OBD-II trouble code
P0796: Pressure Control Solenoid "C" Performance or Stuck Off
A pressure solenoid does not decide whether a gear arrives — it decides how hard and how fast. So the complaint is a transmission that still has all its gears and takes them horribly, and whether that means slamming or slipping depends on how this solenoid rests.
Quick facts
- System
- Powertrain
- Category
- Transmission / Pressure Control
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $150 – $1,400
- DIY difficulty
- Shop recommended
What does P0796 mean?
The most useful thing to understand about P0796 is what a pressure control solenoid actually does, because it is not what a shift solenoid does and the symptom is correspondingly different. A shift solenoid routes fluid and determines which elements apply — it decides whether a gear happens. A pressure control solenoid modulates how much pressure reaches a circuit, which determines how firmly and how quickly a clutch takes hold. So a failing pressure solenoid does not usually take a gear away. It leaves every gear available and makes the transition into them wrong. When an owner says the transmission still gets all its gears, it just does it horribly, that sentence is worth more than the code number.
The letter matters here in a way that is worth stating plainly. The generic range names three pressure control solenoids, A, B and C. A transmission that reports a third one is not regulating a single global line pressure with a helper or two; it has multiple independently controlled pressure circuits, which is the signature of a design where individual clutch apply pressures are managed separately. That gives the diagnosis something to work with: only the shifts that use this solenoid's circuit will be affected. Which shifts feel wrong therefore localises the clutch, and that is a real narrowing rather than a general transmission complaint.
Stuck off is the hydraulic verdict — the electrical side responded and the pressure did not follow. And here is the point that most changes what you should expect to feel, because it is the one thing about this code that reverses depending on the design. Pressure control solenoids come in normally-high and normally-low types. A normally-high solenoid de-energised delivers maximum pressure, so stuck off means the clutches slam home and every affected shift is violently harsh. A normally-low solenoid de-energised delivers minimum pressure, so stuck off means there is not enough pressure to hold the clutch and the affected shifts slip and flare. Identical code, opposite symptoms, and only the service data resolves which one your transmission uses. Diagnosing without knowing that is diagnosing blind.
As with the rest of the family, the code does not by itself condemn the solenoid. Low fluid, a clogging filter, varnish on a spool and a worn valve body bore all prevent commanded pressure from being achieved with a perfectly serviceable solenoid in place. What settles it is a pressure gauge on the test port: compare what was commanded against what was delivered, and the gap tells you whether the control side or the hydraulic side is failing.
Common causes
- Low transmission fluid level, so commanded pressure is never achievable
- Contaminated or degraded fluid leaving varnish on the valve body
- Pressure control solenoid C spool sticking in its bore
- Worn valve body bore bleeding off pressure instead of holding it
- Weak or failed pressure control solenoid unable to regulate accurately
- Restricted filter starving the pump under demand
- Worn pump unable to supply the pressure the circuit needs
- Internal leakage at a seal or sealing ring in the circuit this solenoid feeds
- Adaptive pressure values never reset after previous transmission work
Symptoms
- Every gear still available but the shifts into some of them feeling wrong
- Harsh, slamming shifts on a normally-high design, or slipping and flaring on a normally-low one
- Only certain shifts affected while others feel completely normal
- Transmission running hotter than usual
- Slipping under load, particularly on a gradient or when towing
- Limp mode in some cases, holding a fixed ratio
- Check engine light with P0796 stored, often with P0700 alongside
- Fuel economy falling because the clutches or converter are slipping
Diagnostic steps
- 1.Establish which way the symptom points before touching anything — harsh or slipping. Look up whether this transmission's pressure control solenoids are normally high or normally low, because the same code produces opposite symptoms on the two designs.
- 2.Check fluid level and condition using the manufacturer's procedure and temperature.
- 3.Confirm in service data which physical solenoid this transmission labels C and which circuit it feeds.
- 4.Note precisely which shifts are affected and which are not. On a transmission with independently controlled pressure circuits, that pattern identifies the clutch involved.
- 5.Read commanded versus actual pressure in live data if the transmission reports it, and note the size and direction of the gap.
- 6.Fit a mechanical pressure gauge at the test port and verify actual line and circuit pressure against specification through the affected shifts. This is the measurement that separates a control fault from a hydraulic one and it should not be skipped.
- 7.Inspect the connector and harness, then resistance-check the solenoid, so a marginal circuit is not quietly masquerading as a hydraulic fault.
- 8.Command the solenoid across its range with a scan tool and watch whether pressure follows. No pressure response to a good electrical command confirms the fault is downstream of the coil.
- 9.Drop the pan and inspect the fluid and magnet. Debris or friction material changes the estimate materially and should be established before parts are ordered.
Repair cost
$150 – $1,400
A fluid and filter service is $150 to $350 and is a legitimate first step because contamination genuinely prevents accurate pressure regulation. A pressure control solenoid is $250 to $700 fitted depending on access. A valve body is $600 to $1,400. If a gauge shows the circuit cannot reach commanded pressure even with the solenoid removed from the equation, the conversation moves toward the pump or internal leakage and toward overhaul money — but that finding must come from the gauge, not from the code, so ask for the measured pressure before approving anything in the upper half.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with transmission fluid service preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
Leave this one to a qualified shop. It typically involves emissions-critical components, refrigerant handling, or other work that requires manufacturer-grade tooling, training, or certification. DIY attempts often produce a more expensive problem than the original code.