P0778

DTC P0778 Pressure Control Solenoid "B" Electrical (Shift Solenoid Valve SL2)

DESCRIPTION
Shifting from 1st to 5th is performed in combination with the ON and OFF operation of the shift solenoid valves SL1, SL2, S1, S2, S3, S4 and SR, which are controlled by the ECM. If an open or short circuit occurs in the shift solenoid valves, the ECM controls the remaining normal shift solenoid valve to allow the vehicle to be operated safely.

P0778:

1. Reference: Inspect using an oscilloscope. Check the waveform of the ECM connector.
OK: Refer to illustration.

MONITOR DESCRIPTION
This DTC indicates an open or short in the shift solenoid valve SL2 circuit. The ECM commands gear shifts by turning the shift solenoid valves ON/OFF. When there is an open or short circuit in any shift solenoid valve circuit, the ECM detects the problem, illuminates the MIL and stores the DTC. Also, the ECM performs the fail-safe function and turns the other shift solenoid valves in good condition ON/OFF. In case of an open or short circuit, the ECM stops sending the current to the open or short circuited solenoid. While driving and shifting gears, if the ECM detects an open or short in the shift solenoid valve SL2 circuit, the ECM determines there is a malfunction.

MONITOR STRATEGY