P0461
DTC P0461CIRCUIT DESCRIPTION
The fuel level sender changes resistance based on the fuel level. The 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 BCM. The BCM sends that class 2 message to the IPC in order to display the fuel level percent on the fuel gage. The fuel level information is also used for misfire and EVAP diagnostics.
This diagnostic tests for a stuck fuel level sender signal. The ECM sets this DTC if the fuel level sender signal appears to be stuck based on a lack of signal variation expected during normal operation.
CONDITIONS FOR RUNNING THE DTC
The ignition is ON.
CONDITIONS FOR SETTING THE DTC
The ECM does not detect a change in fuel level of at least 1.6 percent over a distance of 193 km (120 mi).
ACTION TAKEN WHEN THE DTC SETS
- The fuel gage defaults to empty.
- The ECM records the operating conditions at the time the diagnostic fails. The ECM stores 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 and/or Failure Records data in order to locate an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data may aid in determining the number of miles since the DTC set. The Fail Counter and Pass Counter can also aid in determining the number of ignition cycles that the diagnostic reported a pass and/or fail. Operate the vehicle within the same freeze frame conditions, i.e. RPM, engine load, vehicle speed, temperature, etc. This will isolate when the DTC failed.
TEST
