P1721

DTC P1721 VEHICLE SPEED SENSOR MTR

Description
The vehicle speed sensor-MTR 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 revolution sensor when it is malfunctioning. The TCM will then use the vehicle speed sensor-MTR 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 VHE SPD SE/CIR-MTR" with CONSULT-III is detected when TCM does not receive the proper vehicle speed sensor MTR 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" mode for "TRANSMISSION" with CONSULT-III.
3. Drive vehicle and maintain the following conditions for at least 5 consecutive seconds.
VHCL/S SE-MTR: 30 km/h (19 MPH) or more
ACCELE POSI: 1.0/8 or less
4. If DTC is detected, go to "Diagnosis Procedure".

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 AT-92, "Diagnosis Procedure without CONSULT-III". Diagnosis Procedure Without Consult-III

Is malfunction in the CAN communication indicated in the result?
YES >> Check CAN communication line. Refer to AT-95. U1000
NO >> GO TO 2.

2.CHECK INPUT SIGNAL

With CONSULT-III
1. Start engine.
2. Select "DATA MONITOR" mode for "TRANSMISSION" with CONSULT-III.
3. Drive vehicle and read out the value of "VHCL/S SE-MTR". Refer to "CONSULT-III Reference Value in Data Monitor Mode".
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 DI-26. Unified Meter and A/C AMP
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. Refer to AT-161. 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.
NG >> Repair or replace damaged parts.