Low, dirty or degraded transmission fluid, or wrong fluid type; Pressure control solenoid C sticking or failing electrically; Clogged transmission filter or contaminated valve body passages; Damaged wiring, poor connector contact or corrosion between the solenoid and control unit; Worn valve body, bore wear or internal fluid leaks causing pressure loss; Worn clutch pack or seals served by solenoid C; Faulty transmission control unit or outdated software calibration, where a manufacturer bulletin confirms it.

P0796

Pressure Control Solenoid C Performance/Stuck Off.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
7: AreaTransmission
96: FaultThe specific fault in that area

What it means

P0796 means the transmission control unit has detected that pressure control solenoid C is not performing as commanded, or is stuck off. The control unit compares the commanded line or clutch pressure, or the resulting clutch slip and gear ratio, with what it expects, and sets the code when the two disagree. Which clutch or function solenoid C controls varies by transmission, so the exact effect depends on the model.

Symptoms

Gearbox warning light or engine management light on
Harsh, delayed or flared gear changes
Slipping or engine revs rising without matching acceleration
Transmission stuck in one gear or in limp mode
Failure to select one or more gears
Poor fuel economy or sluggish performance

Possible causes

Low, dirty or degraded transmission fluid, or wrong fluid typelikely
Pressure control solenoid C sticking or failing electricallylikely
Clogged transmission filter or contaminated valve body passageslikely
Damaged wiring, poor connector contact or corrosion between the solenoid and control unitpossible
Worn valve body, bore wear or internal fluid leaks causing pressure losspossible
Worn clutch pack or seals served by solenoid Cpossible
Faulty transmission control unit or outdated software calibration, where a manufacturer bulletin confirms itrare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting gear, temperature and load when the code set
Check the transmission fluid level, condition and smell, following the manufacturer's procedure for the model, as some are sealed units
Inspect the wiring and connectors to the transmission for chafing, fluid ingress, corrosion and loose pins
Measure the solenoid resistance and compare it with the specification for that transmission
Check the live data for commanded versus actual pressure, gear ratio and slip, and look for other transmission codes
Test the solenoid circuit for power, ground and signal integrity at the control unit
Check for any known software updates or technical bulletins for that model and gearbox
If the electrical checks pass, inspect the pan, filter and valve body for debris, wear and metal particles

How to fix

Correct the fluid level or replace degraded fluid and filter with the specified type
Replace the faulty pressure control solenoid C
Repair or replace damaged wiring, terminals or the internal harness connector
Clean or overhaul the valve body, or replace it if the bores are worn
Rebuild the transmission if the clutches or seals are worn
Update or replace the transmission control unit software only where an outdated or faulty calibration is a known cause

Can I keep driving?

Medium severity

Short, gentle driving is usually possible, but the car may slip or go into limp mode, and continued use can damage clutches and the transmission. Get it checked soon and avoid heavy loads or towing until it is.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.