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.


CONSULT 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 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 CONSULT

1.Turn ignition switch "ON". (Do not start engine.)
2.Select "DATA MONITOR" mode for "TRANSMISSION" with CONSULT.
3.Start engine and maintain the following conditions for at least 5 consecutive seconds.
ACCEL POSI: 1/8 or less
VHCL/S SE-AT: 30 km/h (19 MPH) or more
4.If DTC is detected, go to Diagnosis Procedure (see below).


Diagnosis Procedure


1. CHECK CAN COMMUNICATION LINE

Perform the self-diagnosis. Diagnosis System (TCM).
Is malfunction in the CAN communication indicated in the result?
YES- Check CAN communication line.
NO- GO TO 2.

2. CHECK INPUT SIGNAL

With CONSULT
1.Start engine.
2.Select "ECU INPUT SIGNALS" in "DATA MONITOR" mode for "TRANSMISSION" with CONSULT.
3.Drive vehicle and read out the value of "VHCL/S SE-MTR".
OK or NG
OK- GO TO 4.
NG- GO TO 3.

3. CHECK COMBINATION METERS

Check combination meters. Component Description.
OK or NG
OK- GO TO 4.
NG- Repair or replace damaged parts.

4. CHECK DTC

Perform "DTC Confirmation Procedure".
- .
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. Main Power Supply And Ground Circuit.
OK or NG
OK- GO TO 6.
NG- Repair or replace damaged parts.

6. DETECT MALFUNCTIONING ITEM

Check the following.
- The 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. Service and Repair.
NG- Repair or replace damaged parts.