Circuit Description
The powertrain control module (PCM) uses the fuel level input in order to calculate the expected vapor pressures within the fuel system. These vapor pressures vary as the fuel level changes. The vapor pressure is critical in determining if the Evaporative Emissions System is operating properly. The PCM also uses the fuel level in order to determine if the fuel level is too high or too low to be able to accurately detect EVAP system malfunction.
Conditions For Running the DTC
The ignition is ON.
The system voltage is between 11.0 and 16.0 volts.
Conditions For Setting the DTC
The fuel level has not changed more than 1.6 percent (4 counts) in 120 miles.
Action Taken When the DTC Sets
| • | The PCM records the operating conditions at the time the diagnostic fails. The Failure Records buffers will store this information. |
| • | A history DTC is stored. |
| • | The fuel tank level defaults to 40 percent. |
Conditions for Clearing the DTC
| • | A history DTC clears after 40 consecutive warm up cycles without a fault. |
| • | Use a scan tool to clear the DTCs. |
Diagnostic Aids
An intermittent may be caused by any of the following conditions:
| • | A poor connection |
| • | Rubbed through wire insulation |
| • | A broken wire inside the insulation |
Thoroughly test any circuitry that is suspected of causing the intermittent complaint. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Wiring Systems.
Verify adequate fuel is in the tank. By using the scan tool you are using the same sender the gauge on the dash is using. The sender may be stuck.
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
The fuel level display on the scan tool is displayed in percentage of fuel in the fuel tank. It is also important to know approximately how much fuel is in the tank prior to performing this step.
-
The replacement PCM must be programmed and the Crankshaft Position System Variation Learn Procedure must be performed.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||
Important:
Does the fuel level value read either specified value? | 0 %, 100 % | Go to Diagnostic Aids | ||||||
3 |
Does the fuel level value read at the specified level? | 100 % | ||||||
4 |
Does the fuel level value read at the specified level? | 0 % | ||||||
5 |
Did you find and correct the condition? | -- | ||||||
6 |
Does the test lamp illuminate? | -- | ||||||
7 |
Did you find and correct the condition? | -- | ||||||
8 |
Did you find and correct the condition? | -- | ||||||
|
Important:: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | -- | -- | ||||||
10 |
Did you find and correct the condition? | -- | ||||||
11 | Replace the fuel level sensor. Refer to Fuel Level Sensor Replacement . Did you complete the replacement? | -- | -- | |||||
12 |
Does the DTC reset? | -- | System OK |
