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P0197 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.


The low input problem of the fuel rail pressure sensor circuit is referred to in the P0197 DTC code. This code shall be part of OBDII, a system to monitor various aspects of vehicle performance, fuel systems, and emissions on an ongoing basis.


OBDII will trigger a P0197 code when an OBD II system senses that the fuel rail cable sensor circuit is transmitting signals with lower than expected voltage. The fuel rail pressure sensor plays an essential role in providing information to the engine control module ECM about the pressure in the fuel rail.


The P0197 issue code may appear due to a number of possible causes, including the following:

  • Faulty Fuel Rail Pressure Sensor: A malfunctioning or damaged fuel rail pressure sensor can produce low voltage readings or fail to send any data to the ECM.
  • Wiring Issues: Damaged, corroded, or disconnected wiring and connectors associated with the fuel rail pressure sensor can cause low input signals.
  • Issues with the sensor circuit: Shorts or open circuits in the sensor circuit might cause erroneous readings or total sensor failure.
  • ECM Malfunction: On occasion, the engine control module may malfunction, leading to incorrect interpretation of sensor data and activation of the code.


The following signs and symptoms may appear in the car when the P0197 code is present:

  • Check Engine Light: The most noticeable symptom is the illumination of the Check Engine Light on the dashboard.
  • Reduced Engine Performance: Due to inaccurate fuel rail pressure measurements, the engine may have reduced power, rough idling, or reluctance when accelerating.
  • Difficulty Starting: The engine may occasionally struggle to start or take longer to crank.


An experienced mechanic or expert will carry out the following procedures to diagnose the P0197 code:

  • OBD-II Scanner: An OBD-II scanner will be used to retrieve the trouble code and any related codes stored in the system.
  • Visual Inspection: The fuel rail pressure sensor, wiring, and connections will all be examined visually to look for any obvious problems.
  • Testing the Fuel Rail Pressure Sensor: A multimeter will be used to test the voltage and signal of the sensor to see if it functions properly under various engine circumstances.
  • Examining the wire: The technician will carefully look for corrosion or damage in the wire and connections.
  • ECM Testing: If all other parts are in working order, it could be necessary to test or reprogram the ECM.

Common mistakes

Some frequent errors to avoid throughout the diagnostic and repair procedure include:

  • Ignoring Wiring Inspection: By skipping a careful examination of the wiring and connectors, the problem’s underlying cause may go unnoticed.
  • Changing Components Without Proper Testing: In order to prevent unforeseen costs, it is crucial to carry out extensive testing prior to changing any components.

How serious is this?

The seriousness of the P0197 code shall be dependent on the traffic conditions and severity of symptoms. While the vehicle might still be usable, if this is not taken into account it could cause additional problems with engine performance and possible damage.

What repairs can fix the code?

repair manuals

Following diagnosis, the following fixes could be required to fix the P0197 code:

  • Replacing the Fuel Rail Pressure Sensor: A new sensor must be installed if the old one is malfunctioning.
  • Wiring and Connector Repair or Replacement: Damaged parts will need to be repaired or replaced.
  • ECM Reprogramming or Replacement: The ECM could occasionally need to be reprogrammed or replaced.

Related codes

Other related codes that may accompany P0197 include P0190 (Fuel Rail Pressure Sensor Circuit Malfunction), P0191 (Fuel Rail Pressure Sensor Circuit Range/Performance), and P0198 (Fuel Rail Pressure Sensor Circuit High Input).


The DTC code P0197 suggests that there is a possible problem with the fuel rail pressure sensor circuit’s weak input which may affect engine performance. It is important to deal with the problem without delay if you are noticing an illuminated Check Engine Light or experiencing any engine performance problems.

It will help to diagnose and correct this problem, making sure that your vehicle is running effectively and smoothly. If you are in need of expert advice on the issue, seek professional assistance from a certified automobile technician.

P0197 Code – What Does It Mean & How To Fix It