Turbocharger Boost Sensor A Circuit Malfunction
The P0235 code indicates a malfunction in the turbocharger boost sensor A circuit. This sensor monitors the boost pressure produced by the turbocharger and sends a voltage signal to the engine control module (ECM). When the ECM detects a signal that is out of the expected range or missing, it sets this code. Common causes include a faulty boost pressure sensor, damaged wiring or connectors, a vacuum leak, or a malfunctioning turbocharger. This issue can lead to reduced engine performance, poor fuel economy, and potential damage to the turbocharger if not addressed.
01. Most Common Causes
- Faulty turbocharger boost pressure sensor
- Damaged or corroded wiring/connectors in the sensor circuit
- Vacuum leak in the boost pressure reference line
- Malfunctioning turbocharger or wastegate
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or acceleration
- Poor fuel economy
- Excessive black smoke from exhaust
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for additional codes.
Step 2: Visually inspect the boost sensor and its wiring for damage, corrosion, or loose connections.
Step 3: Test the sensor's voltage and resistance with a multimeter and compare to manufacturer specifications.
Step 4: Check for vacuum leaks in the boost reference line using a smoke machine or by listening for hissing sounds.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause reduced performance and potential turbocharger damage. Short trips to a repair shop are generally acceptable.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on whether the sensor or wiring needs replacement.