Power Steering Pressure Sensor Circuit Malfunction
The P0550 code indicates a malfunction in the power steering pressure (PSP) sensor circuit. The PSP sensor monitors hydraulic pressure in the power steering system and sends a voltage signal to the PCM. When the signal is out of expected range or missing, the PCM sets this code. Common causes include a faulty PSP sensor, wiring issues (open, short, or corrosion), low power steering fluid, or a failing power steering pump. This can affect steering effort and idle speed control.
1. Most Common Causes
- Faulty power steering pressure sensor
- Damaged or corroded wiring/connectors in the sensor circuit
- Low or contaminated power steering fluid
- Failing power steering pump
2. Symptoms You Will Notice
- Increased steering effort at low speeds
- Check Engine Light illuminated
- Erratic idle or stalling when turning
- Power steering fluid leaks
3. Step-by-Step Diagnosis
Step 1: Scan for codes and verify P0550 is present. Check freeze frame data.
Step 2: Inspect power steering fluid level and condition. Top off or replace if necessary.
Step 3: Visually inspect the PSP sensor wiring and connector for damage, corrosion, or loose connections.
Step 4: Test the PSP sensor signal voltage with a multimeter. Compare to manufacturer specs.
Step 5: If sensor and wiring are okay, test the power steering pump pressure output.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances. The issue can cause increased steering effort and may affect idle control, leading to stalling. Have it diagnosed promptly.
How much does it cost to fix?▼
Typical repair costs range from $50 to $150 for sensor replacement, plus diagnostic fees. If wiring repair or pump replacement is needed, costs can be higher.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.