P1774
P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTIONDescription
^ Low coast brake solenoid valve is turned ON or OFF by the TCM in response to signals sent from the PNP switch, vehicle speed sensor and accelerator pedal position sensor (throttle position sensor). Gears will then be shifted to the optimum position.
^ This is not only caused by electrical malfunction (circuits open or shorted) but also by mechanical malfunction such as control valve sticking, improper solenoid valve operation.
DTC Logic
DTC DETECTION LOGIC
P1774:
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.
1. CHECK DTC DETECTION
With CONSULT-III
1. Start the engine.
2. Select "DATA MONITOR".
3. Drive vehicle and maintain the following conditions.
GEAR: "1" or "2" (LC/B ON/OFF)
MANU MODE SW: ON
4. Stop vehicle.
5. Turn ignition switch OFF, then perform step 1 to 3 again.
With GST
Follow the procedure "With CONSULT-III".
Is "P1774 LC/B SOLENOID FNCT" detected?
YES >> Go to TM-162, "Diagnosis Procedure".
NO >> Check Intermittent incident. Refer to, "Intermittent Incident". Testing and Inspection
Diagnosis Procedure
1. CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to, "Diagnosis Procedure".
Is the inspection result normal?
YES >> Replace the control valve with TCM.
NO >> Repair or replace damaged parts.