P1915 Fuel Tank Pressure Sensor Low Voltage
The P1915 code indicates that the Powertrain Control Module (PCM) has detected an abnormally low voltage signal from the Fuel Tank Pressure (FTP) sensor, also known as the Vapor Pressure Sensor (VFS). This sensor measures pressure or vacuum in the fuel tank to detect leaks in the EVAP system. A 'Failed Low' condition means the signal voltage is below the calibrated minimum threshold (typically less than 0.2V), suggesting an open circuit, short to ground, or internal sensor failure.
01. Most Common Causes
- Faulty Fuel Tank Pressure (FTP/VFS) sensor
- Signal circuit shorted to ground
- 5V reference circuit shorted to ground or open
- Sensor ground circuit open or high resistance
- Damaged, corroded, or loose sensor connector terminals
- Internal PCM failure (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Possible fuel odor or EVAP system leak
03. Step-by-Step Diagnosis
Scan for additional EVAP-related codes and freeze frame data
Visually inspect FTP sensor connector and wiring for damage or corrosion
Measure signal voltage at sensor connector with key on; should be ~0.5-4.5V; if below 0.2V, suspect short or sensor failure
Check 5V reference and ground circuits at sensor connector
If circuits are okay, replace FTP sensor; if code returns, test PCM
1. Frequently Asked Questions
Is it safe to drive?▼
Yes, but the EVAP system may not function properly, potentially causing increased emissions or a fuel smell. Have it diagnosed soon.
How much does it cost to fix?▼
Typically $150-$350 for parts and labor, depending on sensor cost and accessibility.