P1731

P1731 1ST ENGINE BRAKING





Description
Fail-safe function to prevent sudden decrease in speed by engine brake other than at M1 position.




CONSULT-III Reference Value in Data Monitor Mode









On Board Diagnosis Logic
- This is not an OBD-II self-diagnostic item.
- Diagnostic trouble code "P1731" with CONSULT-III or 13th judgment flicker without CONSULT-III is detected under the following conditions.
- When TCM does not receive the proper voltage signal from the sensor.
- When TCM monitors each ATF pressure switch and solenoid monitor value, and detects as irregular when engine brake of 1GR acts other than at M1 position.




Possible Cause
- Harness or connectors
(Sensor circuit is open or shorted.)
- Low coast brake solenoid valve
- ATF pressure switch 2




DTC Confirmation Procedure

CAUTION:
- Always drive vehicle at a safe speed.
- Be careful not to rev engine into the red zone on the tachometer.

NOTE:
If "DTC Confirmation Procedure" has been previously preformed, 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 2 consecutive seconds.

ENGINE SPEED: 1,200 rpm
MANU MODE SW: ON
GEAR: "1" position

4. If DTC is detected, go to P1731.




Diagnosis Procedure
1.CHECK INPUT SIGNALS
With CONSULT-III
1. Start engine.
2. Select "DATA MONITOR" in "TRANSMISSION".
3. Drive vehicle in the "M" position (1GR), and confirm the ON/OFF actuation of "ATF PRES SW 2" and "ON
OFF SOL". P1731.
OK or NG
OK - GO TO 4.
NG - GO TO 2.
2.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 3.
NG - Repair or replace damaged parts.
3.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. Service and Repair.
NG - Repair or replace damaged parts.
4.CHECK DTC
Perform P1731.
OK or NG
OK - INSPECTION END
NG - GO TO 2.