Code No. P0778: Malfunction of Secondary Pressure Solenoid Valve

DIAGNOSTIC FUNCTION

CVT-ECU determines malfunction by detecting the abnormality in the secondary pressure solenoid valve.

JUDGEMENT CRITERIA

Specified amount of current is not flown to the line pressure solenoid valve because of the open or short circuit.

PROBABLE CAUSES

Malfunction of valve body assembly (Faulty secondary pressure solenoid valve)
Damaged wiring harness and connectors
Malfunction of CVT-ECU

DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III data list

Item 35: Secondary pressure solenoid output current
Item 34: Secondary pressure solenoid monitoring current

OK: Check if the output current and monitoring current differ largely.

Q. Is the check result normal?

	Intermittent malfunction

	Go to Step 2.

STEP 2. Check for open circuit and short to earth in SCLS line between the CVT-ECU connector and the CVT assembly connector.

Q. Is the check result normal?

	Go to Step 3.

	Repair the wiring harness.

STEP 3. Secondary pressure solenoid valve single unit check

Refer to

.

Q. Is the check result normal?

	Go to Step 4.

	Replace the valve body assembly.

STEP 4. Symptom recheck after erasing diagnosis code

Q. Is the check result normal?

	Intermittent malfunction

	Replace CVT-ECU.