Visual and Physical Inspection
Inspect the following items
- The control module grounds for being clean, tight, and in their proper location.
- The vacuum hoses for splits, kinks, and proper connections, as shown on the Vehicle Emission Control Information label.
- The wiring for the following items: Proper connections Pinches Cuts
- Inspect for the installation of any Power Enhancing Devices. It may be necessary to remove these items for proper diagnosis.
- The following symptom tables contain groups of possible causes for each symptom. The order of these procedures is not important. If the scan tool readings do not indicate the problems, then proceed in a logical order, easiest to inspect or most likely to cause first. In order to determine if a specific vehicle is using a particular system or component, refer to «Engine Controls Schematics»(ref-184140-S37826751162005082200000) for an application.
Circuit Description
Voltage is supplied to the malfunction indicator lamp (MIL). The engine control module (ECM) turns the MIL ON by grounding the MIL control circuit. There should be a steady MIL with the ignition ON and the engine OFF.
Ignition voltage is supplied to the malfunction indicator lamp (MIL). The engine control module (ECM) turns the MIL ON by grounding the MIL control circuit.
Diagnostic Aids
If the problem is intermittent, refer to Intermittent Conditions .
The Engine Cranks but Does Not Run diagnostic table is an organized approach to identifying a condition that causes an engine not to start. The Engine Cranks but Does Not Run diagnostic table directs the service technician to the appropriate system diagnosis.
The Engine Cranks But Does Not Run diagnostic table assumes the following
- The batteries are completely charged. Refer to «Battery Inspection/Test (Non-HP2)»(ref-184152-S28156847602005082200000) or «Battery Inspection/Test (HP2)»(ref-184152-S41639296552005082200000) in Engine Electrical.
- The cranking speed is within specifications. Refer to «Engine Cranks Slowly»(ref-184152-S21837754192005082200000) in Engine Electrical.
- There is adequate fuel in the fuel tanks.
If the cause of an engine cranks but will not run condition has not been found, inspect for the following conditions
- Hard starting only in cold ambient temperatures. These may cause an intermittent condition that may not occur in the service bay: Fuel heater inoperative, refer to «Fuel Heater Inoperative»(ref-184195-S37712293872005082200000) . Ice blockage at the fuel pickup in the fuel tank. This will be a high vacuum in the supply lines while cranking, and the problem will disappear after the vehicle is brought in the service bay. It may also exhibit a start and stall condition or a starting condition with no acceleration.
- The correct cranking speed is 100 RPM cold and 180 RPM hot.
- Water or foreign material in fuel system
- A basic engine problem
- More than 1 ohm of resistance in the ignition 1 voltage circuit to the fuel injection control module may cause a crank no start condition.
- Low engine coolant level may cause the engine to shut down.
The EDU/IGN 1 relay is normally an open relay. The relay armature is held in the open position by spring tension. When the ignition switch is turned to the Run or Start position, current will flow through the relay coil. A wire connected to the other end of the relay coil completes the path to ground through the engine control module (ECM). The electromagnetic field created by the relay coil overcomes the spring tension and moves the armature, allowing the contacts to close. The closed relay contacts allow current to flow from the battery to the following fuses
- The ECM RPV fuse
- The EDU fuse
When the ignition switch is turned to the OFF position, the electromagnetic field collapses. This action allows the spring tension to move the armature away from the relay contacts, which interrupts current flow to the fuses.
If the EDU/IGN 1 relay fails to close, the engine will crank but will not run. The class 2 communications will be available with the use of a scan tool.
The EDU/IGN 1 relay table assumes that the vehicle battery is fully charged. Refer to Battery Inspection/Test (Non-HP2) or Battery Inspection/Test (HP2) in Engine Electrical.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Power Distribution Schematics , Ground Distribution Schematics in Wiring Systems and Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) 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 |
| 2 | Turn ON the ignition, with the engine OFF. Remove the underhood fuse block cover. Probe the following fuses with a test lamp that is connected to a good ground. The ECM RPV fuse The EDU fuse Refer to Probing Electrical Connectors and Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate on at least one test point of each fuse? | Go to Step 3 | Go to Step 9 |
| 3 | Turn OFF the ignition. Probe both test points of the EDU fuse with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors and Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate on either test point of the fuse? | Go to Step 4 | Go to Step 24 |
| 4 | Turn OFF the ignition. Remove the EDU/IGN 1 relay from the underhood fuse block with the J 43244 Relay Puller Pliers and Relay Replacement (Within an Electrical Center) or Relay Replacement (Attached to Wire Harness) in Wiring Systems. Probe the coil ground circuit of the EDU/IGN 1 relay at the underhood fuse block with a test lamp that is connected to battery positive. Refer to Probing Electrical Connectors and Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate? | Go to Step 5 | Go to Step 7 |
| 5 | Turn OFF the ignition. Disconnect the negative battery cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure (Single Battery) or Battery Negative Cable Disconnect/Connect Procedure (Auxiliary Battery) in Engine Electrical. Disconnect the underhood fuse block electrical connector that contains the ground wire for the EDU/IGN 1 relay. Disconnect the engine control module (ECM) electrical connector that contains the ground wire for the EDU/IGN 1 relay. Test the coil ground wire of the EDU/IGN 1 relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 24 | Go to Step 6 |
| 6 | Test the EDU/IGN 1 relay coil ground bus bar circuit of the underhood fuse block for a short to ground. Refer to Circuit Testing in Wiring Systems. Did you find a condition? | Go to Step 23 | Go to Step 20 |
| 7 | Test the relay load bus bar circuit of the underhood fuse block between the EDU/IGN 1 relay and the fuses to the circuit components for a short to battery positive voltage. Refer to Circuit Testing in Wiring Systems. Did you find a condition? | Go to Step 23 | Go to Step 8 |
| 8 | Turn OFF the ignition. Remove the following fuses from the underhood fuse block: The ECM RPV fuse The EDU fuse Probe both fuse terminals for each fuse in the underhood fuse block with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors and Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate at any of the fuse terminals? | Go to Diagnostic System Check - Engine Electrical in Engine Electrical | Go to Step 21 |
| 9 | Turn ON the ignition, with the engine OFF. Probe both test points of the 20-amp ECM B fuse in the underhood fuse block with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors and Troubleshooting with a Test Lamp in Wiring Systems Does the test lamp illuminate on both test points of the fuse? | Go to Step 13 | Go to Step 10 |
| 10 | Does the test lamp illuminate on one test point of the 20-amp ECM B fuse? | Go to Step 11 | Go to Step 12 |
| 11 | Test the battery positive voltage bus bar circuit of the underhood fuse block between the 20-amp ECM B fuse and the EDU/IGN 1 relay for a short to ground. Refer to Circuit Testing in Wiring Systems. Did you find a condition? | Go to Step 23 | Go to Step 21 |
| 12 | Turn OFF the ignition. Probe the mounting stud for the battery positive cable at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors and Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate? | Go to Step 23 | Go to Diagnostic System Check - Engine Electrical in Engine Electrical |
| 13 | Turn OFF the ignition. Remove the EDU/IGN 1 relay with the J 43244 from the underhood fuse block. Probe the battery positive voltage circuit of the EDU/IGN 1 relay at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors and Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate? | Go to Step 14 | Go to Step 23 |
| 14 | Turn ON the ignition. Probe the ignition 1 voltage circuit of the EDU/IGN 1 relay at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors and Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate? | Go to Step 15 | Go to Step 23 |
| 15 | Turn ON the ignition with the engine OFF. Probe the coil ground circuit of the EDU/IGN 1 relay at the underhood fuse block with a test lamp that is connected to a battery positive voltage. Refer to Probing Electrical Connectors and Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate? | Go to Step 18 | Go to Step 16 |
| 16 | Turn OFF the ignition. Disconnect the negative battery cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure (Single Battery) or Battery Negative Cable Disconnect/Connect Procedure (Auxiliary Battery) in Engine Electrical. Disconnect the underhood fuse block electrical connector that contains the ground wire for the EDU/IGN 1 relay. Disconnect the engine control module (ECM) electrical connector that contains the ground wire for the EDU/IGN 1 relay. Test the coil ground wire of the EDU/IGN 1 relay for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 24 | Go to Step 17 |
| 17 | Test the EDU/IGN 1 relay coil ground bus bar circuit of the underhood fuse block for a high resistance or an open. Refer to Circuit Testing in Wiring Systems. Did you find a condition? | Go to Step 23 | Go to Step 20 |
| 18 | Turn OFF the ignition. Jumper the EDU/IGN 1 relay battery positive voltage circuit and the EDU/IGN 1 relay load circuit together at the underhood fuse block with a 20-amp fused jumper wire. Refer to Using Fused Jumper Wires in Wiring Systems. Probe the following fuses with a test lamp that is connected to a good ground: The ECM RPV fuse The EDU fuse Refer to Probing Electrical Connectors and Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate on at least one test point of each fuse? | Go to Step 19 | Go to Step 23 |
| 19 | Test for an intermittent and for a poor connection at the underhood fuse block EDU/IGN 1 relay connector location. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find a condition? | Go to Step 23 | Go to Step 21 |
| 20 | Test for an intermittent and for a poor connection at the ECM connectors. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find a condition? | Go to Step 24 | Go to Step 22 |
| 21 | Replace the EDU/IGN 1 relay. Refer to Relay Replacement (Within an Electrical Center) or Relay Replacement (Attached to Wire Harness) in Wiring Systems. Did you complete the replacement? | Go to Step 24 | |
| 22 | Replace the ECM. Refer to Engine Control Module (ECM) Replacement . Did you complete the replacement? | Go to Step 24 | |
| 23 | Replace the underhood fuse block assembly. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Did you complete the replacement? | Go to Step 24 | |
| 24 | Replace any open fuses. Turn the ignition OFF for 30 seconds. Attempt to start the engine. Does the engine start and run? | Go to Step 25 | Go to Engine Cranks but Does Not Run |
| 25 | Clear the DTCs with a scan tool. Operate the vehicle for 5 minutes. Does a DTC set during this ignition cycle? | Go to Diagnostic Trouble Code (DTC) Type(s) | System OK |
Ignition Relay Diagnosis
Fuel Pressure Regulator Diagnosis
The Fuel Pressure Regulator graphing procedure offers valuable information on regulator performance by comparing desired and actual fuel rail pressure. An almost perfect comparison between actual rail pressure and desired rail pressure is found on a fairly new, low mileage engine. A minor ripple is acceptable behavior for the fuel rail pressure regulator and is seen on high mileage engines. A "shark tooth" fluctuation in actual fuel rail pressure indicates a sticking pressure regulator.
- Set up the following Min/Max ranges for graphing the fuel rail pressure on the scan tool. Engine Speed Min/Max range is 0-1,000 RPM. Actual Fuel Rail Pressure Min/Max range is 1-160 MPa. Desired Fuel Rail Pressure Min/Max is 1-160 MPa.
- Start and idle the engine.
- Observe the live plot for sharp changes or shark tooth pattern in the Actual Fuel Rail Pressure while performing the following actions: Idling the engine Shifting the transmission from Park to Drive and back to Park Turning the steering from left stop position to right stop position Turning the air conditioning ON and OFF
- If there is a violent fluctuation in the Actual Fuel Rail Pressure, as seen in the surging graph below, replace the fuel pressure regulator. Refer to «Fuel Pressure Regulator Replacement»(ref-184140-S23412691522005082200000) .
Scheme 458
| Callout | Component Name |
|---|---|
| 1 | Engine Speed |
| 2 | Actual Fuel Rail Pressure |
| 3 | Desired Fuel Rail Pressure |
Scheme 459
| Callout | Component Name |
|---|---|
| 1 | Engine Speed |
| 2 | Actual Fuel Rail Pressure |
| 3 | Desired Fuel Rail Pressure |
Scheme 460
| Callout | Component Name |
|---|---|
| 1 | Engine Speed |
| 2 | Actual Fuel Rail Pressure |
| 3 | Desired Fuel Rail Pressure |
The following conditions may cause an air leak into the fuel supply system
- Deformed or cut O-rings at the fuel supply line connections
- Improperly seated fuel supply line fittings
- Porous or weathered rubber fuel supply lines
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | IMPORTANT: Ensure that a sufficient amount of fuel is in the fuel tank to run the vehicle. Install the J 44638 Vacuum Gage to the fuel system service port on the right front side of the engine. Prime the fuel system until 10 psi is indicated on the J 44638 . IMPORTANT: It may be necessary to remove engine components for the visual inspections. Visually inspect the following items for restrictions or leaks: Fuel injector control module fuel line connections Hoses and lines that are flattening when the engine is running, or have kinks that would restrict the flow of fuel Fuel leaks between the fuel filter/heater element housing and the fuel injection pump Did you find and correct the condition? | Go to Step 21 | Go to Step 2 |
| 2 | Does the fuel system pressure drop below 2 psi in less than 1 minute? | Go to Step 12 | Go to Step 3 |
| 3 | Disconnect the fuel supply line at the engine. Refer to Quick Connect Fitting(s) Service (Metal Collar) . Cap off the fuel supply pipe on the engine with a rubber plug and clamp. Disconnect the fuel return line at the engine. Refer to Quick Connect Fitting(s) Service (Metal Collar) . Install a J 23738-A Mityvac on the fuel return pipe on the engine. Apply at least 25 inches Hg of vacuum to the fuel return pipe and wait for at least 1 minute for the system to stabilize. Repeat this step 6 additional times. Does the J 23738-A gage indicate that vacuum dropped below 8 inches Hg of vacuum within 10 minutes? | Go to Step 7 | Go to Step 4 |
| 4 | Connect the fuel supply line at the engine. Disconnect the chassis fuel supply line from the fuel sender at the fuel tank. Refer to Quick Connect Fitting(s) Service (Metal Collar) . Plug the chassis fuel supply line. Apply at least 25 inches Hg of vacuum to the fuel return pipe with the J 23738-A and wait more than 1 minute for the system to stabilize. Repeat the previous step 10 times. Observe the J 23738-A . Does the vacuum drop below 8 Hg of vacuum within 10 minutes? | Go to Step 15 | Go to Step 5 |
| 5 | Reconnect the return line at the engine. Install a transparent hose between the fuel injection control module (FICM) outlet and the fuel filter inlet with a vertical loop to observe the incoming fuel for air bubbles. Install all components and lines that were previously disconnected or removed. Prime the fuel system 30 times to remove the air from the fuel hoses. Attempt to start the engine. Did the engine start? | Go to Step 6 | Go to Step 12 |
| 6 | Run the engine for at least 10 minutes to allow the fuel system to stabilize, and purge any air from the system. Observe the fuel in the transparent hose. Are there any air bubbles entering the transparent hose? | Go to Step 10 | Go to Step 21 |
| 7 | Disconnect the fuel outlet hose from the outlet pipe of the fuel filter/heater element housing. Open the drain on the fuel filter/heater element housing and drain the fuel into a suitable container. Close the drain. Install a J 23738-A on the outlet port of the fuel filter/heater element housing. Apply 15 inches Hg of vacuum to the fuel pipe and observe the gage. Does the vacuum drop? | Go to Step 13 | Go to Step 8 |
| 8 | Connect the fuel supply line at the engine. Remove the J 23738-A from the outlet port of the fuel filter assembly and install it on the fuel outlet hose. Remove the supply hose from the fuel injection pump and plug the hose. Apply 15 inches Hg of vacuum and observe the reading. Does the vacuum drop? | Go to Step 16 | Go to Step 9 |
| 9 | Disconnect the fuel injection pump return hose. Cap off the fuel return pipe on the fuel injection pump with a rubber plug, and clamp the plug. Install a J 23738-A to the fuel inlet pipe of the fuel injection pump. Apply 20 inches Hg of vacuum and observe the reading. Does the vacuum drop? | Go to Step 18 | Go to Step 17 |
| 10 | Remove the front fuel tank. Refer to Fuel Tank Replacement (Pickup) or Fuel Tank Replacement (Cab/Chassis - Front) or Fuel Tank Replacement (Cab/Chassis - Rear) . Remove the fuel sender from the fuel tank. Refer to Fuel Sender Assembly Replacement . Remove the strainer from the fuel sender and plug the bottom end of the pickup tube. Install a J 23738-A to the upper end of the pickup tube. Apply 15 inches Hg of vacuum and observe the reading. Does the vacuum drop? | Go to Step 20 | Go to Step 11 |
| 11 | Install the fuel sender, fuel tank and connect all fuel system connections that were previously disconnected. Refer to Fuel Sender Assembly Replacement and Fuel Tank Replacement (Pickup) or Fuel Tank Replacement (Cab/Chassis - Front) or Fuel Tank Replacement (Cab/Chassis - Rear) . Prime the fuel system 30 times, or until fuel pressure is 10 psi, to remove the air from the fuel system. Air will be forced out of the system within 2 minutes. Start and run the engine. Observe the fuel entering the transparent hose for air bubbles. Are any air bubbles present in the transparent hose? | Go to Diagnostic Aids | Go to Step 21 |
| 12 | Prime the fuel system 30 times, or until fuel pressure is 10 psi, to remove the air from the fuel system. Air will be forced out of the system within 2 minutes. Remove the hose from the fuel filter/heater element housing outlet fitting and plug the hose. Verify that the J 44638 is installed. Remove the ignition 1 relay. Crank the engine 2-3 times in 15-second intervals and observe the J 44638 . Does the J 44638 indicate more than 5 inches Hg of vacuum? | Go to Step 21 | Go to Step 18 |
| 13 | Disconnect the fuel supply line from the fuel filter/heater element housing port. Install the J 23738-A to the fuel supply line. Apply 15 inches Hg of vacuum and observe the reading. Does the vacuum drop? | Go to Step 14 | Go to Step 19 |
| 14 | Repair the air leak in the fuel supply pipe on the engine. Did you complete the repair? | Go to Step 21 | |
| 15 | Repair the air leak in the fuel supply line between the engine and the fuel tank sending unit. Did you complete the repair? | Go to Step 21 | |
| 16 | Repair the leak between the fuel filter/heater element housing outlet and the fuel injection pump inlet. Did you complete the repair? | Go to Step 21 | |
| 17 | Replace the fuel injection pump inlet supply hose. Refer to Fuel Hose Replacement - Fuel Injection Pump to Fuel Feed Block . Did you complete the replacement? | Go to Step 21 | |
| 18 | Replace the fuel injection pump. Refer to Fuel Injection Pump Replacement . Did you complete the replacement? | Go to Step 21 | |
| 19 | IMPORTANT: Before replacing the fuel filter/heater element housing, inspect the fuel vent screw for damage or cross threading. Replace the vent screw with O-ring if either condition is found. Replace the fuel filter/heater element housing. Refer to Fuel Filter/Heater Element Housing Replacement .Did you complete the replacement? | Go to Step 21 | |
| 20 | Replace the fuel tank sending unit. Refer to Fuel Sender Assembly Replacement . Did you complete the replacement? | Go to Step 21 | |
| 21 | Remove the transparent hose, if necessary, and attach any disconnected components or fuel lines. Clean any fuel spills. Prime the fuel system 30 times to remove the air in the fuel hoses. Start the engine. If the engine starts and stalls, prime fuel system an additional 30 times. Run the engine to ensure no fuel leaks exist. Is the customer concern corrected? | System OK | Go to Symptoms - Engine Controls |
| IMPORTANT |
|---|
| Ensure that a sufficient amount of fuel is in the fuel tank to run the vehicle. |
| IMPORTANT |
|---|
| It may be necessary to remove engine components for the visual inspections. |
| IMPORTANT |
|---|
| Before replacing the fuel filter/heater element housing, inspect the fuel vent screw for damage or cross threading. Replace the vent screw with O-ring if either condition is found. |
Fuel System Diagnosis
Bent or pinched fuel return lines on the engine can cause a restricted fuel return flow.
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | IMPORTANT: Do not apply more than the specified air pressure to the return line. Disconnect the return line at the engine. Refer to Quick Connect Fitting(s) Service (Metal Collar) . Remove the fuel filler cap. Apply 1 psi air at the fuel return line that leads back to the tank. Listen at the filler tube for air flowing from the tank. Did air flow from the filler tube? | Go to Step 6 | Go to Step 2 |
| 2 | Disconnect the return line at the fuel sender assembly. Retest using 1 psi at the fuel return line back to the tank. Did air flow from the return line? | Go to Step 3 | Go to Step 4 |
| 3 | Replace the fuel sender assembly. Refer to Fuel Sender Assembly Replacement . Did you complete the replacement? | Go to Step 6 | |
| 4 | Lift the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. Inspect the return line for restrictions between the fuel tank and engine. Did you find and correct the condition? | Go to Step 6 | Go to Step 5 |
| 5 | Replace the fuel return line between the engine and the fuel tank. Refer to Fuel Return Pipe Replacement . Did you complete the replacement? | Go to Step 6 | |
| 6 | Install and connect all components or fuel lines that were previously removed or disconnected. Operate the vehicle in order to verify the repairs. Did you correct the condition? | System OK | Go to Diagnostic Aids |
| IMPORTANT |
|---|
| Do not apply more than the specified air pressure to the return line. |
Fuel Return System Diagnosis
- The fuel return volumes vary based on the American Petroleum Institute (API) rating of the diesel fuel.
- A fuel injector may have high fuel return flow only at higher engine temperatures.
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Were you referred to this test from the Engine Cranks but Does Not Run diagnostic? | Go to Step 3 | Go to Step 2 |
| 2 | Remove the fuel return rubber hose from the rear of the left fuel rail and plug the hose to prevent fuel leakage. Install a section of rubber fuel hose on the fuel pressure relief valve connection and place it in a clean fuel container. Start and idle the engine. Command the fuel rail pressure to 160 MPa with a scan tool. Observe the fuel hose and container for fuel leakage. Did fuel flow into the container? | Go to Step 12 | Go to Step 4 |
| 3 | IMPORTANT: If you were not referred to this test from another diagnostic, do not perform this procedure. Only perform this test when the fuel is more than 18°C (65°F). Remove the air duct from the air cleaner assembly and the turbo inlet. Remove the fuel return rubber hose from the rear of the left fuel rail and plug the hose to prevent fuel leakage. Remove the relay that supplies ignition 1 voltage to the fuel injection control module (FICM). Crank the engine for 15 seconds while observing the fuel pressure relief valve hose connection for fuel leakage. Did fuel leak from the fuel pressure relief valve at the hose connection? | Go to Step 12 | Go to Step 4 |
| 4 | IMPORTANT: The engine cranking speed must be more than 150 RPM during the cranking portion of this test. Always replace the fuel return hose retaining clips on the fuel injectors with new clips after removing. Remove the relay that supplies the ignition 1 voltage to the FICM, if it was not previously removed. Remove the fuel return hose from the fuel injectors of the right cylinder bank. Refer to Fuel Injector Return Pipe Replacement - Right . Connect the yellow hoses from the J 45873 Fuel Return Volume Test Kit to the J 45873-30 Fuel Injector Test Adapters. Connect the J 45873-30 with yellow hoses to each fuel injector return port of the right cylinder bank, and install the retaining clips. Install the 4 yellow hoses in the J 45873 graduated cylinders in numerical order. Connect the fuel return hoses to the J 45873-30 to prevent leakage. Crank the engine in 15-second intervals, with 1 minute cooling time between intervals, until fuel starts to flow into all of the graduated cylinders. Elevate the 4 hoses to retain the fuel in the hoses, and empty the 4 graduated cylinders into a suitable container. Install the 4 yellow hoses in the J 45873 graduated cylinders in numerical order. Crank the engine for 15 seconds. Measure the quantity of fuel in each of the graduated cylinders. Refer to Fuel System Specifications for the desired quantities. Were any of the fuel quantities more than the specified values? | Go to Step 5 | Go to Step 6 |
| 5 | Remove the fuel feed pipes from any fuel injectors that have high return flow and install the EN 47589 Fuel Pressure Adapter Cap to the fuel rail outlets. Elevate the 4 hoses to retain the fuel in the hoses, and empty the 4 graduated cylinders into a suitable container. Install the 4 yellow hoses in the graduated cylinders in numerical order. Crank the engine for 15 seconds. Using the Retesting Fuel Injector Return Flow Values table, measure the quantity of fuel in each of the graduated cylinders. Refer to Fuel System Specifications for the desired quantities. Remove the fuel feed pipes from any uncapped fuel injectors that have high return flow and install the EN 47589 to the fuel rail outlets. Did you complete the action? | Go to Step 6 | |
| 6 | IMPORTANT: The engine cranking speed must be more than 150 RPM during the cranking portion of this test. Always replace the fuel injector return hose retaining clip. Remove the fuel return hoses from the fuel injectors of the left cylinder bank. Refer to Fuel Injector Return Pipe Replacement -Left . Connect the yellow hoses from the to the J 45873-30. Connect the J 45873-30 with yellow hoses to each fuel injector return port of the left cylinder bank, and install the retaining clips. Connect the fuel return hoses to the J 45873-30 to prevent leakage. Crank the engine in 15-second intervals, with 1 minute cooling time between intervals, until fuel starts to flow into all of the graduated cylinders. Elevate the 4 hoses to retain the fuel in the hoses, and empty the 4 graduated cylinders into a suitable container. Install the 4 yellow hoses in the graduated cylinders in numerical order. Crank the engine for 15 seconds. Measure the quantity of fuel in each of the graduated cylinders. Refer to Fuel System Specifications for the desired quantities. Were any of the fuel quantities more than the specified values? | Go to Step 8 | Go to Step 7 |
| 7 | Were any fuel injector lines capped off during either cylinder bank testing? | Go to Step 10 | Go to Step 11 |
| 8 | Remove the fuel feed pipes from any fuel injectors that have high return flow and install the EN 47589 to the fuel rail outlets. Elevate the 4 hoses to retain the fuel in the hoses, and empty the 4 graduated cylinders into a suitable container. Install the 4 yellow hoses in the graduated cylinders in numerical order. Crank the engine for 15 seconds. Using the Retesting Fuel Injector Return Flow Valves table, measure the quantity of fuel in each of the graduated cylinders. Refer to Fuel System Specifications for the desired quantities. Were the fuel quantities more than the specified value at the uncapped fuel injectors? | Go to Step 9 | Go to Step 10 |
| 9 | Repeat the fuel injector return flow test with capping until no fuel injectors have high return fuel flow. Did you complete the action? | Go to Step 10 | |
| 10 | Replace the fuel injectors that had capped off lines. Refer to Fuel Injector Replacement (Left) or Fuel Injector Replacement (Right) . Install all disconnected and removed fuel system components. Start and idle the engine. You may have to prime the fuel system before the engine will start. Command the fuel pressure control to 160 MPa with a scan tool. Is the fuel pressure more than 145 MPa? | Go to Step 13 | Go to Step 11 |
| 11 | Replace the fuel injection pump. Refer to Fuel Injection Pump Replacement . Did you complete the replacement? | Go to Step 13 | |
| 12 | Replace the fuel pressure relief valve. Refer to Fuel Pressure Relief Valve Replacement . Did you complete the replacement? | Go to Step 13 | |
| 13 | IMPORTANT: The fuel system may have to be primed before starting the engine. Install and connected all fuel system components that were previously removed or disconnected. Operate the vehicle in order to verify the repairs. Did you correct the condition? | System OK | Go to Symptoms - Engine Controls |
| IMPORTANT |
|---|
| If you were not referred to this test from another diagnostic, do not perform this procedure. Only perform this test when the fuel is more than 18°C (65°F). |
| IMPORTANT |
|---|
| The engine cranking speed must be more than 150 RPM during the cranking portion of this test. Always replace the fuel return hose retaining clips on the fuel injectors with new clips after removing. |
| IMPORTANT |
|---|
| The engine cranking speed must be more than 150 RPM during the cranking portion of this test. Always replace the fuel injector return hose retaining clip. |
| IMPORTANT |
|---|
| The fuel system may have to be primed before starting the engine. |
Fuel System Diagnosis - High Pressure Side
The Fuel Injector Balance Test is performed when a misfire, knock, excessive smoke, or rough running condition exists with no electrical diagnostic trouble codes (DTCs). During the Cylinder Power Balance portion of the test, the engine control module (ECM) turns OFF individual injectors while the engine is running and the scan tool displays engine RPM. The ECM adjusts for the drop in engine speed, so the power contribution of each cylinder must be felt by the technician. If a fuel injector is turned OFF and there is a different power contribution observed when compared to the other cylinders, that cylinder is identified with the complaint. If the customer complaint occurs during idle or during off-idle tip in acceleration, the balance rates are used to identify the cylinder with a fault related to the fuel injector or engine compression. If a fuel injector is turned OFF and the engine noise or smoke disappears, that cylinder has a fuel injector or engine compression condition.
The Fuel Injector Balance Test is performed when a misfire, knock, excessive smoke, or rough running condition exists with no electrical diagnostic trouble codes (DTCs). During the Cylinder Power Balance portion of the test, the engine control module (ECM) turns OFF individual injectors while the engine is running and the scan tool displays engine RPM. The ECM adjusts for the drop in engine speed, so the power contribution of each cylinder must be felt by the technician. If a fuel injector is turned OFF and there is a different power contribution observed when compared to the other cylinders, that cylinder is identified with the complaint. If the customer complaint occurs during idle or during off-idle tip in acceleration, the balance rates are used to identify the cylinder with a fault related to the fuel injector or engine compression. If a fuel injector is turned OFF and the engine noise or smoke disappears, that cylinder has a fuel injector or engine compression condition.
Fuel Tank Leak Test
The diagnosis of fuel odor may be a condition of a leaking fuel tank, filler neck or filler cap. A defective filler cap, a plugged or pinched vent pipe can cause a collapsed fuel tank. Loose mounting straps or foreign material in tank may be the cause of a rattle at the fuel tank.
Contaminants-in-Fuel Diagnosis
Fungi and other microorganisms can survive and multiply in diesel fuel if water is present. The fungi can be present in any part of the fuel handling system. These fungi grow into long strings and will form into large globules. The growths appear slimy and are usually black, green, or brown. The fungi may grow anywhere in the fuel but are most plentiful where diesel fuel and water meet. As the fuel is agitated, when service station tanks are being filled, fungi are distributed throughout the tank and may be pumped into a vehicle.
Fungi use the fuel as their main energy supply and need only trace amounts of water and minerals. As they grow and multiply, they change fuel into water, sludge, acids, and products of metabolism. The most common symptom is fuel filter plugging, however various metal fuel system components including fuel sender assembly, pipes, fuel injectors, and fuel injection pump can corrode.
| CAUTION | Avoid physical contact with the biocides in order to avoid personal injury. |
If fungi have caused fuel system contamination, use a diesel fuel biocide to sterilize the fuel system. Do not exceed the dosage recommended on the label. Discontinue the use of a biocide when towing a trailer. It is permissible to have biocide in the fuel when starting to tow, but do not add any biocide while towing.
Steam cleaning may be necessary if most of the fungus growth cannot be removed with biocides.
The presence of water or gasoline in diesel fuel may also cause injection pump and fuel injector damage.
This procedure checks for the presence of water and gasoline in diesel fuel that may cause fuel injection pump and fuel injector damage.
Remove and inspect the fuel filter.
- If water, gasoline or fungi/bacteria are not present, end the inspection.
- If water or fungi/bacteria are present, go to Cleaning Water from the Fuel System. Refer to «Fuel System Cleaning»(ref-184140-S11943982532005082200000) .
- If gasoline is present, go to Cleaning Gasoline from the Fuel System. Refer to «Fuel System Cleaning»(ref-184140-S11943982532005082200000) .
Inspection/Maintenance (I/M) System DTC Table
| System | DTCs Required to Set System Status to YES |
|---|---|
| EGR | DTC P0401 |
| Misfire Monitoring | DTC P0300 (Federal Emissions) or DTC P0300 (California Emissions) DTC P0301-P0308 (Federal Emissions) or DTC P0301-P0308 (California Emissions) |
Inspection/Maintenance (I/M) System DTC Table
Conditions for Running
Cold start
- The battery voltage is between 11-18 volts.
- The engine coolant temperature (ECT) is between 60-96.75°C (140-206.2°F).
- The intake air temperature (IAT) is more than 5.25°C (41.5°F).
- The barometric pressure (BARO) is more than 74 kPa.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| 1 | Did you perform the Inspection/Maintenance (I/M) System Check? | Go to Step 2 | Go to Inspection/Maintenance (I/M) System Check | |
| 2 | Ensure the vehicle is within the Conditions for Running specified in the supporting text. Turn OFF all of the accessories, e.g., A/C, blower fan, etc. Set the vehicle parking brake. Verify the transmission is in PARK for automatic transmissions and NEUTRAL for manual transmissions. Start and allow the engine to idle for the specified time. Observe the I/M System Status with a scan tool. Did both of the I/M System Status indicators update to YES? | 2 minutes | Go to Step 3 | Go to the I/M System Set Procedure for the systems that did not update to YES |
| 3 | Observe the Emission Related DTC portion of the I/M System Status with a scan tool. Does the scan tool indicate any Emission Related DTCs set? | Go to Diagnostic Trouble Code (DTC) List | System OK |
Inspection/Maintenance (I/M) Complete System Set Procedure
- The barometric pressure (BARO) is more than 74 kPa.
- The engine coolant temperature (ECT) is between 60-96.75°C (140-206.2°F).
- The intake air temperature (IAT) is more than 5.25°C (41.5°F).
- The battery voltage is between 11-18 volts.
If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the system set procedure. If any DTCs do not run and no DTC is set, review the appropriate scan tool data list and service information. This will give an indication of why the DTCs do not run. Some may abort due to changes in the conditions while running. For example, changes in engine load such as a cooling fan or A/C compressor clutch turning ON, may cause a DTC to abort. If the EGR I/M System Status does not update to YES, the procedure can be repeated until a YES status is achieved.
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Did you perform the Inspection/Maintenance (I/M) System Check? | Go to Step 2 | Go to Inspection/Maintenance (I/M) System Check |
| 2 | Ensure that the vehicle is within the Conditions for Running specified in the supporting text. Turn OFF all of the accessories, e.g., A/C, blower fan, etc. Start and allow the engine to idle for 2 minutes. Observe the I/M System Status display with a scan tool. Did the Exhaust Gas Recirculation (EGR) System Status update to YES? | Go to Step 5 | Go to Step 3 |
| 3 | Observe the DTC Information with a scan tool. Does the scan tool indicate any failed DTCs? | Go to Diagnostic Trouble Code (DTC) List | Go to Step 4 |
| 4 | Refer to Inspection/Maintenance (I/M) System DTC Table to determine which DTCs are required to run in order to update the EGR I/M System Status to YES. Observe the Not Ran Since Code Cleared display with a scan tool. Determine which of the DTCs required for a YES status has not run. Enter the DTC number in the Specific DTC menu of the scan tool. Operate the vehicle within the Conditions for Running the DTC, located in the supporting text for the diagnostic table of the DTC. Repeat numbers 4 and 5 of this step for any additional required DTCs that have not run. Observe the I/M System Status display with a scan tool. Did the EGR System Status update to YES? | Go to Step 5 | Go to Diagnostic Aids |
| 5 | Observe the Emission Related DTC portion of the I/M System Status display with a scan tool. Does the scan tool indicate any Emission Related DTCs set? | Go to Diagnostic Trouble Code (DTC) List | System OK |
Inspection/Maintenance (I/M) Exhaust Gas Recirculation (EGR) System Set Procedure
The engine coolant temperature (ECT) is between 57-104°C (133-219°F).
If there is an impending failure, the system may require more time than was allotted in the system set procedure. If any DTCs do not run and DTC is set, review the appropriate scan tool data list and service information. This will give an indication of why the DTCs do not run. Some may abort due to changes in the conditions while running. For example, changes in engine load such as a cooling fan or A/C compressor clutch turning ON, may cause a DTC to abort. If the Misfire Monitoring I/M System Status does not update to YES, the procedure can be repeated until a YES status is achieved.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| 1 | Did you perform the Inspection/Maintenance (I/M) System Check? | Go to Step 2 | Go to Inspection/Maintenance (I/M) System Check | |
| 2 | Ensure the vehicle is within the Conditions for Running specified in the supporting text. Set the vehicle parking brake. Verify the transmission is in PARK for automatic transmissions and NEUTRAL for manual transmissions. Turn OFF all of the accessories, e.g., A/C, blower fan, etc. Start and allow the engine to idle for the specified time. Did the Misfire Monitoring I/M System Status update to YES? | 2 minutes | Go to Step 5 | Go to Step 3 |
| 3 | Observe the DTC information with a scan tool. Does the scan tool indicate any failed DTCs? | Go to Diagnostic Trouble Code (DTC) List | Go to Step 4 | |
| 4 | Refer to the Inspection/Maintenance (I/M) System DTC Table to determine which DTCs are required to run in order to update the Misfire Monitoring I/M System Status to YES. Observe the Not Ran Since Code Cleared parameter with a scan tool. Determine which of the DTCs required for a YES status has not run. Enter the DTC number in the Specific DTC menu of the scan tool. Operate the vehicle within the Conditions for Running the DTC, located in the supporting text for the diagnostic table of the DTC. Repeat numbers 4 and 5 of this step for any additional required DTCs that have not run. Observe the I/M System Status with a scan tool. Did the Misfire Monitoring System Status update to YES? | Go to Step 5 | Go to Diagnostic Aids | |
| 5 | Observe the Emission Related DTC portion of the I/M System Status with a scan tool. Does the scan tool indicate any Emission Related DTCs set? | Go to Diagnostic Trouble Code (DTC) List | System OK |
Inspection/Maintenance (I/M) Misfire Monitoring System Set Procedure
The fuel manager/filter assembly consists of the fuel heater, the water-in-fuel sensor, and a filter. The filter contains the coalescer, the device that combines small droplets of water into larger ones, and the filter/separator.
As the fuel enters the filter, the fuel passes through the fuel heater. The heater contains a thermostatic switch that opens or closes to turn the heater OFF or ON, depending on the temperature of the fuel.
The fuel then passes through the filter and the water coalescer, where the droplets of water in the fuel combine into larger drops that fall into the water reservoir in the filter. When fuel flows from the fuel manager/filter assembly to the injection pump, the fuel is clean and free of water.
The fuel heater is operated by a built-in thermostatic switch. The thermostatic switch completes the circuit for the fuel heater element when the thermostatic switch senses a temperature below 15.4°C (59.8°F).
The fuel filter/heater element housing consists of the fuel heater, the water-in-fuel sensor, and a filter.
As fuel enters the fuel filter/heater element housing, it first passes though the fuel heater. The heater contains a thermostatic switch that turns the heater ON and OFF, depending on the temperature of the fuel. When the temperature is below 8°C (46°F), the heater is turned ON. When the temperature is above 15°C (59°F), the heater is turned OFF.
The fuel then passes through the fuel filter and the water separator, where the droplets of water combine into larger drops, then fall into the water reservoir located in the bottom of the filter.
When fuel flows from the fuel filter/heater element housing to the fuel injection pump, the fuel is clean and free of water.