What this code means
P0797 concerns the CVT clutch pressure control solenoid valve. The valve may be stuck ON.
P0797 concerns the CVT clutch pressure control solenoid valve and a possible stuck-ON condition. The monitored description is forward clutch/reverse brake engagement that finishes too quickly. The operating sequence below uses specifically timed shifts after the stated replacement action.
There are two levels of repetition in this procedure. One describes the repeated shift pattern with the brake pedal pressed. The other describes repeating the engine-start, shifting and vehicle-off operating sequence. Keeping those levels distinct makes the instructions understandable without changing either repetition requirement.
What the vehicle may do
The transmission control module, or TCM, stores this code when forward clutch/reverse brake engagement takes too little time from start to finish. In other words, the monitored engagement finishes too quickly.
Possible fault areas
The procedure identifies the clutch pressure control solenoid valve and calls for replacing the solenoid valve. The engine-start and shifting sequence follows that action.
The shift pattern moves through N and D with the stated minimum waits. The longer wait is associated with N, while the waits after the moves into D have their own minimum value. The brake-pedal condition continues throughout the shifts.
The vehicle-off step closes the operating sequence. The later repeat instruction includes the engine start, the repeated shift pattern and OFF (LOCK). Retain that whole structure rather than merging all of the repeats into a different total.
Diagnostic path
Replace the solenoid valve
Replace the CVT clutch pressure control solenoid valve.
Start the engine and follow the timed shifts
Start the engine. Keep the brake pedal pressed throughout the shifting sequence.
- Shift to N position/mode, then to D position/mode. Wait for at least 1 second.
- Shift back to N position/mode. Wait for at least 2 seconds.
- Shift to D position/mode. Wait for at least 1 second.
Complete this whole shift sequence five times, keeping the brake pedal pressed. The longer wait belongs to N; the waits after shifting to D are at least 1 second each.
Read the shift pattern as an ordered set of position changes and waits. A waiting period belongs to the position just selected, so moving a wait to a different point would describe a different operation. The repeated pattern retains both the stated order and the continuous brake-pedal condition.
Turn the vehicle off
After completing that shifting sequence five times, turn the vehicle to OFF (LOCK) mode.
Repeat the operating sequence
Repeat the engine-start, shifting and vehicle-off sequence five times. Each time, start the engine and keep the brake pedal pressed throughout the shifts. Go from N to D and wait at least 1 second. Return to N and wait at least 2 seconds. Shift to D and wait at least 1 second. Complete this whole shifting sequence five times, then turn the vehicle to OFF (LOCK) mode.
Keep the two repetition instructions distinct: the shifting sequence is completed five times, and the engine-start, shifting and vehicle-off sequence is also repeated five times.
This repetition operates at the level of the whole engine-start, shifting and vehicle-off sequence. Within it, the shift pattern still has its own repetition instruction. Describing those levels separately preserves the procedure without replacing them with a calculated overall count.
Use the HDS data view
The HDS diagnostic tool function for P0797 is AT Data List.
Final check
Retain the brake-pedal condition throughout the shifts, the order N to D to N to D, and all waiting times. The waits in D are at least 1 second; the wait in N is at least 2 seconds. Keep both sets of five repetitions and the OFF (LOCK) step in the procedure. P0797 concerns a forward clutch/reverse brake engagement duration that is too short.
The final record should make the timed pattern, its repetitions and the repeated operating sequence visible as separate instructions. Keep the brake condition, the waits associated with N and D, and OFF (LOCK) in their stated places. Those details are the operating work given for the stored short-engagement-duration condition.
