DTC Advanced Diagnostics: P0722

DTC P0722 : Countershaft Speed Sensor No Signal

General Description

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. When the rotation speed measured by the countershaft speed sensor is a specified value for a set time, the TCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type

Execution	Continuous
Sequence	None
Duration	1.5 seconds or more
DTC Type	One drive cycle, MIL on, shift position indicator blinks

Enable Conditions

Condition	Minimum	Maximum
Vehicle speed [Vehicle Speed]	13 mph (21 km/h)	-
Other	Not while shifting
Other	Not when the shift position/mode is being shifted

[ ]:HDS Parameter

Malfunction Threshold

The rotation speed measured by the countershaft speed sensor is less than 7 rpm for at least 1.5 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 failure
Countershaft speed sensor NC line open (includes a loose or disconnected connector)
Countershaft speed sensor VCC3 line open (includes a loose or disconnected connector)
Countershaft speed sensor SG3 line open (includes a loose or disconnected connector)
Countershaft speed sensor NC line short to ground
TCM internal circuit failure

Confirmation Procedure

Operating Condition

Start the engine.
Test-drive the vehicle at speeds over 13 mph (21 km/h) for at least 2 seconds.

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, the MIL comes on, the shift position indicator blinks, and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the TCM memory.

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.