P1721

P1721 Vehicle Speed Signal

Description
The vehicle speed signal is transmitted from combination meter 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.

SDT Reference Value in Data List Mode





On Board Diagnosis Logic
^ This is not an OBD-II self-diagnostic item.
^ Diagnostic trouble code "P1721" with SDT is detected when TCM does not receive the proper vehicle speed signal (input by CAN communication) from combination meter.

Possible Cause
Harness or connectors
(The 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 SDT
1. Turn ignition switch "ON". (Do not start engine.)
2. Select "Data list" mode for "AT" with SDT.
3. Start engine and maintain the following conditions for at least 5 consecutive seconds.
ACCELE POSI: 1/8 or less
VHCL/S SE-A/T: 30 km/h (19 MPH) or more
4. If DTC is detected, go to [P1721 Vehicle Speed Signal].

Diagnosis Procedure

Step 1-6: