Faulty pressure control solenoid 'B' itself, such as an open or shorted internal coil; Damaged or corroded wiring harness or connector at the solenoid or transmission case; Transmission fluid contamination or degradation causing solenoid sticking or poor electrical contact; Low or incorrect transmission fluid level affecting hydraulic pressure and solenoid performance; Failed transmission control module (TCM) or internal valve body electrical fault; Poor ground connection for the solenoid circuit

DTC codes / P07xx · Transmission / P0775

P0775Pressure Control Solenoid 'B'

Q: What does code P0775 mean?

Pressure Control Solenoid 'B'. P0775 indicates that the transmission control module (TCM) has detected an electrical fault in the circuit for pressure control solenoid 'B', which is used to regulate hydraulic line pressure inside the automatic transmission. The computer monitors the solenoid's commanded current versus the actual current or circuit continuity, and it sets this code when the values fall outside the expected range.

P0775 indicates that the transmission control module (TCM) has detected an electrical fault in the circuit for pressure control solenoid 'B', which is used to regulate hydraulic line pressure inside the automatic transmission. The computer monitors the solenoid's commanded current versus the actual current or circuit continuity, and it sets this code when the values fall outside the expected range.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaTransmission

Symptoms you may notice

Illumination of the check engine light or transmission warning light, often with no other noticeable symptoms
Harsh or delayed gear shifts, especially when engaging drive or reverse
Transmission may enter limp mode, limiting vehicle speed and gear selection
Slipping or flaring during acceleration as line pressure fails to adjust correctly
Erratic shift timing or shuddering during gear changes

Common causes, most likely first

Faulty pressure control solenoid 'B' itself, such as an open or shorted internal coil
Damaged or corroded wiring harness or connector at the solenoid or transmission case
Transmission fluid contamination or degradation causing solenoid sticking or poor electrical contact
Low or incorrect transmission fluid level affecting hydraulic pressure and solenoid performance
Failed transmission control module (TCM) or internal valve body electrical fault
Poor ground connection for the solenoid circuit

How to diagnose and fix it

Check transmission fluid level and condition; top off or replace fluid if contaminated or low
Inspect the solenoid 'B' electrical connector and wiring for corrosion, chafing, or loose pins
Measure the resistance of solenoid 'B' with a multimeter and compare to manufacturer specification
Test the solenoid circuit for short to ground or open circuit using a wiring diagram
If resistance is out of spec, replace pressure control solenoid 'B' and clear the code
If the solenoid and wiring test good, diagnose the TCM and valve body for internal faults
After repair, clear codes and perform a relearn or adaptation drive cycle as required

What P0775 Often Misses

A contaminated or degraded transmission fluid can cause solenoid 'B' to stick or perform poorly without any electrical fault, so fluid condition is a critical first check.
The code can be set by a poor ground connection or a damaged connector pin that only acts up under vibration or temperature changes, so wiggle tests are valuable.
Some vehicles use solenoid 'B' for multiple functions, and a failure may only show up under specific driving conditions, making intermittent diagnosis common.
Replacing the solenoid without addressing contaminated fluid or a damaged harness often leads to a repeat failure, so root-cause electrical and hydraulic checks are essential.
A failing TCM can mimic a solenoid fault by misreporting current or not commanding the solenoid correctly, so module diagnostics should follow solenoid testing.

Can I keep driving with P0775?

If the vehicle drives normally with only the warning light on, you can drive cautiously to a repair shop, but avoid heavy acceleration or towing. If the transmission is in limp mode, slipping, or shifting harshly, stop driving and have it towed to prevent further damage.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.