Turbo/Supercharger Boost Control Circuit High
The P0048 code indicates that the Powertrain Control Module (PCM) has detected a high voltage signal from the turbocharger or supercharger boost control solenoid circuit. This solenoid regulates boost pressure by controlling vacuum or pressure to the wastegate actuator. A high voltage condition typically points to a short to power, faulty solenoid, or wiring issues. This can lead to overboost, reduced engine performance, and potential engine damage if not addressed.
01. Most Common Causes
- Short to power in the boost control solenoid circuit
- Faulty turbocharger/supercharger boost control solenoid
- Damaged wiring or connector issues
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Excessive boost pressure (overboost)
- Poor fuel economy
- Engine hesitation or surging
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the boost control solenoid and wiring for damage or corrosion.
Step 3: Test the solenoid resistance with a multimeter (compare to specs).
Step 4: Check for voltage at the solenoid connector with key on (should be battery voltage on one pin).
Step 5: If voltage is present, command the solenoid on/off with a scan tool and listen for clicking.
Step 6: If no click, replace the solenoid. If click, check for short to power in the control circuit.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with P0048 can cause overboost, potentially damaging the turbo or engine. Limp mode may limit speed, but continued driving risks costly repairs.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, including parts and labor. A boost control solenoid costs $50-$150, and labor adds $100-$250 depending on vehicle accessibility.