P1731

DTC P1731: 1st Engine Brake Detection

DESCRIPTIONS OF MONITOR METHODS
^ With the mode other than SPORT MODE and with the accelerator angle is smaller than 6/8, the correlation between the lock-up and low-reverse brake linear solenoid valve control current and the low-reverse brake pressure switch ON/OFF is abnormal.

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
^ Transaxle assembly powertrain parts failure
^ Malfunction of the valve assembly (Malfunction of hydraulic valve and hydraulic switch)
^ Malfunction of the TCM
^ Malfunction of the lock-up and low-reverse brake linear solenoid valve (valve assembly)
^ Malfunction of the low-reverse brake pressure switch (valve assembly)
^ Malfunction of the low clutch pressure switch (valve assembly)
^ Malfunction of the low clutch linear solenoid valve (valve assembly)
^ Malfunction of the low-reverse brake shift solenoid valve (valve assembly)
^ Malfunction of the low clutch, low-reverse brake

DIAGNOSIS

STEP 1. Check the DTC.
Check that P0841 (Low-clutch pressure switch) and P0988 (Low-reverse brake pressure switch) are set.

Q:Is the DTC set?
YES: Check and repair the relevant DTC system.
NO: Go to Step 2.

STEP 2. Check the DTC.
Check that the DTC other than P1731 (1st engine brake detection) is set.

Q:Is the DTC set?
YES: Check and repair the relevant DTC system.
NO: Go to Step 3.

STEP 3. Check the transmission fluid properties.
Check the status of the transmission fluid properties (smell, color, fouling).

^ Black: A/T inside damage, seizure
^ Milky: Water intrusion

Q:Is the check result normal?
YES: Go to Step 4.
NO: Remove the A/T from the vehicle, then check and repair the inside.

STEP 4. Check the transmission fluid level.

Q:Is the check result normal?
YES: Go to Step 5.
NO: Adjust the transmission fluid level, and then go to Step 5.

STEP 5. Check the wiring harness, connector, and sensor signal.
^ Check the wiring harness and connectors of the low-clutch pressure switch and low-reverse brake pressure switch.
^ Check the signals of C-37 TCM connector terminal No. 37 (output shaft speed sensor) and the terminal No. 38 (input shaft speed sensor).

Q:Is the check result normal?
YES: Go to Step 6.
NO: Repair or replace the failure section.

STEP 6. Hydraulic pressure test

Q:Is the check result normal?
YES: Go to Step 7.
NO: Remove the A/T from the vehicle, then check and repair the inside.

STEP 7. Erase the DTC code, and drive the vehicle for a while.
Check that the normal code is displayed.

Q:Is the check result normal?
YES: The procedure is complete.
NO: Return to START.