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 transfer 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. If the ECM commands the transfer fuel pump ON and a predetermined change in the front and rear fuel level sensors does not occur, this DTC sets.
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 (0.8-2.6 gallons). |
| • | The above conditions are met for 20 seconds before the fuel transfer pump is commanded ON. |
| • | The fuel transfer pump is commanded ON for 120 seconds. |
Conditions for Setting the DTC
The ECM detects a primary fuel level increase and a secondary fuel level decrease of less than 2.6 liters (0.70 gallons) each, within 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. |
Conditions for Clearing the DTC
| • | A current DTC Last Test Failed clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic. |
| • | Clear the DTC with a scan tool. |
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.
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This step verifies the fuel transfer pump operation. If the test lamp flashes, then the fuel transfer pump and circuits are OK.
-
This step tests for a fuel flow condition.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||
2 | Is DTC P0461, P0462, P0463, P2066, P2067, or P2068 also set? | -- | Go to Diagnostic Trouble Code (DTC) List in Instrument Panel, Gages, and Console | Go to Step 3 | ||||
|
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? | -- | Go to Step 9 | Go to Step 4 | |||||
4 |
Does the test lamp illuminate? | -- | Go to Step 5 | Go to Step 22 | ||||
5 |
Does the test lamp turn ON and OFF? | -- | Go to Step 19 | Go to Step 6 | ||||
6 | Does the test lamp remain illuminated? | -- | Go to Step 7 | Go to Step 8 | ||||
7 | Test the fuel pump relay control circuit for a short to voltage. 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 fuel pump relay control circuit 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 | ||||
9 | Command the fuel transfer pump ON with a scan tool. Does the fuel transfer pump operate? | -- | Go to Step 14 | Go to Step 10 | ||||
10 |
Does the test lamp illuminate? | -- | Go to Step 11 | Go to Step 24 | ||||
Probe the fuel transfer pump supply voltage circuit with a test lamp that is connected to battery voltage. Does the test lamp flash? | -- | Go to Step 19 | Go to Step 12 | |||||
12 | Test the fuel transfer pump supply voltage 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 transfer pump with a test lamp that is connected to battery voltage. Does the test lamp illuminate? | -- | Go to Step 20 | Go to Step 23 | ||||
14 | Observe the fuel level sensor rear tank parameter with a scan tool. Is the voltage more than 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 | ||||
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 25 | ||||
20 | Inspect for poor connections at the harness connector of the fuel transfer 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 26 | ||||
21 | Inspect for poor connections at the harness connector of the 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 27 | ||||
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 transfer 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 transfer 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 | |||||
