2010 Dodge or Ram Truck RAM 1500 Truck 2WD V8-5.7L Vehicle > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pressure > Testing and Inspection > Component Tests and General Diagnostics CHECKING THE FUEL DELIVERY SYSTEM CHECKING THE FUEL DELIVERY SYSTEM For a complete wiring diagram, refer to the Wiring Information. 1. FUEL PUMP OPERATION 1. Ignition on, engine not running. 2. With a scan tool, actuate the Fuel System test. NOTE: It may be necessary to use a mechanics stethoscope in the next step. 3. Listen for fuel pump operation at the fuel tank. Does the Fuel Pump operate? - Go To 2 - Go To 5 CAUTION: Stop All Actuations. https://my.alldata.com/repair/#/repair/article/47870/component/3386/itype/383/nonstandard/1139792 1/5
2. FUEL PRESSURE 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. 2. Install Fuel Pressure Decay Tester 8978A at the engine. 3. Ignition on, engine not running. 4. With 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). Choose a conclusion that best matches your fuel pressure reading. Below Specification - Go To 3 Within Specification - Test Complete. Above Specification - Replace the fuel filter/fuel pressure regulator. CAUTION: Stop All Actuations. 3. RESTRICTED FUEL SUPPLY LINE 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. https://my.alldata.com/repair/#/repair/article/47870/component/3386/itype/383/nonstandard/1139792 2/5
2. Disconnect the Fuel Pressure Decay Tester 8978A. 3. Raise the vehicle on a hoist, and disconnect the fuel pressure line at the fuel pump module. 4. Install the Fuel Pressure Decay Tester 8978A between the fuel supply line and the fuel pump module. 5. Ignition on, engine not running. 6. With 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). Is the fuel pressure within specification now? - Repair/replace fuel supply line as necessary. - Go To 4 CAUTION: Stop All Actuations. 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. 2. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Is the Fuel Inlet Strainer plugged? - Replace the Fuel Pump Inlet Strainer. https://my.alldata.com/repair/#/repair/article/47870/component/3386/itype/383/nonstandard/1139792 3/5
- Replace the Fuel Pump Module. 5. (N1) FUEL PUMP RELAY OUTPUT CIRCUIT 2. Disconnect the TIPM C6 harness connector. 3. Disconnect the Fuel Pump Module harness connector. 4. Using a 12-volt test light connected to ground, probe the (N1) Fuel Pump Control Output circuit at the Fuel Pump harness connector. NOTE: Make sure the test light is probing the circuit before actuating the Fuel Pump or a DTC may set and not allow the actuation. 5. With a scan tool, actuate the Fuel Pump Module. https://my.alldata.com/repair/#/repair/article/47870/component/3386/itype/383/nonstandard/1139792 4/5
Does the test light illuminate brightly during the actuation? - Replace the Fuel Pump Module. - Repair the open or short to ground in the (N1 Fuel Pump Control Output circuit. https://my.alldata.com/repair/#/repair/article/47870/component/3386/itype/383/nonstandard/1139792 5/5