Which solenoid is "C" on my transmission?

It varies by transmission. Most modern automatics use at least three pressure control solenoids labeled A, B, and C, but the physical location and function of "C" differs between designs. Check the manufacturer's service data or wiring diagram to confirm which solenoid the code is referring to before you replace anything.

How is P0796 different from P0798?

P0796 is the performance code — the solenoid isn't producing the commanded pressure even though the circuit may test fine. P0798 is the electrical code — an open, short, or resistance fault in the solenoid circuit. P0796 points you toward fluid, valve body, and hydraulic performance; P0798 points you toward the wiring and coil.

Can I fix P0796 with a fluid change?

Sometimes. Low or dirty fluid and varnish-related valve sticking are common causes, and a proper fluid and filter service can restore normal pressure regulation. It's the right first step because it's inexpensive and rules out the most common contributors. If fresh fluid doesn't clear it, the solenoid or valve body is next.

Is it safe to drive with P0796?

You can usually drive short distances, but chronic low or mistimed pressure lets the clutches slip, and slip generates heat that damages the transmission over time. If it's slamming into gear, slipping badly, or has dropped into limp mode, have it looked at before driving further.

OBD-II trouble code

P0796: Pressure Control Solenoid "C" Performance or Stuck Off

The transmission's pressure control solenoid C isn't regulating hydraulic pressure as commanded — it's underperforming or stuck off. Expect harsh, delayed, or slipping shifts, and check fluid before assuming the solenoid has failed.

Quick facts

System: Powertrain
Category: Transmission / Pressure Control
Severity: Medium severity
Drivable: Usually safe to drive short-term
Repair cost range: $150 – $900
DIY difficulty: Shop recommended

What does P0796 mean?

P0796 sets when the transmission control module (TCM) or PCM commands pressure control solenoid "C" to regulate pressure and the solenoid doesn't respond correctly. Where the electrical code for this solenoid (P0798) catches a clear open or short, P0796 is the performance-and-behavior code: the circuit may test fine electrically, but the solenoid isn't producing the pressure the module expects. "Stuck off" means the valve is stuck in its de-energized, open state and won't build the commanded pressure — there's effectively no pressure response.

Pressure control solenoid C is a third pressure-regulating solenoid in the valve body. Many modern automatics use at least three pressure control solenoids (A, B, and C); which physical solenoid is labeled "C" varies by transmission, so it's worth confirming the assignment in the manufacturer's service data. Whatever circuit it controls, when it can't hold the commanded pressure the affected shifts happen at the wrong firmness — usually harsh, delayed, or slipping — and the transmission can run hotter than normal.

As with the other pressure control codes, P0796 doesn't automatically mean the solenoid is dead. Low or dirty fluid, a valve sticking on varnish, a clogged filter, and valve-body wear can all keep the solenoid from reaching its target. A fluid level and condition check comes first, and the code is sometimes solved with a fluid service or valve-body repair rather than a solenoid swap. Left alone, chronic low or mistimed pressure lets the clutches slip, and slip generates heat that shortens transmission life — so diagnose it promptly.

Common causes

Low transmission fluid level
Dirty or degraded transmission fluid causing valve stiction
Pressure control solenoid C sticking on varnish or debris
Worn or contaminated valve body bleeding off pressure
Failed or weak pressure control solenoid C
Restricted transmission filter starving the pump
Internal transmission wear reducing achievable pressure

Symptoms

Check engine light on with P0796 stored
Harsh, delayed, or flaring shifts
Transmission slipping under load
Transmission running hotter than normal
Falling into limp mode in some cases
Reduced fuel economy when the converter or clutches slip

Diagnostic steps

1.Check transmission fluid level and condition first — low or burnt fluid is a common cause and the cheapest to rule out.
2.Confirm in the manufacturer's service data which physical solenoid is labeled "C" for this transmission.
3.Scan for companion transmission codes; a general P0700 confirms the TCM has stored transmission faults.
4.Read line-pressure live data if the transmission supports it, and compare commanded versus actual pressure.
5.Inspect the solenoid connector and harness for corrosion or damage, then resistance-check solenoid C against specification.
6.If the solenoid tests good and fluid is fresh, suspect valve-body wear or contamination bleeding off pressure.

Repair cost

$150 – $900

A transmission fluid and filter service ($150-$350) is the first step and sometimes the whole fix. A pressure control solenoid replacement runs roughly $250-$700 depending on whether it's externally accessible or requires dropping the pan or valve body. Valve-body repair or replacement is the higher end. Diagnosing line pressure properly is worth the labor before replacing internal parts.

Estimate your repair

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Open the Repair Cost Estimator with transmission shift solenoid replacement preselected. Adjust labor rate and vehicle category to fit your situation.

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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.

Related codes

P0797 P0798 P0746 P0868 P0700 P0750