DTC Advanced Diagnostics: P0777
DTC P0777:CVT Driven Pulley Pressure Control Solenoid Valve Stuck ON

General Description

The CVT driven pulley pressure control solenoid valve controls hydraulic pressure to the driven pulley. The CVT driven pulley pressure control solenoid valve is controlled by duty cycle output. The spool in the CVT driven pulley pressure control solenoid valve moves the valve according to the current, and produces hydraulic pressure in proportion to the current. To shift the transmission properly, the transmission control module (TCM) outputs a driven pulley hydraulic pressure control signal. If the pulley ratio is overdrive while the vehicle is stopped with the forward clutch engaged and belt slippage occurs when driving, the TCM detects a CVT driven pulley pressure control solenoid valve stuck ON failure and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Continuous
Sequence
None
Duration
Depending on the driving conditions
DTC Type
Two drive cycles, MIL on, Shift position indicator blinks

Enable Conditions
Condition
Minimum
Maximum
Engine speed [Engine Speed]
500 rpm
–
Vehicle speed [Vehicle Speed]
–
3 mph (5 km/h)*
–
8 mph (13 km/h)**
Accelerator pedal position
–
2.7 °*
4 °**
–
Shift lever position/mode
D
*: Symptom 1
**: Symptom 2
[ ]: HDS Parameter

Malfunction Threshold
Symptom 1 and Symptom 2 occurs.

Symptom
Vehicle conditions
TCM detection
1
Stopped with forward clutch engaged
Pulley ratio [Pulley Ratio] is more than 0.3, or less than 0.6 for at least 2.5 seconds
2
Running
Pulley ratio [Pulley Ratio] is more than 3.0

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
CVT driven pulley pressure control solenoid valve stuck on

Confirmation Procedure
Operating Condition

1.
Start the engine.
2.
Accelerate the vehicle in D position/mode until the speed reaches 37 mph (60 km/h).
3.
Slow down and stop the vehicle.
4.
Accelerate the vehicle with wide open throttle.
5.
Slow down and stop the vehicle.
6.
Turn the vehicle to the OFF (LOCK) mode.
7.
Repeat Driving Pattern steps 1 through 5.
Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
With the HDS
None.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the TCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on, the shift position indicator blinks, and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The shift position indicator comes off by turning the vehicle to the OFF (LOCK) mode. The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.