Turbo Boost Pressure Sensor Circuit Bank 1 Low (Generic)
The P4045 code means the vehicle's onboard diagnostic system has detected: Turbo Boost Pressure Sensor Circuit Bank 1 Low (Generic). This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $80 - $350 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Reduced turbo boost pressure
- Sluggish acceleration
- Lower than expected power output
- Turbo may overboost uncontrolled
Probable Causes (Ranked by Likelihood)
- Short to ground in boost sensor circuit Very High
- Boost pressure sensor reading low High
- Boost pressure reference tube leak Moderate
- Corroded sensor connector Low
Step-by-Step Diagnostic Procedure
-
Check sensor signal voltage at idle and under boost
-
Inspect reference tube from intake to sensor for leaks
-
Test for shorts to ground in wiring
-
Verify sensor reading matches actual boost with gauge
Frequently Asked Questions
Can a low boost reading cause overboost?
Yes, if the sensor reads low, the PCM may command more wastegate closing to build boost, potentially causing an overboost condition.
Can I drive with P4045?
You can drive short distances at reduced power. Avoid heavy acceleration or towing.
Can a leaking reference tube cause P4045?
Yes, the tube connecting the intake manifold to the boost sensor can develop leaks.
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