What it means
The control module monitors the electrical circuit for pressure control solenoid A. It sets this code when the circuit signal is intermittent or erratic rather than consistently present.
At a glance
- Usually lights the check-engine light
How it works
Pressure control solenoid A changes hydraulic flow in response to commands from the transmission module. P0749 indicates that the module sees solenoid A’s electrical signal come and go or behave erratically rather than remain consistent. A loose connection, vibration-sensitive harness fault, or failing solenoid can make shifts unpredictable.
Common causes
Most likely first.
- Intermittent contact at connector
- Connector with intermittent contact under vibration
- Harness routed against vibrating component
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Record freeze-frame data and note whether P0749 appears with particular gears, road conditions, or vibration, then review solenoid A live data.
- Inspect solenoid A’s connector for loose fit, corrosion, fluid intrusion, or terminals that may lose contact.
- Trace the harness for chafing, poor support, or contact with vibrating or hot components, especially along the route to the transmission.
- Monitor circuit continuity or the solenoid command while moving the harness and connector as permitted by the manufacturer's procedure.
- If the wiring remains stable, test solenoid A’s coil and operation against the manufacturer's specification.
Common fixes
- Reseat and secure a loose solenoid A connector.
- Clean corrosion or replace damaged terminals in the connector.
- Repair and properly support wiring that is chafed or vibrating against another component.
- Replace solenoid A if it fails electrical checks or remains intermittent with sound wiring.
Can I keep driving?
Limit driving if shifts become unpredictable, harsh, or slipping occurs, and avoid towing or fast traffic where sudden loss of a gear could be hazardous. Continued slip or abnormal shifting can overheat and damage the transmission.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.