Schematic Reference: Engine Controls Schematics

Connector End View Reference: Powertrain 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

Go to Diagnostic System Check - Engine Controls

1. Turn ON the ignition, with the engine OFF.
2. Command the fuel pump relay ON and OFF with a scan tool.
3. Repeat the commands as necessary.

Does the fuel pump turn ON and OFF?

Go to Intermittent Conditions

Go to Step 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

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?

Go to Step 5

Go to Step 6

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?

Go to Step 19

Go to Step 22

Does the test lamp remain illuminated with each command?

Go to Step 7

Go to Step 8

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 27

Go to Step 26

Test the control circuit of the fuel pump relay for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 27

Go to Step 20

Turn ON the ignition, with the engine OFF.

Does the fuel pump operate continuously?

Go to Step 10

Go to Step 11

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 25

Inspect the ECM B fuse.

Is the ECM B fuse open?

Go to Step 12

Go to Step 14

1. Test the supply voltage circuit of the fuel pump for a short to ground between the ECM B fuse and the fuel pump. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. Replace the ECM B fuse if necessary.

Did you find and correct the condition?

Go to Step 27

Go to Step 13

1. Connect all disconnected electrical components.
2. Install a new ECM B fuse.
3. Command the fuel pump relay ON with a scan tool.
4. Inspect the ECM B fuse.

Is the ECM B fuse open?

Go to Step 24

Go to Intermittent Conditions

1. Turn OFF the ignition.
2. Remove the fuel pump relay.
3. Turn ON the ignition, with the engine OFF.
4. Probe the ignition 1 voltage circuit of the fuel pump relay, switch side, with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

Go to Step 15

Go to Step 23

Connect a 20-amp fused jumper wire between the ignition 1 voltage circuit of the fuel pump relay and the supply voltage circuit of the fuel pump.

Does the fuel pump operate?

Go to Step 19

Go to Step 16

Test the supply voltage circuit of the fuel pump for an open or high resistance between the fuel pump relay and the fuel pump. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 27

Go to Step 17

Important: Inspect the ground circuit for correct tightening, corrosion on the terminals, or damage to the wiring harness.

Test the ground circuit of the fuel pump for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 27

Go to Step 18

Test for an intermittent and for a poor connection at the fuel sender cover. 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 27

Go to Step 24

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 in Wiring Systems.

Did you find and correct the condition?

Go to Step 27

Go to Step 25

Test for an intermittent and for a poor connection at the 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 27

Go to Step 26

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 27

--

Repair the open or high resistance in the ground circuit of the fuel pump relay . Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 27

--

Repair the open in the ignition 1 voltage circuit of the fuel pump relay. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 27

--

Important: Inspect for poor connections at the fuel pump, within the fuel tank, before replacing the fuel pump.

1. Replace the fuel sender. Refer to Fuel Sender Assembly Replacement .
2. Replace the ECM B fuse if necessary.

Did you complete the replacement?

Go to Step 27

--

Replace the fuel pump relay.

Did you complete the replacement?

Go to Step 27

--

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

Go to Step 27

--

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2