DTC code
P0238
Turbocharger/Supercharger Boost Sensor A Circuit High
Technical guide
Symptoms
- Stored trouble code and an illuminated warning light
- significant engine power loss
- vehicle entering fail-safe/limp mode until repairs are completed
- possible turbocharger noises (whistling, knocking, grinding, hissing)
- engine misfiring or detonation across cylinders
- inlet ducting rupture under excessive boost pressure
Probable causes
- Damaged or corroded wiring/connectors
- faulty MAP or boost control sensor
- damaged
- split
- dislodged
- hardened
- or perished vacuum lines
- defective vacuum actuator or check valves
- waste gate mechanism mechanical failure
- clogged catalytic converter or muffler restricting exhaust flow
- PCM failure (rare)
Diagnostic steps
- Record all fault codes and freeze frame data.
- Check wiring, connectors, and vacuum lines for damage.
- Verify reference voltage (4.5–4.9V) and sensor resistance.
- Command wastegate actuator open/closed; compare readings to manufacturer specifications.
- Test actuator control rod adjustment and movement.
- Clear codes and complete a full drive cycle.
- If unresolved, suspect turbocharger mechanical failure requiring replacement.
Cross-checked technical synthesis (QA). It does not replace the manufacturer's procedure.
AI here is a librarian: this page shows only what mechanics confirmed, or says “unknown”. It never suggests a diagnosis — MECCANIC interprets the code, never your car.
0 confirmed cases on P0238
Nothing confirmed yet for this code. No guess is offered on purpose.
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