Turbo Bypass Valve Control Circuit High
The P0035 code indicates that the Powertrain Control Module (PCM) has detected a high voltage condition in the control circuit of the turbocharger bypass valve. This valve regulates boost pressure by diverting exhaust gases away from the turbine wheel. A high voltage signal suggests a short to power, open circuit, or faulty component, which can lead to improper boost control and reduced engine performance.
1. Most Common Causes
- Faulty turbocharger bypass valve solenoid
- Short to power in the bypass valve control circuit
- Open or damaged wiring/connectors
- Failed PCM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or boost
- Poor acceleration
- Possible turbocharger overboost or underboost
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P0035 and check for other codes.
Step 2: Visually inspect the bypass valve wiring and connector for damage, corrosion, or loose pins.
Step 3: Test the bypass valve solenoid resistance with a multimeter (specs vary; typically 10-30 ohms).
Step 4: Check for voltage at the solenoid connector with key on; should be battery voltage on one pin. If not, repair open circuit.
Step 5: If wiring and solenoid are good, suspect PCM fault; perform PCM relay and ground checks.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as improper boost control can cause engine damage or reduced performance. Have it diagnosed promptly.
How much does it cost to fix?▼
Typical repair costs range from $50 to $150 for parts and labor, depending on the cause. A bypass valve solenoid replacement is often under $100.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.