Circuit Description
The engine control module (ECM) uses the signal from the fuel level sensor to calculate expected vapor pressure within the fuel system. Vapor pressure varies as the fuel level changes. The fuel level signal also used to determine if the fuel level is too high or too low to be able to detect evaporative emission (EVAP) system faults. This DTC detects a continuous short to low or open in either the signal circuit or the fuel level sensor.
Conditions for Setting the DTC
| • | The fuel level sensor output is greater than 98 percent of the sensor reading scale. |
| • | The ignition is ON. |
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffers. |
| • | A history DTC is stored. |
Conditions for Clearing the MIL/DTC
| • | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
| • | DTCs can be cleared by using the scan tool. |
| • | Disconnect the ECM battery feed for more than 10 seconds. |
Diagnostic Aids
Inspect the harness connector for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and a poor terminal-to-wire connection.
Inspect the wiring harness for damage.
A stuck fuel level sensor may cause the DTC to set.
If the DTC P0462 cannot be duplicated, the information included on the Failure Records data can be useful in determining the vehicle conditions when the DTC was first set.
Resistance checks for the fuel level sensor:
| • | Empty equals 280 ohms or over. |
| • | Half full equals about 90 ohms. |
| • | Full equals 38 ohms or less. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
The Diagnostic System Check - Engine Controls prompts the technician to complete some basic checks and store the Freeze Frame and Failure Records data on the scan tool, if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored on the scan tool for later reference.
-
Determine if a fault is present. Review the Freeze Frame data to determine when the DTC set. Always record this information.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Perform the Diagnostic System Check - Engine Controls. Was the check performed? | -- | Go to Step 2 | ||
Is DTC P0463 set? | -- | Go to Step 3 | Go to Diagnostic Aids | |
3 |
Is the voltage within the specified value? | 0.4-4.5 V | Go to Step 4 | Go to Step 6 |
4 | Inspect for a proper ground connection at the fuel tank and repair as needed. Is the repair complete? | -- | Go to Step 11 | Go to Step 5 |
5 |
Does the fuel level sensor value on the scan tool increase and then decrease steadily when the float is moved? | -- | Go to Diagnostic Aids | Go to Step 8 |
6 | Inspect for a short to voltage in the fuel level sensor circuit and repair as needed. Is the repair necessary? | -- | Go to Step 7 | Go to Step 9 |
7 | Repair the short to voltage in the fuel level sensor circuit between the fuel level sensor harness connector and the fuel level sensor. Is the repair complete? | -- | Go to Step 11 | -- |
8 |
Is the repair complete? | -- | Go to Step 11 | -- |
9 |
Is the voltage within the specified value? | 4-5 V | Go to Step 10 | Go to Diagnostic Starting Point - Instrument Panel, Gages and Console in Instrument Panel, Gages, and Console |
10 |
Is the repair complete? | -- | Go to Step 11 | -- |
11 |
Does the scan tool indicate that this diagnostic ran and passed? | -- | Go to Step 12 | Go to Step 2 |
12 | Are any DTCs displayed that have not been diagnosed? | -- | System OK |
