P0194

Symptoms

• Check Engine light on dashboard
• Unstable engine operation at idle, floating speed
• Jerks and dips during acceleration
• Possible starting difficulties, especially when the engine is hot
• The scanner shows chaotic pressure surges in the fuel rail

Causes

• Damage or oxidation of the fuel pressure sensor connector
• Unstable contact in the sensor wiring (broken wire, bad terminal)
• Internal failure of the fuel pressure sensor (unstable sensing element)
• Fuel pressure pulsations due to faulty fuel pump
• Fuel pump strainer is dirty

How to Fix

1. Read codes and monitor fuel rail pressure in real time in various modes
2. Lightly move the sensor wiring harness with the engine running - if the pressure on the scanner “jumps”, the problem is in the wiring
3. Inspect the sensor connector for oxidation or contact damage
4. Check the supply voltage (5V) and the sensor signal under different operating modes
5. Carry out a load test of the fuel pump to eliminate pressure pulsations
6. If the wiring and pump are in good condition, replace the pressure sensor in the fuel rail

Related codes

Error P0194 by Vehicle Brand