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OBD-II Code

P0045

Severity

Not yet reviewed

Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.

Can you drive it

We cannot say

Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.

Indicative cost (USD)

$80–$2,500

From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.

P0045 sets when the ECU detects a generic circuit fault on the turbo/super charger boost control 'A' actuator solenoid - the PWM solenoid that meters vacuum or boost pressure to the wastegate diaphragm (on traditional wastegate systems) or controls the variable-vane actuator (on VGT turbos).

How a shop works this

Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.

  1. Note every code that is set, not just this one.

    Codes that appear together usually narrow the cause faster than any one of them read alone.

  2. Read the freeze frame — the conditions the fault was recorded under.

    Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.

  3. Confirm the fault is current rather than history.

    Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.

  4. Then follow the diagnostic notes further down this page, in the order they are written.

    They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.

If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.

Common symptoms

  • Check engine light
Read the full diagnostic procedureP0045 sets when the ECU detects a generic circuit fault on the turbo/super charger boost control 'A' actuator solenoid - the PWM solenoid that meters…

P0045 sets when the ECU detects a generic circuit fault on the turbo/super charger boost control 'A' actuator solenoid - the PWM solenoid that meters vacuum or boost pressure to the wastegate diaphragm (on traditional wastegate systems) or controls the variable-vane actuator (on VGT turbos). When the PCM commands the solenoid and the resulting boost behavior or current feedback doesn't match expectation, P0045 fires.

Cheapest-first ladder

  1. Locate the boost-control solenoid (typically a small valve with two vacuum lines and a 2-pin electrical connector, mounted on the firewall or near the turbo) and inspect both vacuum lines for cracks, kinks, or oil intrusion - blown vacuum hoses are the dominant root cause and a $5 length of hose closes a meaningful percentage of these codes.
  2. DMM the solenoid resistance pin-to-pin - typical 25-50 ohms; open or shorted readings confirm internal solenoid failure.
  3. Bidirectional-command the solenoid with a scan tool and verify it clicks and that vacuum/boost passes through when commanded - a stuck-closed solenoid will set this code even with healthy electrical readings.
  4. Inspect the wastegate actuator diaphragm for tears. Expensive-misdiagnosis trap: turbocharger replacement on P0045 when a $40 solenoid or a $5 vacuum hose was the actual fix.
Vehicle-specific patterns2004-2010 VW / Audi 1.8T and 2.0T (early) throws P0045 from a failed N75 boost-control valve - a near-universal failure component on these engines.
  • 2004-2010VW / Audi 1.8T and 2.0T (early) throws P0045 from a failed N75 boost-control valve - a near-universal failure component on these engines.
  • 2007-2013GMC / Chevy 2500HD with the 6.6L Duramax LMM / LBZ throws P0045 from a failed VGT vane actuator or oil-coked vanes - GM TSB coverage exists for VGT cleaning service.
  • 2008-2014Subaru WRX EJ255 throws P0045 from a failed boost control solenoid (the 'BCS' in Subaru tuner parlance).
  • 2010-2016Ford F-250 / F-350 with the 6.7L Power Stroke diesel throws P0045 from a failed VGT actuator.

Estimated repair$80 to $2,500

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