The control module enables the fuel pump relay when the ignition switch is turned ON. The control module will disable the fuel pump relay within two seconds unless the control module detects ignition reference pulses. The control module continues to enable the fuel pump relay as long as ignition reference pulses are detected. The control module disables the fuel pump relay within 2 seconds if ignition reference pulses cease to be detected and the ignition remains ON.
Step | Action | Yes | No | ||||
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Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Engine Control Module Connector End Views | |||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |||||
2 |
Does the fuel pump turn ON and OFF? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 | ||||
3 | Command the fuel pump relay ON and OFF with a scan tool. Do you hear the fuel pump relay click when you command the fuel pump relay ON and OFF? | Go to Step 9 | Go to Step 4 | ||||
4 |
Does the test lamp turn ON and OFF? | Go to Step 5 | Go to Step 6 | ||||
5 |
Does the test lamp turn ON and OFF? | Go to Step 21 | Go to Step 24 | ||||
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 voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 29 | Go to Step 28 | ||||
8 | Test the control circuit of the fuel pump relay for a short to ground, an open, or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 29 | Go to Step 22 | ||||
9 | Turn ON the ignition, with the engine OFF. Does the fuel pump operate continuously? | Go to Step 10 | Go to Step 11 | ||||
10 |
Does the fuel pump operate continuously? | Go to Step 23 | Go to Step 27 | ||||
11 | Inspect the fuel pump fuse. Is the fuel pump fuse open? | Go to Step 12 | Go to Step 15 | ||||
12 |
Did you find and correct the condition? | Go to Step 29 | Go to Step 13 | ||||
13 |
Did you find and correct the condition? | Go to Step 29 | Go to Step 14 | ||||
14 |
Is the fuel pump fuse open? | Go to Step 26 | Go to Testing for Intermittent Conditions and Poor Connections | ||||
15 |
Does the test lamp illuminate? | Go to Step 16 | Go to Step 25 | ||||
16 | Connect a 10-amp fused jumper wire between the battery voltage circuit of the fuel pump relay and the supply voltage circuit of the fuel pump. Does the fuel pump operate? | Go to Step 21 | Go to Step 17 | ||||
17 |
Did you find and correct the condition? | Go to Step 29 | Go to Step 18 | ||||
18 |
Important: Inspect the ground circuit for proper torque, corrosion on the terminals, or damage to the wiring harness. Test the ground circuit of the fuel pump for an open or high resistance between the inline harness connector and ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 29 | Go to Step 19 | ||||
19 | Test for an intermittent and for a poor connection at the inline harness connector of the fuel tank modules. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 29 | Go to Step 20 | ||||
20 |
Did you find and correct the condition? | Go to Step 29 | Go to Step 26 | ||||
21 | Test for an intermittent and for a poor connection at the fuel pump relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 29 | Go to Step 27 | ||||
22 | Test for an intermittent and for a poor connection at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 29 | Go to Step 28 | ||||
23 | Repair the short to voltage in the supply voltage circuit of the fuel pump. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 29 | -- | ||||
24 | Repair the open or high resistance in the ground circuit of the fuel pump relay. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 29 | -- | ||||
25 | Repair the open in the battery voltage circuit of the fuel pump relay. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 29 | -- | ||||
26 |
Important: Inspect for poor connections at the fuel pump, within the fuel tank, before replacing the fuel pump.
Did you complete the replacement? | Go to Step 29 | -- | ||||
27 | Replace the fuel pump relay. Did you complete the replacement? | Go to Step 29 | -- | ||||
28 | Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 29 | -- | ||||
29 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |