Grand Cherokee 4WD V8-4.7L Flex Fuel (2009)
4. Install the Fuel Pressure Decay Tester 8978 between the fuel supply line and the fuel pump module.
5. Ignition on, engine not running.
6. Using the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge.
NOTE: Fuel pressure specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
CAUTION: Stop All Actuations.
Is the fuel pressure within specification now?
Yes
-
Repair/replace fuel supply line as necessary.
-
Perform the POWERTRAIN VERIFICATION TEST. See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code
Tests and Associated Procedures/Verification Tests/Powertrain Verification Test.
No
-
Go To 4
4. CHECKING FUEL INLET STRAINER
WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or
line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
1. Turn the ignition off.
2. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer.
Is the Fuel Inlet Strainer plugged?
Yes
-
Replace the Fuel Pump Inlet Strainer.
-
Perform the POWERTRAIN VERIFICATION TEST. See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code
Tests and Associated Procedures/Verification Tests/Powertrain Verification Test.
No
-
Replace the Fuel Pump Module.
-
Perform the POWERTRAIN VERIFICATION TEST. See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code
Tests and Associated Procedures/Verification Tests/Powertrain Verification Test.
5. (A109) FUEL PUMP RELAY OUTPUT CIRCUIT OPEN
1. Turn the ignition off.
2. Remove the Fuel Pump Relay from the IPM.
3. Disconnect the Fuel Pump Module harness connector.
4. Measure the resistance of the (A109) Fuel Pump Relay Output circuit from the relay connector to the fuel pump module connector.
Is the resistance below 5.0 Ohms?
Yes
-
Replace the Fuel Pump Relay.
-
Perform the POWERTRAIN 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 open in the (A109) Fuel Pump Relay Output circuit.
-
Perform the POWERTRAIN VERIFICATION TEST. See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code
Tests and Associated Procedures/Verification Tests/Powertrain Verification Test.
