enable Conditions

Condition		Minimum	Maximum
Vehicle speed [Vehicle Speed]		13 mph (21 km/h)	-
Other		Not while shifting

[ ]:HDS Parameter

Malfunction Threshold

The rotation speed measured by the countershaft speed sensor fluctuates +/-290 rpm or more in 10 milliseconds, and the abnormal fluctuation occurs at least ten times within 2 seconds.

Possible Cause

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.

Countershaft speed sensor intermittent failure
Countershaft speed sensor NC line intermittent open (includes a loose or disconnected connector)
Countershaft speed sensor VCC3 line intermittent open (includes a loose or disconnected connector)
Countershaft speed sensor SG3 line intermittent open (includes a loose or disconnected connector)
Countershaft speed sensor NC line intermittent short to ground
TCM internal circuit failure

Confirmation Procedure

Operating Condition

Start the engine.
Test-drive the vehicle from 1st gear to 10th gear at speeds over 13 mph (21 km/h).

Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

Diagnosis Details

Conditions for setting the DTC

When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the TCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on, the shift position indicator blinks, and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC

The shift position indicator comes off by turning the vehicle to the OFF (LOCK) mode. The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool clear command.