P0749 indicates the powertrain control module has detected an intermittent electrical fault in the transmission pressure control solenoid control circuit. This solenoid regulates hydraulic line pressure to control shift quality and clutch engagement. An intermittent signal means the circuit is losing connectivity or exceeding expected resistance ranges sporadically rather than continuously.
The solenoid coil or internal contacts can develop an intermittent open or short as temperature changes, causing the circuit to drop in and out.
Corrosion, bent pins, moisture intrusion, or chafed wires in the transmission harness create resistance spikes or momentary opens that set an intermittent code.
Flexing and heat cycles inside the transmission can degrade the internal harness or bulkhead connector, leading to sporadic circuit interruptions.
A loose or corroded ground point for the solenoid circuit can raise voltage drops and trigger intermittent operation under load or vibration.
Although uncommon, an internal fault in the transmission control driver within the control module can produce an intermittent output; this should only be considered after wiring and the solenoid are proven sound.
It is not advisable to continue driving for extended periods. Intermittent pressure control faults can lead to abrupt shifting, clutch damage, or eventual transmission failure.
Generally no. P0749 is an electrical circuit fault; repairs usually involve the solenoid, wiring, or connectors rather than internal mechanical components.
No. Although some repair suggestions point to the PCM, this is almost never the actual cause. The fault is typically a failing solenoid or wiring issue, and the PCM should only be suspected after exhaustive electrical testing.
Not necessarily. This code refers to an intermittent electrical circuit problem, not a hydraulic blockage. While contaminated fluid can contribute, the primary concern is the electrical path and solenoid coil integrity.