Diagnostic Trouble Code (DTC) P0463

Fuel Level Sensor High Voltage

 

 

Circuit Highlights

 

  • Depending upon the fuel level the fuel level sensor changes resistance.
  • The fuel level sensor contains a signal circuit and a ground circuit.
  • 5 volts on the signal circuit to the sensor is applied by the ECM.
  • All variations in this voltage arising out of changes in the resistance of the sensor are controlled by the ECM so that fuel level is known.
  • The ECM signal voltage will be high if the fuel tank is full and the sensor resistance is low.
  • The signal voltage is low because the sensor resistance is high if the tank is empty.
  • For calculating the total fuel percentage of fuel present in the fuel tank the ECM takes inputs from the fuel level sensor.
  • The ECM also uses the fuel level data for the diagnostics of evaporative emission (EVAP) and misfire.
  • The instrument panel cluster (IPC) receives all the data about the fuel level.
  • DTC sets when the ECM sees a signal voltage bigger than the operating range of the sensor.

 

 

 

When will DTC set?

 

Task boosted after DTC sets

When will DTC clear?

 

DTC  will set when

 

1)    Ignition switch remains ON.

 

 

1)  The Malfunction Indicator Lamp (MIL) will not be seen to glow.

 

 

 

 

1)  A history DTC will unset after 40 repetitive and flawless warm up cycles.

 

 

 

 

2)    Fuel level sensor signal voltage > 4.9804 V.

 

2) The ECM will store conditions from the time the diagnostic had failed.

 

2)  DTC(s) can be unset by using the scan tool.

 

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3) This data will be stored in the Freeze Frame.

 

 

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4) Failure Records will be boosted.

 

 

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Diagnostic Tools

 

  1. For locating an intermittent condition the Freeze Frame and/or Failure Records data can be used.
  2.  Data recorded in the Freeze Frame and/or Failure Records data may help to probe the number of miles since the DTC set; when DTC cannot be duplicated.
  3. The number of ignition cycles that the diagnostic reported a pass and/or fail can be probed by reading the Fail Counter and Pass Counter.
  4. Regulating the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature, etc.) will help to understand when the DTC failed.

 

 

 

 

HOW TO UNSET A DTC

DTC P0463 – Fuel Level Sensor High Voltage

 

Step

Task to be done

Positive

Negative

1

 

Carry out the EOBD system inspection.

 

Task complete?

 

Read up  

Step 2

Read up  "Diagnostic System Check"

2

  1. Switch OFF the engine.
  2. Now switch ON the ignition.
  3. Taking a scan tool look up the Fuel Level Sensor voltage parameter.

Do you see that the voltage parameter < 0.25 V?

 

Read up  

Step 4

Read up  Step 3

3

  1. Study the Freeze Frame/Failure Records for this DTC.
  2. Switch OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Regulate the vehicle within the Conditions for Running the DTC or operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did you find the DTC failing this ignition?

 

Read up  

Step 4

Read up  "Diagnostic Aids"

4

  1. De-link the fuel level sensor through the access panel under the rear seat.
  2. Now link up a 3-amp fused jumper wire between the signal circuit of the fuel level sender and the low reference circuit of the fuel level sender female terminal side.
  3. Switch OFF the engine.
  4. Now switch ON the ignition.
  5. Study the Fuel Level Sensor voltage parameter taking a scan tool.

Do you see that the voltage >0.25 V?

 

Read up  

Step 8

Read up  Step 5

5

 

Jumper the fuel level sensor signal circuit to a known good ground.

 

Do you see that the voltage > 0.25 V?

 

Read up  

Step 7

Read up  Step 6

6

1)       Probe the signal circuit of the fuel level sensor to note if there is any open, a high resistance or a short to voltage.

2)       Repair the fault if you see there is any.

 

Did you come across any flaw?

 

Read up  

Step 12

Read up  Step 8

7

1)       You need to examine the low reference circuit of the fuel level sensor for an open or a high resistance.

2)       Mend the fault if you see any.

 

Task complete?

 

Read up  

Step 12

Read up  Step 9

8

1)       See if there are any terminal shorted or any bad connections at the fuel level sensor.

2)       Repair the flaw.

 

Work over?

 

Read up

  Step 12

Read up  Step 10

9

1)       See if there are any terminal shorted or any bad connections at the engine control module (ECM).

2)       Mend the flaw.

 

Job done?

 

Read up

  Step 12

Read up  Step 11

10

1)       Look up the fuel sender assembly.

2)       Replace it with a better quality one.

 

 

Work complete?

 

Read up  

Step 12

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11

 

Get a new ECM.

 

Task finished?

 

Read up  

Step 12

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12

  1. With the help of a scan tool unset all DTCs.
  2. Switch ON the ignition for 30 seconds.
  3. Switch ON the engine now.
  4. Control the vehicle within the Conditions for running the DTC or within the conditions you noted from the Freeze Frame/Failure Records.

 Do you see that the DTC fails this ignition?

 

Read up  

Step 2

Read up  Step 13

13

 

Probe whether any additional DTCs are set.

 

Do you see any undiagnosed DTCs still being shown?

 

Read up  applicable DTC table

The system of the vehicle is good