Fuel Shutoff Valve B Ctrl Circ Low
When this code is stored, it indicates that an open circuit in the fuel shutoff valve system has been detected by the PCM.
In this case, the "B" refers to a particular component, circuit, or area of a particular circuit. Consult the manufacturer's service manual for the exact location of this particular control circuit.
Code Set Parameters
Fuel shutoff valve circuitry parameters are displayed as "open" or "closed". A closed circuit is normal. An open circuit is the equivalent of disconnected or shorted wire and will cause a trouble code to be stored.
A trouble code will be stored and the malfunction indicator lamp will be illuminated. This may or may be accompanied by a no-start condition, depending upon the vehicle application.
The most common cause of this malfunction is a fuel shutoff valve that has been deactivated due to a rear collision. If this is not the case, inspect system electrical wiring and connectors for an open condition.
Inspect the fuel delivery shutoff valve to ensure that it has not been deactivated. Often the fuel pump or other fuel system components are replaced in error due to a lack of fuel pressure at the fuel rail, even when this code has been stored.
- This code is more likely the cause of a lack of fuel pressure rather than a reaction to it
- Test the wiring and connectors at the fuel shutoff valve to make sure that voltage and ground readings are near battery voltage
- Inspect electrical connectors for loose or damaged connectors or wiring
- Corroded connectors, at or near the fuel shutoff valve, frequently test appropriately until the circuit is loaded, at which time the circuit is compromised due to excessive resistance
Several tools will be instrumental in successfully diagnosing this code
- A suitable OBD-II scanner (or code reader), a digital volt/ohmmeter, and an oscilloscope will be most helpful in performing a successful diagnosis
- A manufacturer's service manual (or the equivalent) will also be necessary
Begin with a visual inspection of all wiring and connectors
- Repair or replace damaged, disconnected, shorted, or corroded wiring, connectors, and components as necessary
- Always retest the system after repairs are completed to ensure success.
If all system wiring, connectors, and components (Including fuses) appear to be in normal working order, connect the scanner (or code reader) to the diagnostic connector and record all stored codes and freeze frame data
- This information can be extremely helpful in diagnosing intermittent conditions that may have contributed to this code being stored
- Continue by clearing the code and operating the vehicle to see if it returns
- This will help to determine whether or not the malfunction is intermittent
After the codes are cleared, test drive the vehicle to see if the code returns
- If the code fails to immediately return, you may have an intermittent condition
- Intermittent conditions can prove to be quite a challenge to diagnose and in extreme cases may have to be allowed to worsen before a correct diagnosis can be made.
If the fuel shutoff valve has not been deactivated by a collision, use the digital volt/ohmmeter to test voltage and ground signals at the valve itself
- If voltage and ground signals do not comply with manufacturer's recommendations (and all fuses and relays have been tested and passed) disconnect the fuel shutoff valve connector and all related control module connectors, then perform a continuity and resistance test on all related circuits
- Repair or replace circuitry, connectors, and/or components as required
- Clear the codes and test drive the vehicle to ensure that a successful repair has been performed
If the fuel shutoff switch and all system circuitry checks out, suspect a defective PCM (or other related controller)
- Controller failure is rare and will require reprogramming.