GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2004 🢒 Rendezvous - AWD 🢒 Engine 🢒 Engine Controls - 3.6L (LY7) 🢒 DTC P0461

Circuit Description

The fuel level sender changes resistance based on fuel level. The engine control module (ECM) monitors the signal circuit of the fuel level sender in order to determine fuel level. When the fuel tank is full, the sender resistance is high and the ECM senses a high signal voltage. When the fuel tank is empty, the sender resistance is low and the ECM senses a low signal voltage. The ECM uses the signal circuit of the fuel level sender in order to calculate the total remaining fuel percent in the tank. The ECM sends the fuel level percent via the class 2 serial data circuit to the instrument cluster in order to control the fuel gage. The fuel level information is also used for misfire and EVAP diagnostics.

This diagnostic tests for a stuck primary fuel level sensor signal. The ECM sets this DTC if the primary fuel level sensor signal appears to be stuck based on a lack of signal variation expected during normal operation.

Conditions for Running the DTC
    • The engine is running.
    • No other fuel level sensor signal failure is present.

Conditions for Setting the DTC
    • The ECM does not detect a change in fuel level in the primary fuel tank of at least 1.0L (0.246 gal).
    • The difference between fuel consumed by the engine and a change in fuel level signal exceeds 46%.
    • The above condition is present for at least 300 seconds.

Action Taken When the DTC Sets
    • The fuel gage defaults to empty.
    • The driver information center (DIC) displays the FUEL LEVEL LOW message.
    • The ECM records the operating conditions at the time that the diagnostic test fails. The ECM displays the failure information in the Failure Records on the scan tool.

Conditions for Clearing the DTC
    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC clears after 40 malfunction free warm-up cycles.
    • The ECM receives the clear code command from the scan tool.

Diagnostic Aids
    • Use the Freeze Frame/Failure Records data in order to locate an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame/Failure Records data may help in determining the number of miles since the DTC set. The Fail Counter and Pass Counter can also help in determining the number of ignition cycles that the diagnostic test reported a pass and/or fail. Operate the vehicle within the same freeze frame conditions, including those for RPM, for engine load, for vehicle speed, for temperature, and for others. This will isolate at what point the DTC failed.
    • Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Step

Action

Yes

No

Schematic Reference: Instrument Cluster Schematics

1

Did you perform the Diagnostic System Check - Instrument Cluster ?

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2
  1. Remove the primary fuel level sender.
  2. Inspect for the following items:
    3. • The fuel level sensor is stuck, perhaps due to an interference with the fuel strainer.
    • The fuel tank contains foreign material, for instance, ice.

Did you find and correct the condition?

Go to Step 4

Go to Step 3

3

Replace the primary fuel level sensor. Refer to Fuel Level Sensor Replacement in Engine Controls - 3.6L.

Did you complete the replacement?

Go to Step 4

--

4
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK