Fuel Level Sensor - DTC P0462/Revised Diagnostics
File In Section: 06 - Engine/Propulsion SystemBulletin No.: 01-06-04-025
Date: April, 2001
SERVICE MANUAL UPDATE
Subject:
Revised DTC P0462 Fuel Level Sensor Circuit Low Voltage Diagnostic Procedure
Models:
2000 Chevrolet Camaro
2000 Pontiac Firebird With 3.8L Engine
This bulletin is being issued to revise the DTC P0462 Fuel Level Sensor Circuit Low Voltage diagnostic procedure in the Engine Controls - 3.8L sub-section of the Service Manual. Please replace the current information in the Service Manual with the following information.
The following information has been updated within SI2000. If you are using a paper version of this Service Manual, please make a reference to this bulletin on the affected page.
Circuit Description
The fuel level sensor changes resistance based on fuel level. The fuel level sensor has a signal circuit and a ground circuit. The PCM applies a voltage (about 5.0 volts) on the signal circuit to the sensor. The PCM monitors changes in this voltage caused by changes in the resistance of the sensor to determine fuel level.
When the fuel tank is full, the sensor resistance is high, and the PCMs signal voltage is only pulled down a small amount through the sensor to ground. Therefore, the PCM will sense a high signal voltage (fuel tank full). When the fuel tank is empty, the sensor resistance is low, and the signal voltage is pulled down a greater amount. This causes the PCM. to sense a low signal voltage (fuel tank empty). The PCM uses inputs from the fuel level sensor to calculate the total fuel remaining in the fuel tank. This information is then sent to the fuel gauge.
This DTC sets when the PCM senses a signal voltage lower than the normal operating range of the sensor.
Conditions for Running the DTC
The ignition switch is in the RUN position.
Conditions for Setting the DTC
^ The fuel level sensor voltage is below 0.39 volts.
^ All conditions present for 6.0 minutes.
Diagnostic Aids
The vehicle fuel gauge displays empty with this DTC set.
Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed.
Test Description
The numbers refer to the step numbers on the diagnostic table as shown.
2. This step determines if the fault is present.
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