Vacuum Reservoir Pressure Sensor Circuit Range/Performance
The P2526 code indicates that the Engine Control Module (ECM) has detected a vacuum reservoir pressure sensor signal that is outside the expected range or performance parameters. This sensor monitors vacuum levels in the reservoir, which is used by various systems like brake boost, HVAC, and emissions. A faulty sensor, wiring issues, or vacuum leaks can trigger this code.
01. Most Common Causes
- Faulty vacuum reservoir pressure sensor
- Open or shorted wiring/connectors to sensor
- Vacuum leak in reservoir or hoses
- Failed ECM (rare)
02. Symptoms You Will Notice
- Check Engine Light on
- Hard brake pedal (loss of power brake assist)
- Poor HVAC performance (defrost/vent issues)
- Rough idle or stalling
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data
Step 2: Visually inspect vacuum hoses and reservoir for cracks/leaks
Step 3: Test sensor voltage and ground at connector with a multimeter
Step 4: Compare sensor reading to actual vacuum with a gauge
Step 5: Replace sensor if readings are out of spec
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended as it can cause loss of power brake assist and affect vehicle control, especially in emergency situations.
How much does it cost to fix?▼
Typically $50-$150 for parts and labor, depending on the sensor location and shop rates.