Circuit Description
The fuel level sender changes resistance based on the fuel level. The powertrain
control module (PCM) 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 PCM senses a high signal voltage. When the fuel tank is empty, the sender
resistance is low and the PCM senses a low signal voltage. The PCM uses the signal
circuit of the fuel level sender in order to calculate the total remaining fuel percent
in the tank. The PCM sends the fuel level message via the controller area network
(CAN) serial data circuit to the body control module (BCM). The BCM sends the fuel
level percent to the instrument panel cluster (IPC) via the class 2 data circuit
to display on the fuel gage. The fuel level information is also used for misfire and
evaporative emission (EVAP) diagnostics.
This diagnostic tests for an intermittent fuel level sender signal. If a change
in fuel level is detected DTC P0442 is aborted due to a refueling event. A
refueling event test is executed to confirm that a refueling event has occurred. If
refueling is confirmed, the test is considered passing. Otherwise, the DTC will set
indicating an intermittent signal problem.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0464 Fuel Level Sensor Circuit Intermittent
Conditions for Running the DTC
Conditions for Setting the DTC
| • | The fuel level change is greater than 10 percent. |
| • | The above condition is present for more than 30 seconds. |
Action Taken When the DTC Sets
| • | The PCM records the operating conditions at the time the diagnostic fails.
The PCM 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 PCM 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. |
| • | If the DTC sets without a refueling event follow the Fuel Gage Inaccurate
or Inoperative Diagnosis. |
