The OBD2 code P0464 indicates an intermittent issue within the fuel level sensor circuit, signaling that the vehicle’s onboard computer (ECM) is receiving erratic data from the sensor that monitors the fuel tank level. This sensor’s role is critical for accurately gauging the amount of fuel in the tank, and any inconsistency can lead to incorrect fuel level readings on the dash, potential stalling, or difficulties in fuel management.
The intermittent nature of this fault points to sporadic disruptions in the sensor’s operation or its communication with the ECM, which can be tricky to diagnose and rectify.
P0464 quick overview
| Meaning | P0464: Fuel Level Sensor Circuit Intermittent |
| Is it serious? | Moderate. While not immediately threatening to the vehicle’s drivability, it can cause inconvenience and potentially lead to situations where the fuel level is misjudged. |
| Possible causes | – Faulty or corroded fuel level sensor – Issues with the wiring or connectors in the sensor circuit – Loose screws or bad connections in the instrument cluster – Potential ECM or instrument cluster faults |
| How to diagnose? | Inspect the fuel level sensor and its connectors for corrosion or damage Check the wiring and grounding points related to the fuel level circuit for issues Examine the instrument cluster for loose connections or screws Consider ECM reprogramming or replacement if the issue persists and is suggested by vehicle recalls or technical bulletins |
P0464 Meaning
When you encounter a P0464 code, think of it as trying to use a mobile phone with a signal that keeps dropping. Just like how frustrating it is when you can’t rely on your phone’s signal, not being able to trust your fuel gauge can leave you unsure about how much gas you really have, potentially leaving you stranded.
This sensor’s job is to send a steady, accurate signal to your car’s computer about your fuel level, but when the signal flickers, so does your gauge’s accuracy. Fixing this problem often involves looking at the small details, like the condition of wiring or even the tightness of screws, to ensure you stay informed about your fuel status without any nasty surprises.
Car Diagnostics Training
- Car Electrical basics
- OBD-II scanner basics
- How to use an OBD reader
- Introduction to a Bi-directional Scan tool
- OBD scanner buyer’s guide + discounts
How to fix P0464 – learn from mechanics
I looked into P0464 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.
Case #1: Nissan
Vehicle information 2001 Nissan Sentra GXE 1.8L
Issue + repair history
- Car came in with a P0464 code (Fuel Level Sensor Circuit Voltage Incorrect).
- Replaced ECM approximately 6 months ago for an unrelated no-run fault.
- Replaced the fuel level sensor with a factory sensor due to intermittent fault.
- Freeze frame showed fault with engine temperature at 187 degrees and engine speed at approximately 3000 RPM.
Other OBD2 Codes + Test Results
- OBD2 Codes: P0464.
- Scan tool voltage of level sensor circuit: Voltage shows approximately 0.8V with approximately half tank of gas.
- Checked all connectors for corrosion, none found.
- Replaced fuel level sensor and reset ECM, but code returned in 2 days.
Mechanic suggestions
- Consider replacing the instrument cluster, as similar cases have been resolved with this fix.
- Double-check the basics, including grounding at B13 and B19 near the seat belt retractors and corrosion at fuel pump and gauge cluster connectors.
- Investigate loose screws on the instrument cluster thin film circuit board connector, which could cause intermittent gauge issues.
Final fix
- Discovered loose screws on the instrument cluster upon removing it, tightened all screws, and reinstalled the cluster.
- Car was driven over the weekend with no recurrence of the P0464 code.
- Returned the car to the customer and advised them to monitor for any further problems.
Case #2: Subaru
Vehicle information 2001 Subaru Outback VDC 3.0L
Issue + repair history
- Initially diagnosed with a P0464 code (Fuel Level Sensor).
- Cleared the code, but it reset one week later.
- Replaced both fuel level sensors and the fuel temp sensor.
- Harness inspection conducted, including ground and signal checks from the ECU.
- Code continued to reset intermittently, sometimes at startup.
- H-6 engine.
Other OBD2 Codes + Test Results
- OBD2 Codes: P0464 (Fuel Level Sensor), P0183 (Fuel Temp Sensor).
Mechanic suggestions
- Consider replacing both fuel level sensors, as some Subaru wagons use two sensors, one in each part of the tank.
- Reprogram the ECM at the dealership to address potential programming issues. This reprogramming may require sending the ECM to SOA for reprogramming, which could take approximately three days.
Final fix
- Cleaned and tightened all grounds, although none appeared faulty.
- After 15 days out of the shop, the customer reported that the light had not come back on. If the light returns for the same code, reprogramming the ECM at the dealership is considered.
- Thanks to Steve from Idaho for the tip on reprogramming the ECM at the dealership.
Case #3:
Vehicle information 2001 Nissan Sentra XE 1.8L
Issue + repair history
- Vehicle diagnosed with OBD2 code P0464 (Fuel Level Sensor circuit open).
- Checked fuses, found fuel gauge on dash working fine.
- Measured voltage at PCM pin #83 (~1.89V) and confirmed good ground at PCM pin #90.
- Scanner (Geny) indicated 0.0V for the fuel level sensor voltage, contradicting direct measurement at the PCM (1.89V).
- Prior to replacement, the fuel sending unit was already replaced due to the code being set.
Other OBD2 Codes + Test Results
- OBD2 Code: P0464 (Fuel Level Sensor circuit open).
- Voltage measured: PCM @ 1.89V.
Mechanic suggestions
- Advised seeking a recall on the ECM for reflash at a Nissan dealer.
- Suggested checking ECM powers and grounds for voltage drop and replacing the ECM if necessary, as per specifications.
Final fix
- The issue was resolved by warrantying the PCM at a local Nissan dealer due to low mileage and federal emissions warranty, resolving the voltage reading discrepancy and fixing the problem.
How to diagnose P0464
I made you an overview of solving this DTC, based on all the advice that was suggested by certified mechanics to address this issue in previously mentioned service cases.
| Diagnostic Step | Brief Explanation |
|---|---|
| Inspect fuel level sensor and connectors | Look for any signs of damage or corrosion that could disrupt signal transmission. |
| Check wiring and grounding points | Ensure all connections are secure and free from corrosion, especially at grounding points near the seat belt retractors. |
| Examine the instrument cluster | Tighten any loose screws and check for bad connections that might affect the fuel gauge readings. |
| Consider ECM issues | If the problem persists, investigate if there’s a recall or if reprogramming the ECM could resolve the issue, especially in vehicles known for this fault. |
| Replace or repair as necessary | Based on findings, replace faulty components or repair connections to ensure the fuel level sensor circuit functions correctly. |
These steps, informed by real-world mechanic experiences, outline a targeted approach to solving the elusive P0464 code. It emphasizes not just the direct components involved, like the sensor itself, but also the broader system that supports its operation, including the ECM and instrument cluster.
Car Diagnostics Training
- Car Electrical basics
- OBD-II scanner basics
- How to use an OBD reader
- Introduction to a Bi-directional Scan tool
- OBD scanner buyer’s guide + discounts
I test OBD-II scanners and make DIY Engine diagnostics guides to help you solve your car problems without having to depend on the mechanic. A lot of them will try to scam you or are just no help at all. About Juraj Lukacko