Wrangler 2WD V6-3.8L (2008)
Reconnect the Back Flow Return Line at the Fuel Pressure Solenoid.
Disconnect the Back Flow Return Line at the High Pressure Fuel Pump.
Apply air pressure to the High Pressure Pump end of the Back Flow Return Line.
Is air movement evident at the Fuel Pump Module end of the Back Flow Return Line?
Yes
-
Test Complete
No
-
Repair the Back Flow Return Line for kinks or broken line.
-
Perform the PCM Verification Test. See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code Tests and Associated
Procedures/Verification Tests/Powertrain Verification Test
8. (Z905) FUEL PUMP GROUND CIRCUIT OPEN OR HIGH RESISTANCE
Turn the ignition off.
Disconnect the Fuel Pump Module harness connector.
Using a 12 volt test light connected to 12 volts, check the (Z905) Fuel Pump Motor Ground circuit at the Fuel Pump Module harness connector.
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated and bright?
Yes
-
Go to 9
No
-
Repair the (Z905) Fuel Pump Ground circuit for an open circuit or high resistance.
-
Perform the PCM Verification Test. See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code Tests and Associated
Procedures/Verification Tests/Powertrain Verification Test
9. (N1) FUEL PUMP CONTROL OUTPUT CIRCUIT CHECK
Using a 12 volt test light connected to 12 volts, check the (N1) Fuel Pump Motor Ground circuit at the Fuel Pump Module harness connector.
Turn the ignition on.
With a scan tool, actuate the fuel pump control to ON (100%).
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated and bright?
Yes
-
Replace the Fuel Pump Module.
-
Perform the PCM Verification Test. See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code Tests and Associated
Procedures/Verification Tests/Powertrain Verification Test
No
-
Repair the (N1) Fuel Pump Control Output circuit for an open, short to ground or short to voltage. If the Fuel Pump Control Output circuit is o.k.,
replace the Totally Integrated Power Module.
-
Perform the PCM Verification Test. See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code Tests and Associated
Procedures/Verification Tests/Powertrain Verification Test