5AT RE5R05A

P1721 VEHICLE SPEED SIGNAL





Description
The vehicle speed signal is transmitted from unified meter and A/C amp. to TCM by CAN communication line.
The signal functions as an auxiliary device to the output speed sensor when it is malfunctioning. The TCM will then use the vehicle speed signal.




CONSULT-III Reference Value in Data Monitor Mode









On Board Diagnosis Logic
- This is not an OBD-II self-diagnostic item.
- Diagnostic trouble code "P1721" with CONSULT-III is detected when TCM does not receive the proper vehicle speed signal (input by CAN communication) from unified meter and A/C amp.




Possible Cause
Harness or connectors
(Sensor circuit is open or shorted.)




DTC Confirmation Procedure

CAUTION:
Always drive vehicle at a safe speed.

NOTE:
If "DTC Confirmation Procedure" has been previously performed, always turn ignition switch OFF and wait at least 10 seconds before performing the next test.
After the repair, perform the following procedure to confirm the malfunction is eliminated.

WITH CONSULT-III
1. Start the engine.
2. Select "DATA MONITOR" in "TRANSMISSION".
3. Drive vehicle and maintain the following conditions for at least 5 consecutive seconds.

VCHL/S SE-MTR : 30 km/h (19 MPH) or more
ACCELE POSI : 1.0/8 or less

4. If DTC is detected, go to 5AT RE5R05A.




Diagnosis Procedure
1.CHECK CAN COMMUNICATION LINE
With CONSULT-III
- Select "SELF-DIAG RESULTS" mode for "TRANSMISSION" with CONSULT-III.
Without CONSULT-III
- Perform the self-diagnosis. Refer to Reading and Clearing Diagnostic Trouble Codes.
Is malfunction in the CAN communication indicated in the result?
YES - Check CAN communication line. Refer to 5AT RE5R05A 5AT RE5R05A 5AT RE5R05A 5AT RE5R05A.
NO - GO TO 2.
2.CHECK INPUT SIGNAL
With CONSULT-III
1. Start engine.
2. Select "DATA MONITOR" in "TRANSMISSION".
3. Drive vehicle and read out the value of "VHCL/S SE-MTR". Refer to 5AT RE5R05A.
OK or NG
OK - GO TO 4.
NG - GO TO 3.
3.CHECK UNIFIED METER AND A/C AMP
Check unified meter and A/C amp. Refer to System Description.
OK or NG
OK - GO TO 4.
NG - Repair or replace damaged parts.
4.CHECK DTC
Perform 5AT RE5R05A.
OK or NG
OK INSPECTION END
NG - GO TO 5.
5.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to Main Power Supply and Ground Circuit.
OK or NG
OK - GO TO 6.
NG - Repair or replace damaged parts.
6.DETECT MALFUNCTIONING ITEM
Check A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK - Replace the control valve with TCM. Refer to Service and Repair.
NG - Repair or replace damaged parts.