What this code means
P0777 concerns the solenoid valve that controls pressure at the CVT driven pulley. The valve may be stuck ON.
P0777 concerns the CVT driven pulley pressure control solenoid valve and a possible stuck-ON condition. The monitored description combines overdrive at a stop with the forward clutch engaged and belt slippage while driving. Both conditions belong to the code description used here.
The driven pulley valve is the component identified by this procedure. Keep that identity attached to the replacement work and operating sequence. The checks that follow address the particular P0777 condition rather than a general transmission complaint.
What the vehicle may do
The transmission control module, or TCM, stores this code when two monitored conditions occur together. The pulley ratio is in overdrive while the vehicle is stopped with the forward clutch engaged, and belt slippage occurs when driving. Keep both parts of that condition together when interpreting P0777. It is the combination of the stopped-vehicle condition and belt slippage while driving that is described here.
Possible fault areas
The driven pulley pressure control solenoid valve is integrated with the valve body assembly. The procedure's stated repair action is to replace the driven pulley pressure control solenoid valve.
The HDS AT Data List is the function associated with this path. The replacement action concerns the driven pulley pressure control solenoid valve. After that work, the sequence first uses a drive in D to the specified speed and a stop.
The following drive begins from a stop and explicitly uses full throttle in D. It ends with a slowdown and stop as well. The different starting and throttle requirements explain why these are separate stages in the procedure.
Diagnostic path
Open the HDS data view
On the HDS diagnostic tool, use AT Data List. This is the scan-tool function associated with the procedure.
Replace the driven pulley pressure control solenoid valve
Replace the driven pulley pressure control solenoid valve. Keep the component identity clear: P0777 concerns the driven pulley valve, with a possible stuck-ON condition.
Make the first confirmation drive
Start the engine. Test-drive in D position/mode until the vehicle reaches 37 miles per hour (60 kilometers per hour). Then slow down and stop the vehicle. The next drive starts from this stopped condition.
Read this drive as the first operating stage after the stated work. D position/mode, the target speed and the stop at the end belong together. The next stage uses the stopped condition as its starting point and adds the explicit full-throttle instruction.
Make the full-throttle confirmation drive
From a stop, accelerate at full throttle in D position/mode until the vehicle reaches 37 miles per hour (60 kilometers per hour). Slow down and stop the vehicle again. Keep this full-throttle acceleration separate from the first drive, because its starting condition and throttle instruction are explicit parts of the sequence.
The full-throttle instruction belongs to this acceleration from a stop. Keep it with the specified transmission mode and target speed, then follow the slowdown and stop. This preserves the operating condition that distinguishes this stage from the first drive.
Final check
Retain the order of the two drives and both stops. The first drive reaches 37 miles per hour (60 kilometers per hour) in D. The next starts from a stop and reaches the same speed at full throttle in D. Keep the code interpretation tied to both monitored conditions: overdrive at a stop with the forward clutch engaged, together with belt slippage while driving.
The result record should connect the driven pulley valve work to the two operating sequences. Retain both stops and the explicit conditions for the second acceleration. Keep the original combined monitored conditions together when describing why P0777 was the subject of the procedure.
