P1731
DTC P1731 A/T 1ST ENGINE BRAKINGDescription
Fail-safe function to prevent sudden decrease in speed by engine brake other than at M1 position.
CONSULT-II Reference Value
On Board Diagnosis Logic
^ This is not an OBD-II self-diagnostic item.
^ Diagnostic trouble code "A/T 1ST E/BRAKING" with CONSULT-II or 13th judgement flicker without CONSULT-II 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 1st gear acts other than at M1 position.
Possible Cause
^ Harness or connectors
(The sensor circuit is open or shorted.)
^ Low coast brake solenoid valve
^ ATF pressure switch 2
DTC Confirmation Procedure
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 "DATA MONITOR" mode for "A/T" with CONSULT-II.
3. Start engine.
4. Drive vehicle and maintain the following conditions for at least 2 consecutive seconds.
ENGINE SPEED: 1,200 rpm
Selector lever: "M" position
Gear position: 1st gear
5. If DTC is detected, go to "Diagnostic Procedure".
Diagnostic Procedure
1. INPUT SIGNALS (WITH CONSULT-II)
With CONSULT-II
1. Start the engine.
2. Select "ECU INPUT SIGNALS" or "MAIN SIGNALS" in "DATA MONITOR" mode for "A/T" with CONSULT-II.
3. Drive vehicle in the "M" position (1st gear), and confirm the ON/ OFF actuation of the "ATF PRES SW 2".
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2. CHECK TCM
Perform TCM input/output signal inspection.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING ITEM
Check the following items:
^ Power supply and ground circuit for TCM.
^ The A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the transmission assembly.
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform DTC Confirmation Procedure.
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.