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Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 3:  This step determines if the condition is located on the coil side or on the switch side of the fuel pump relay.
  2. 4:  This step verifies that the powertrain control module (PCM) is providing voltage to the fuel pump relay.
  3. 5:  This step tests for an open in the ground circuit to the fuel pump relay.
  4. 6:  This step determines if a voltage is constantly being applied to the fuel pump relay.
  5. 13:  This step determines if the condition with the circuit is intermittent.
Fuel Pump Electrical Circuit Diagnosis

Step Action Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference:  Engine Controls Connector End Views  or  Powertrain Control Module (PCM) Connector End Views 
1 Did you perform the Diagnostic System Check - Vehicle? Go to Step 2  Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2
  1. Turn ON the ignition, with the engine OFF.
  2. Command the fuel pump relay ON and OFF with a scan tool.
Does the fuel pump turn ON and OFF when commanded with a scan tool?		 Go to Diagnostic Aids Go to Step 3 
3  Command the fuel pump relay ON and OFF with a scan tool.
Does the fuel pump relay turn ON and OFF when commanded with a scan tool?		 Go to Step 9  Go to Step 4 
4 
  1. Turn OFF the ignition.
  2. Remove the fuel pump relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the control circuit of the fuel pump relay with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors in Wiring Systems.
  5. Command the fuel pump relay ON and OFF with a scan tool.
Does the test lamp turn ON and OFF when commanded with a scan tool?		 Go to Step 5  Go to Step 6 
5 
  1. Connect a test lamp between the control circuit of the fuel pump relay and the ground circuit of the fuel pump relay.
  2. Command the fuel pump relay ON and OFF with a scan tool.
Does the test lamp turn ON and OFF when commanded with a scan tool?		 Go to Step 19  Go to Step 22 
6  Does the test lamp remain illuminated? 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 in Wiring Systems.
Did you find and correct the condition?		 Go to Step 28  Go to Step 27 
8 Test the control circuit of the fuel pump relay for a short to ground or 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 20 
9 Turn ON the ignition, with the engine OFF.
Does the fuel pump operate continuously?		 Go to Step 10  Go to Step 11 
10
  1. Turn OFF the ignition.
  2. Remove the fuel pump relay.
  3. Turn ON the ignition, with the engine OFF.
Does the fuel pump operate continuously?		 Go to Step 21  Go to Step 26 
11 Inspect the fuel pump fuse.
Is the fuel pump fuse open?		 Go to Step 12  Go to Step 14 
12
  1. Test the supply voltage circuit of the fuel pump, between the fuel pump fuse and the fuel pump for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
  2. Replace the fuel pump fuse if necessary.
Did you find and correct the condition?		 Go to Step 28  Go to Step 13 
13 
  1. Install all removed electrical components.
  2. Install a new fuel pump fuse.
  3. Command the fuel pump relay ON with a scan tool.
  4. Inspect the fuel pump fuse.
Is the fuel pump fuse open?		 Go to Step 24  Go to Testing for Intermittent Conditions and Poor Connections
14
  1. Turn OFF the ignition.
  2. Remove the fuel pump relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the battery voltage circuit of the fuel pump relay switch with a test lamp that is connected to a good ground.
Does the test lamp illuminate?		 Go to Step 15  Go to Step 23 
15 Connect a 20-amp fused jumper wire between the battery voltage circuit of the fuel pump relay switch and the supply voltage circuit of the fuel pump.
Does the fuel pump operate?		 Go to Step 19  Go to Step 16 
16 Test the supply voltage circuit of the fuel pump, between the fuel pump relay and the fuel pump for an open or for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 28  Go to Step 17 
17
IMPORTANT: Inspect the ground circuit for being tight, corrosion on terminals, or damage to the wiring harness.
Test the ground circuit of the fuel pump for an open or for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.Did you find and correct the condition?		 Go to Step 28  Go to Step 18 
18 Test for an intermittent or for a poor connection at the fuel pump sender assembly connector. 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 
19 Test for an intermittent or for a poor connection at 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 26 
20 Test for an intermittent and for a poor connection at the harness connector of the powertrain control module (PCM). 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 
21 Repair the short to voltage in the supply voltage circuit of the fuel pump. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?		 Go to Step 28  -
22 Repair the open in the fuel pump relay ground circuit. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?		 Go to Step 28  -
23 Repair the open in the battery voltage circuit of the fuel pump relay. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?		 Go to Step 28  -
24 Test for an intermittent and for a poor connection at the fuel pump sender assembly connector within the fuel tank. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the conditions?		 Go to Step 28  Go to Step 25 
25
  1. Replace the fuel pump sender assembly. Refer to Fuel Sender Assembly Replacement .
  2. Replace the fuel pump fuse if necessary.
Did you complete the replacement?		 Go to Step 28  -
26 Replace the fuel pump relay.
Did you complete the replacement?		 Go to Step 28  -
27 Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
Did you complete the replacement?		 Go to Step 28  -
28 Operate the system in order to verify the repair.
Did you correct the condition?		 System OK Go to Step 2 
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