Pressure control solenoid A sticking due to worn, dirty or contaminated fluid; Faulty pressure control solenoid A (mechanical or electrical failure); Blocked or clogged transmission filter or restricted valve body passages; Wiring or connector fault between the solenoid and the control module (chafing, corrosion, short or open circuit); Worn or sticking valve body or spool valve; Incorrect fluid level or wrong fluid type; Faulty transmission control module or outdated software.

P0747

Pressure Control Solenoid A Stuck On.

Generic
Powertrain
Generic code
High severity

How this code is built

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

What it means

P0747 means the transmission control module has detected that Pressure Control Solenoid A is stuck on, so line pressure is staying high or the solenoid is not responding to commands. The module compares the commanded pressure, the solenoid's electrical feedback and the measured gear ratio or slip against expected values, and sets the code when they do not agree. Which solenoid is 'A' and how it is controlled depends on the transmission fitted.

Symptoms

Harsh or abrupt gear changes
Gearbox stuck in one gear or in limp mode
Delayed or flared shifts
Transmission warning light or malfunction message
Engine flare or slip between gear changes
Poor fuel economy

Possible causes

Pressure control solenoid A sticking due to worn, dirty or contaminated fluidlikely
Faulty pressure control solenoid A (mechanical or electrical failure)likely
Blocked or clogged transmission filter or restricted valve body passagespossible
Wiring or connector fault between the solenoid and the control module (chafing, corrosion, short or open circuit)possible
Worn or sticking valve body or spool valvepossible
Incorrect fluid level or wrong fluid typepossible
Faulty transmission control module or outdated softwarerare

How to diagnose

Read all stored codes and freeze frame data, noting fluid temperature, speed and gear when the fault set, and check for related solenoid or ratio codes
Check transmission fluid level, condition and smell using the correct procedure for the model, as some transmissions are sealed and need specific checking conditions
Inspect the transmission wiring harness and connector for damage, leaks, corrosion and fluid ingress
Check for manufacturer bulletins or software updates relevant to the vehicle and transmission
Measure solenoid resistance and compare with the manufacturer specification
Use live data to compare commanded and actual line pressure and watch solenoid duty cycle against gear selection
Test the wiring for shorts to power, ground and open circuits between the solenoid and the control module
Drop the pan and inspect for metal debris, clutch material and a clogged filter, where the transmission design allows

How to fix

Change the transmission fluid and filter with the correct specification fluid if it is dirty or contaminated
Replace pressure control solenoid A if it is faulty or sticking
Repair or replace damaged wiring and connectors, and replace the harness if fluid has wicked into it
Clean or overhaul the valve body, or replace it if it is worn or sticking
Correct the fluid level and type
Update or replace the transmission control module if a fault is confirmed after all other causes are ruled out

Can I keep driving?

High severity

Avoid driving beyond what is needed to reach a workshop, as high line pressure and harsh engagement can damage clutches and the transmission. If the car is in limp mode or shifting violently, stop driving and have it recovered.

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