P1759
DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTIONDescription
- Front brake solenoid valve operation by the TCM in response to signals sent from the PNP switch, vehicle speed and throttle position sensors. Gears will then be shifted to the optimum position.
- This is not caused by electrical malfunction (circuits open or shorted) but by mechanical malfunction such as control valve sticking, improper solenoid valve operation.
On Board Diagnosis Logic
- This is an OBD-II self-diagnostic item and not available in TCM self-diagnosis.
- Diagnostic trouble code "FR/B SOLENOID FNCT" with CONSULT-II or P1759 without CONSULT-II is detected when TCM detects an improper voltage drop when it tries to operate the solenoid valve.
- When condition of pressure switch 1 is different from monitor value, and relation between gear position and actual gear ratio is abnormal.
Possible Cause
Check the following items.
- Harness or connectors
(The solenoid and switch circuit is open or shorted.)
- Front brake solenoid valve
- Pressure switch 1
DTC Confirmation Procedure
CAUTION: Always drive vehicle at a safe speed.
NOTE:
If "DTC Confirmation Procedure" has been previously conducted, always turn ignition switch "OFF" and wait at least 10 seconds before conducting the next test.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-II
1. Start engine and select "DATA MONITOR" mode for "A/T" with CONSULT-II.
2. Select "FR/B SOLENOID FNCT CHECK" of "DTC WORK SUPPORT" mode for "A/T" with CONSULT-II and touch "START".
3. Accelerate vehicle to maintain the following condition continuously until "TESTING" has turned to "COMPLETE". (It will take approximately 4 seconds after "TESTING" shows.)
ACCELE POS: 1.5/8 - 2.0/8
Selector lever: "D" position
Gear position: 1st - 3rd Gear (FR/B ON/OFF)
Driving location: Driving the vehicle uphill (increased engine load) will help maintain the driving conditions required for this test
4. Make sure that "OK" is displayed. (If "NG" is displayed, refer to "DIAGNOSTIC PROCEDURE".)
Refer to "Diagnostic Procedure".
If DTC (P1757) is detected, go to the Diagnostic Procedure.
If DTC (P1841) is detected, go to the Diagnostic Procedure.
WITH GST
Follow the procedure "With CONSULT-II".
Wiring Diagram-AT-FR/BF
Diagnostic Procedure
1. CHECK VALVE RESISTANCE
1. Turn ignition switch to "OFF" position.
2. Disconnect A/T solenoid valve harness connector 2 at the transmission right side.
3. Check the resistance between terminal 5 and ground.
OK or NG?
OK >>GO TO 2.
NG >> Repair or replace damaged parts.
2. CHECK POWER SOURCE CIRCUIT
1. Turn ignition switch to "OFF" position.
2. Disconnect TCM connector.
3. Check continuity between A/T solenoid valve harness connector 2 and TCM connector.
4. If OK, check harness for short to ground and short to power.
5. Reinstall any part removed.
OK or NG?
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
3. CHECK DTC
Check again.
- Refer to "DTC Confirmation Procedure".
- Refer to "TCM SELF-DIAGNOSTIC PROCEDURE (NO TOOLS)".
OK or NG?
OK >> INSPECTION END
NG >>GO TO 4.
4. CHECK TCM INSPECTION
1. Perform TCM input/output signal inspection.
2. If NG, recheck TCM pin terminals for damage or loose connection with harness connector.
OK or NG?
OK >> INSPECTION END
NG >>
1. Repair or replace damaged parts.
2. Replace the transmission assembly.