P2390 indicates the powertrain control module has detected an open circuit in the control circuit for the secondary ("B") diesel intake air flow control actuator or solenoid. This means the expected electrical path to operate the intake air flow control device is broken, so the actuator cannot be commanded properly. The fault may be inside the actuator coil, in the wiring/connectors, or less commonly in the control module output driver.
The actuator coil can fail open internally, creating the exact circuit break the code reports. This is the most common root cause and should be verified before replacing other parts.
A break, pinch, chafe, or corrosion in the wire between the PCM and the actuator interrupts current flow and sets the open-circuit code.
Loose terminals, pushed-out pins, or corrosion at the actuator or harness connector create high resistance or a complete open in the control circuit.
If the actuator shares a fused power feed, a blown fuse or faulty relay can remove operating voltage and mimic a control-circuit open.
Although much less common, the PCM output driver that switches the actuator could fail. This should only be considered after the actuator, wiring, connectors, and power supply have been ruled out.
Short trips are usually possible, but the engine may run poorly, produce excess smoke, or enter limp mode. Prolonged driving is not recommended because emissions and drivability are affected.
Usually no. The actuator itself or its wiring/connectors is the far more likely cause. PCM failure is uncommon for this code and should only be suspected after all other possibilities are eliminated.
The 'B' identifier distinguishes a secondary or parallel intake air flow control system. The diagnostic approach is the same as for 'A', but testing must focus on the specific 'B' actuator circuit and connector.
Not typically. P2390 is an electrical open-circuit fault, not a carbon buildup fault. Cleaning may help other intake-related codes, but it will not repair a broken wire or failed actuator coil.