Nissan Maxima Service and Repair Manual: P1723 speed sensor
The secondary speed sensor detects the revolution of parking gear and generates a pulse signal. The pulse signal is sent to the TCM, which converts it into vehicle speed.
The primary speed sensor detects the primary pulley revolution speed and sends a signal to the TCM.
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
CAUTION: Always drive vehicle at a safe speed.
NOTE: Immediately after performing any "DTC CONFIRMATION PROCEDURE", always turn ignition switch OFF.
Then wait at least 10 seconds before performing the next test.
1.CHECK DTC DETECTION
Turn ignition switch ON.
Select "Data Monitor" in "TRANSMISSION".
Start engine and maintain the following conditions for at least 5 consecutive seconds.
VEHICLE SPEED : 10 km/h (6 MPH) or more
ACC PEDAL OPEN : More than 1.0/8
RANGE : "D" position
ENG SPEED : 450 rpm or more
Driving location : Driving the vehicle uphill (increased engine load) will help maintain the driving conditions required for this test.
1.CHECK STEP MOTOR FUNCTION
Perform "Self Diagnostic Results" in "TRANSMISSION".
2.CHECK SECONDARY SPEED SENSOR SYSTEM
Check secondary speed sensor system. Refer to TM-60, "DTC Logic".
3.CHECK PRIMARY SPEED SENSOR SYSTEM
Check primary speed sensor system. Refer to TM-57, "DTC Logic".
4.CHECK ENGINE SPEED SIGNAL SYSTEM
Check engine speed signal system. Refer to TM-64, "DTC Logic".
5.DETECT MALFUNCTIONING ITEMS
Check TCM connector pin terminals for damage or loose connection with harness connector.