DTC Advanced Diagnostics: P0720

DTC P0720:Output Shaft (Countershaft) Speed Sensor Circuit Malfunction

General Description

The output shaft (countershaft) speed sensor is attached to the transmission housing to sense output shaft (countershaft) revolutions. The powertrain control module (PCM) determines the vehicle speed according to the signal from the output shaft (countershaft) speed sensor for the control units. If no signal from the output shaft (countershaft) speed sensor is received for a set time, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status

Execution	Continuous
Sequence	None
Duration	5 seconds or more
DTC Type	Two drive cycles, MIL on
OBD Status	PASSED/FAILED/NOT COMPLETED (STILL TESTING)

Enable Conditions

Condition	Minimum	Maximum
Engine speed [ENGINE SPEED]	4,000 rpm	–
12 volt battery voltage [BATTERY]	10.0 V	–
Other	During fuel cut-off operation for deceleration

[ ]: HDS Parameter

Malfunction Threshold

No signal from the output shaft (countershaft) speed sensor is detected for at least 5 seconds during deceleration with the engine speed [ENGINE SPEED] at 4,000 rpm or less.

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.

	Output shaft (countershaft) speed sensor NC line short to ground
	Output shaft (countershaft) speed sensor NC line open
	Output shaft (countershaft) speed sensor connector disconnection
	Output shaft (countershaft) speed sensor failure
	PCM internal circuit failure

Diagnosis Details

Conditions for setting the DTC

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

Conditions for clearing the DTC

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 or by disconnecting the 12 volt battery.