P0464
DTC P0464 FUEL LEVEL SENSOR "A" CIRCUIT INTERMITTENTComponent Location:
GENERAL DESCRIPTION
In order to measure the Fuel Level within the tank, the Fuel Level Sender consists of a variable resistor card mounted in the Fuel Pump and Sender unit (located in the fuel tank). A float located in the fuel tank swivels up and down as fuel level varies. A wiper is attached to the float and sweeps across the resistor card, thus providing a variable resistive input to the PCM. As the float sweeps across the Fuel Level Sender resistor card, the input voltage to the PCM varies accordingly. The PCM has calibrations and software which convert this analog voltage to a Fuel Level reading.
DTC DESCRIPTION
The Fuel Level Noisy Signal Diagnostic monitors variations in Fuel Level and looks for erratic or irregular behavior. When the Fuel Level is determined to display unstable, the Fuel Level Sender is determined to be failed.
When the Fuel Level Sender fails, it may cause the Evaporative System Diagnostic to function improperly since it relies on Fuel Level in its leak detection algorithm. A failed Fuel Level Sender will also provide misleading Fuel Level information to the driver (in cases where the PCM drives the fuel gauge).
Checking output signals from FLS under detecting condition, if Difference between previous and current Fuel Level Signal is high than 0.8 V, PCM sets P0464. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
DTC Detecting Condition:
Specification:
Schematic Diagram:
MONITOR SCANTOOL DATA
1. Ignition "OFF".
2. Connect Scantool and Engine "ON".
3. Monitor "FLS" parameter on Current Data.
4. Is the "FLS" parameter displayed correctly?
YES: Fault is intermittent caused by poor contact in Sensor's and/or PCM's connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection,bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
NO: Go to "Terminal and Connector Inspection" procedure.
TERMINAL AND CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES: Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO: Go to "Signal Circuit Inspection "procedure.
SIGNAL CIRCUIT INSPECTION
1. IG "OFF" and disconnect FLS connector.
2. IG "ON" & ENG "OFF"
3. Measure voltage between terminal 1 of FLS harness connector and chassis ground.
Specification : Approx.11.46 V
4. Is the measured voltage within specification?
YES: Go to "Ground Circuit Inspection" procedure.
NO: Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
GROUND CIRCUIT INSPECTION
1. IG "OFF"
2. Disconnect FLS & PCM connector.
3. Measure resistance between terminal 3 of FLS harness connector and chassis ground
Specification : Approx. below 1 Ohm
4. Is the measured resistance within specification ?
YES: Go to "Component Circuit Inspection" procedure.
NO: Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
COMPONENT INSPECTION
1. Ignition "OFF"
2. Disconnect Fuel Level Sensor connector and Remove Fuel Sender from fuel tank.
3. Measure resistance between terminal 1 and 3 of Fuel Sender.(Component Side)
4. Does the resistance of FLS change as lifting up and down the fuel level float?
YES: Substitute with a known - good PCM and check for proper operation. If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.
NO: Substitute with a known - good Fuel Level Sensor and check for proper operation. If the problem is corrected, replace Fuel Level Sensor and go to "Verification of Vehicle Repair" procedure.
NOTE: There is a memory reset function on Scantool that can erase optional parts automatically detected and memorized by PCM. Before or after testing PCM on the vehicle, use this function to reuse the PCM on the others
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions
4. Monitor that all readiness tests have been verified as" Complete"
5. Are any DTCs present?
YES: Go to the applicable trouble shooting procedure.
NO: System is performing to specification at this time.