Circuit Description
The Powertrain Control Module (PCM) uses a fuel level input in order to calculate the expected vapor pressures within the fuel system. These vapor pressure vary as the fuel level changes. The vapor pressure is critical in determining if the evaporative emission (EVAP) 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 an EVAP system malfunction.
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The system voltage is between 11-16 volts. |
Conditions for Setting the DTC
The fuel level sensor reading is more than 98 percent for 25 seconds or more.
Action Taken When the DTC Sets
| • | The PCM will record the operating conditions under which the diagnostic fails. This information is stored in the Failure Records buffer. |
| • | A history DTC is stored. |
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 condition may be caused by one of the following: |
| - | Improper resistance on the resistor card, normal resistance is 40-240 OHM |
| - | Contamination on the resistor card |
| - | Intermittent open on the resistor card |
| • | Inspect for the following conditions that may cause intermittents: |
| - | Poor electrical connections |
| - | Rubbed through wire insulation |
| - | A wire that is broken inside the wire insulation |
| • | Thoroughly inspect any circuitry that is suspected as causing the intermittent complaint. Inspect for the following conditions: |
| - | Backed out terminals |
| - | Improper mating |
| - | Broken locks |
| - | Improperly formed or damaged terminals |
| - | Poor terminal to wire connections |
| • | Before replacing the PCM, inspect the PCM electrical connector terminals for the following conditions: |
| - | Improper mating |
| - | Broken locks |
| - | Physical damage to the wiring harness |
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
This step determines if the malfunction is present.
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Using the 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 help to determine how many miles since the DTC set. The Fail Counter and Pass Counter can also help to determine how many ignition cycles the diagnostic reported a pass and/or fail. Operate the vehicle within the same freeze frame conditions such as RPM, load, vehicle speed, temperature, or other conditions that you observed. This will isolate when the DTC failed.
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Use the connector test adapter kit in order to avoid damage to the harness connector terminals.
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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? | -- | ||
Is the fuel level sensor parameter reading above the specified value? | 98% | |||
Does the DTC reset? | -- | Go to Diagnostic Aids | ||
Does the fuel level sensor signal circuit voltage read near the specified value? | 5.0 V | |||
5 |
Did you find and correct the condition? | -- | ||
6 | With a test lamp connected to B+, probe the fuel level sensor ground circuit. Does the test lamp illuminate? | -- | ||
7 |
Did you find and correct the condition? | -- | ||
8 |
Did you find and correct the condition? | -- | ||
9 |
Does the DMM display continuity within the specified range from the fuel level sensor signal circuit to any other PCM circuit? | 0-2ohms | ||
10 |
Did you find and repair the condition? | -- | ||
11 | Repair the fuel level sensor ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | ||
12 | Repair the short between the fuel level sensor signal circuit and the PCM circuit that had continuity. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
13 | Replace the fuel level sensor. Refer to Fuel Level Sensor Replacement . Did you complete the replacement? | -- | -- | |
|
Important: Refer to Powertrain Control Module Replacement/Programming . If the circuit is OK, replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | -- | ||
15 |
Does the DTC reset? | -- | System OK |
