OBD-II · Engine and powertrain (P)
P0045
Turbo boost control A circuit/open
What it means
This is the circuit that controls the turbo - a boost control solenoid on vacuum-operated turbos, or an electronic actuator on others. The engine computer sees an open circuit.
Symptoms
- loss of power (limp mode)
- engine warning light
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | failed boost control solenoid or actuator |
| 02 | unplugged or corroded connector |
| 03 | broken wiring |
| 04 | blown fuse / no supply |
What to check, step by step
- 01Inspect the connector at the solenoid or actuator for corrosion and oil.
- 02Measure solenoid/actuator resistance against specification.
- 03Check supply voltage and wiring continuity to the engine computer.
- 04Run the actuator test and watch for movement.
- 05Replace the faulty solenoid or actuator; some electronic actuators must be calibrated after fitting.