P1721
DTC P1721 VEHICLE SPEED SENSORDescription
Vehicle speed sensor MTR signal is transmitted from combination meter to TCM by CAN communication line. The signal functions as an auxiliary device to revolution sensor when it is malfunctioning. TCM will then use vehicle speed sensor MTR signal.
CONSULT-II Reference Value
On Board Diagnosis Logic
- This is not an OBD-II self-diagnostic item.
- Diagnostic trouble code "P1721 VHE SPD SE/CIR MTR" with CONSULT-II is detected when TCM does not receive the proper vehicle speed sensor MTR signal (input by CAN communication) from combination meter.
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-II
1. Turn ignition switch "ON". (Do not start engine.)
2. Select "ECU INPUT SIGNALS" in "DATA MONITOR" mode for "A/T" with CONSULT-II.
3. Start engine and maintain the following conditions for at least 5 consecutive seconds.
ACCELE POSI: 1/8 or less
VHCL SPEED SE: 30 km/h (17 MPH) or more
4. If DTC is detected, go to AT-147, "Diagnostic Procedure".
Diagnostic Procedure
1. CHECK CAN COMMUNICATION LINE
Perform self-diagnosis.
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-II
1. Start engine.
2. Select "ECU INPUT SIGNALS" in "DATA MONITOR" mode for "A/T" with CONSULT-II.
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. Refer to "Trouble Diagnosis".
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
N(] >> GO TO 5.
5. CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM 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.
- A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace control valve with TCM.
NG >> Repair or replace damaged parts.