Circuit Description
The fuel pump is located on the left frame rail between the fuel tanks. The engine control module (ECM) provides ignition positive voltage to the coil side of the fuel pump relay. The ECM energizes the fuel pump relay, which applies power to the fuel pump. Fuel is transferred from the rear fuel tank to the front fuel tank in order to ensure all of the usable fuel volume is available to the engine. This DTC sets when the ECM commands the transfer fuel pump ON and a predetermined change in the front and rear fuel level sensors does not occur.
Conditions for Running the DTC
| • | DTC P0500 is not set. |
| • | The engine is running. |
| • | The vehicle speed is 0 km/h (0 mph). |
| • | The primary fuel level is less than 25 liters (6.6 gallons). |
| • | The secondary fuel level is between 3-10 liters (0.7-2.6 gallons). |
| • | The above conditions are met for 20 seconds before the pump is commanded ON. |
| • | The fuel pump is commanded ON for 120 seconds. |
Conditions for Setting the DTC
The ECM does not detect a change of 2.6 liters (0.70 gallons) in the primary and secondary fuel level sensors with the fuel pump commanded ON for 120 seconds.
Action Taken When the DTC Sets
| • | The control module stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records. |
| • | The driver information center, if equipped, may display a message. |
| • | The fuel gage will be commanded to empty. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step determines if the condition is on the coil side, or the switch side of the fuel pump relay. Listen for an audible click as the fuel pump relay is commanded ON and OFF. Repeat the commands as necessary in order to verify the fuel pump relay operation.
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This step tests the control circuit of the fuel pump relay. The test lamp should turn ON and OFF with the scan tool commands. Repeat the commands as necessary.
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This step verifies the fuel pump operation. Listen for the fuel pump as you command the fuel pump ON. Repeat the commands as necessary in order to verify the fuel pump operation.
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This step tests the ignition voltage circuit of the fuel pump relay.
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This step verifies the fuel pump operation. If the test lamp blinks, then the fuel pump and circuits are OK.
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The rear fuel level sensor voltage must be above the specified value in order to continue with the diagnostic procedure.
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This step tests for a fuel flow condition. If the rear fuel level sensor voltage does not decrease as the fuel pump is operating, a restriction in the fuel lines or rear sender is the probable cause of the DTC.
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If a restriction in the fuel lines, or rear fuel sender is not isolated, a mechanical condition exists in the fuel pump. Replace the fuel pump.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views | ||||||||
1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | |||||
2 | Is DTC P0461, P0462, P0463, P1431, P1432, or P1433 also set? | -- | Go to Diagnostic Trouble Code (DTC) List in Instrument Panel, Gages, and Console | Go to Step 3 | ||||
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Important: The fuel level must be between 25-50 percent in order to perform this diagnostic procedure. If the fuel level is not within this range, misdiagnosis will occur.
Does the fuel pump relay click as you command the fuel pump ON and OFF? | -- | Go to Step 9 | Go to Step 4 | |||||
4 |
Is the test lamp illuminated? | -- | Go to Step 5 | Go to Step 22 | ||||
Does the test lamp turn ON and OFF? | -- | Go to Step 19 | Go to Step 6 | |||||
6 | Does the test lamp remain illuminated with each command? | -- | Go to Step 7 | Go to Step 8 | ||||
7 | Test the control circuit of the fuel pump relay for a short to B+. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 28 | Go to Step 26 | ||||
8 | Test the control circuit of the fuel pump relay for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 28 | Go to Step 21 | ||||
Command the fuel pump ON with a scan tool. Does the fuel pump run? | -- | Go to Step 14 | Go to Step 10 | |||||
Is the test lamp illuminated? | -- | Go to Step 11 | Go to Step 24 | |||||
Probe the fuel pump supply circuit with a test lamp connected to B+. Does the test lamp blink? | -- | Go to Step 19 | Go to Step 12 | |||||
12 | Test the fuel pump supply circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 28 | Go to Step 13 | ||||
13 | Probe the ground circuit of the fuel pump with a test lamp connected to B+. Is the test lamp illuminated? | -- | Go to Step 20 | Go to Step 23 | ||||
Monitor the rear fuel level sensor voltage with a scan tool. Is the rear fuel level sensor voltage above the specified value? | 1 V | Go to Step 16 | Go to Step 15 | |||||
15 | Add the specified amount of fuel to the fuel tank. Did you complete the action? | 19 L (5 Gal) | Go to Step 16 | -- | ||||
Does the rear fuel level sensor voltage decrease as the fuel pump is operating? | -- | Go to Step 17 | Go to Step 18 | |||||
17 |
Does the fuel volume measure more than the specified value? | 2.6 L (0.70 gal) | Go to Intermittent Conditions | Go to Step 18 | ||||
Inspect for the following conditions:
Did you find and correct the condition? | -- | Go to Step 28 | Go to Step 26 | |||||
19 | Inspect for poor connections at the harness connector of the fuel pump relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 28 | Go to Step 24 | ||||
20 | Inspect for poor connections at the harness connector of the fuel pump. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 28 | Go to Step 25 | ||||
21 | Inspect for poor connections at the harness connector of the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 28 | Go to Step 26 | ||||
22 | Repair the open ground circuit of the fuel pump relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 28 | -- | ||||
23 | Repair the open ground circuit of the fuel pump. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 28 | -- | ||||
24 | Repair the open ignition 1 voltage circuit of the fuel pump relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 28 | -- | ||||
25 | Replace the fuel pump relay. Did you complete the replacement? | -- | Go to Step 28 | -- | ||||
26 | Replace the fuel pump. Refer to Fuel Pump Replacement . Did you complete the replacement? | -- | Go to Step 28 | -- | ||||
27 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 28 | -- | ||||
28 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 29 | ||||
29 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |||||
