Diagnostic Test

1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. For future reference, run and save a vehicle Scan Report and all related recorded data.
3. With the scan tool, erase all DTCs.
4. Turn the ignition off for a minimum of 75.0 seconds.
5. Turn the ignition on.
6. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read DTCs.

   Did the DTC return?

   Yes 

   • Go To  2

   No 

   • Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT DTC .

1. Refer to the recorded DTCs.

   Are there any Run/Start Relay Control circuit DTCs present in any other modules?

   Yes 

   • Perform the applicable diagnostic procedure(s).

   No 

   • Go To  3

1. Check the PDC layout in the wiring information to determine if the Fuel Pump Relay is removable or a Printed Circuit Board (PCB) Relay in the PDC.

   What type of relay is the vehicle configured with?

   Removable Relay 

   • Go To  4

   PCB Relay 

   • Go To  5

1. Turn the ignition off.
2. Remove the Fuel Pump Relay from the relay connector in the PDC.
3. Turn the ignition on.
4. Using a 12-volt test light connected to ground, probe the Battery supply voltage from the Run/Start Relay Output at terminal 85 at the Fuel Pump Relay connector in the PDC.

   Is the test light illuminated and bright?

   Yes 

   • Go To  6

   No 

   • Check all of the fuses in the PDC. If a fuse is open, replace the fuse and retest. If no problems are found with the fuses, check the Battery supply to the PDC and the operation of the Run/Start Relay. If no problems are found replace the PDC in accordance with the Service Information.
   • Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .

1. Using a DMM, back probe and measure the voltage on the Fuel Pump (K31) Control circuit at the PDC connector.
   NOTE:

   The relay must be commanded off when checking for voltage on the circuit. With the relay Low Side Driver control circuit commanded off the voltage should be approximately equal to Battery voltage on the (K31) Fuel Pump Control circuit.

   Is the voltage approximately equal to Battery voltage?

   Yes 

   • Go To  6

   No 

   • Check all of the fuses in the PDC. If a fuse is open, replace the fuse and retest. If no problems are found with the fuses, check the Battery supply to the PDC and the operation of the Run/Start Relay. If no problems are found replace the PDC in accordance with the Service Information.
   • Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .

1. If the relay is removable, reinstall the Fuel Pump Relay in the PDC.
2. Turn the ignition on.
3. Using a 12-volt test light connected to ground, back probe the Fuel Pump (K31) Control circuit at the PDC connector.
   NOTE:

   The relay should make an audible click when closing. Another way to verify that the relay closed is to back probe and check for voltage on the relay output circuit.

   Did the relay close when connecting the Fuel Pump (K31) Control circuit to ground through the test light?

   Yes 

   • Go To  7

   No 

   • If this is a PCB relay, replace the Power Distribution Center (PDC) in accordance with the Service Information.
   • If this is a removable relay and the PDC has an internal PCB and harness connectors, isolate and check the continuity between terminal 86 of the relay connector and the output terminal at the PDC connector. If the resistance is below 3.0 Ohms, replace the Fuel Pump Relay. If the resistance is above 3.0 Ohms, replace the Power Distribution Center (PDC) in accordance with the Service Information.
   • If this is a removable relay and the wiring harness is directly hard wired into the PDC, replace the Vacuum Pump Relay.
   • Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .

1. The ignition must be off when checking the continuity of a circuit.
2. Isolate the circuit by disconnecting the PCM and the component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
3. Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note:  The meter leads can add resistance to the measurement value.
4. Connect one lead of the DVOM to the circuit being tested at the component harness connector.
5. Connect the other lead of the DVOM to the circuit being tested at the PCM harness connector.

Is the resistance below 3.0 Ohms?

Yes 

• Go To  8

No 

• Repair the circuit for an open or high resistance.
• Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .

1. Turn the engine off.
2. Reconnect the PDC harness connector.
3. Reconnect the PCM harness connector.
4. Disconnect the Fuel Pump harness connector.
5. Turn the ignition on, engine off.
6. Measure the voltage across the Fuel Pump (N1) Control Output circuit and the (Z916) Fuel Pump Ground circuit at the Fuel Pump harness connector.

   Does the voltage read between 10.7-16.0 volts?

   Yes 

   • Go To  10

   No 

   • Go To  9

1. Turn the ignition off.
2. Measure the resistance between ground and the (Z916) Fuel Pump Ground circuit at the Fuel Pump harness connector.

   Is the resistance above 3.0 Ohms?

   Yes 

   • Repair the (Z916) Fuel Pump Ground circuit for an open/high resistance.
   • Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .

   No 

   • Go To  10

1. The ignition must be off when checking a circuit for continuity to ground.
2. Isolate the circuit by disconnecting the PDC and every component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
3. Connect the negative lead of the DVOM to a known good ground.
4. With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.

Is there continuity between ground and the circuit being tested?

Yes 

• Repair the circuit for a short to ground. Use the wiring diagram as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
• Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .

No 

• Go To  11

1. The ignition must be off when checking the continuity of a circuit.
2. Isolate the circuit by disconnecting the PDC and the component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
3. Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DMM. Note:  The meter leads can add resistance to the measurement value.
4. Connect one lead of the DMM to the circuit being tested at the component harness connector.
5. Connect the other lead of the DMM to the circuit being tested at the PDC harness connector.

Is the resistance below 3.0 Ohms?

Yes 

• Go To  12

No 

• Repair the circuit for an open or high resistance.
• Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .

1. Replace the Fuel Pump in accordance with the Service Information.
2. Connect the Fuel Pump and PCM harness connectors.
3. Turn the ignition on.
4. With the scan tool, erase PCM DTCs.
5. Start the engine and run it until it reaches operating temperature.
6. With the scan tool, read DTCs.

   Did the DTC return?

   Yes 

   • Go To  13

   No 

   • Replacing the Fuel Pump repaired the condition.
   • Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .

1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
   • Proper connector installation.
   • Damaged connector locks.
   • Corrosion.
   • Other signs of water intrusion.
   • Weather seal damage (if equipped).
   • Bent terminals.
   • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
   • Terminals that have been pushed back into the connector cavity.
   • Check for spread terminals and verify proper terminal tension.

   Repair any conditions that are found.

5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. With the scan tool, read DTCs.

    Did the DTC return?

    Yes 

    • Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
    • Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .

    No 

    • Repairing the poor connections repaired the condition.
    • Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .