Power Steering Pressure Sensor Circuit Range/Performance
The P0551 code indicates that the Power Steering Pressure (PSP) sensor circuit is operating outside of its expected range or performance parameters. The PSP sensor monitors hydraulic pressure in the power steering system and sends a signal to the Engine Control Module (ECM). When the ECM detects a voltage signal that is too high, too low, or not changing as expected, it sets this code. This can affect steering assist and engine idle speed control.
01. Most Common Causes
- Faulty power steering pressure sensor
- Damaged or corroded wiring/connectors in the sensor circuit
- Low power steering fluid level or contamination
- Malfunctioning power steering pump or system blockage
02. Symptoms You Will Notice
- Illuminated Check Engine Light
- Hard or stiff steering, especially at low speeds
- Erratic or fluctuating idle speed when turning
- Loss of power steering assist
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for additional codes.
Step 2: Inspect power steering fluid level and condition; top off or replace if necessary.
Step 3: Visually check 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 specifications.
Step 5: If sensor and wiring are okay, test the power steering system pressure to rule out pump or blockage issues.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as it can lead to loss of power steering assist, making the vehicle difficult to steer, especially at low speeds. This poses a safety risk.
How much does it cost to fix?▼
The cost to fix P0551 typically ranges from $50 to $150 for diagnosis and sensor replacement. Labor costs vary by shop, but the sensor itself is relatively inexpensive.