Description
The Engine Cranks but Does Not Run diagnostic table is an organized approach to identifying a condition that causes an engine to not start. The diagnostic table directs the service technician to the appropriate system diagnosis. The diagnostic table assumes the following conditions are met
- The battery is completely charged. Refer to «Battery Inspection/Test (Non-HP2)»(ref-238228-S06464573042006072400000) or «Battery Inspection/Test (HP2)»(ref-238228-S39090846112006072400000) in Engine Electrical.
- The engine cranking speed is acceptable. Refer to «Engine Cranks Slowly»(ref-238228-S20970594432006072400000) in Engine Electrical.
- There is adequate fuel in the fuel tank.
| Step | Action | Values | Yes | No |
|---|
| Schematic Reference: Engine Controls Schematics |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 | IMPORTANT: DO NOT allow the ignition switch to be interrupted during this step. Crank the engine for the specified amount of time.Does the scan tool display any DTCs that failed this ignition? | 15 seconds | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | Go to Step 3 |
| 3 | Does the scan tool display any body control module (BCM) vehicle theft deterrent (VTD) DTCs? | | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | Go to Step 4 |
| 4 | Turn OFF the ignition. Disconnect a spark plug wire from a spark plug. Install the J 26792 Spark Tester to the spark plug wire. Attach the clamp end of the spark tester to a good engine ground. Crank the engine while observing the spark tester. Repeat the test for the remaining cylinders. Does the spark tester spark on all cylinders? | | Go to Step 5 | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information |
| 5 | Turn ON the ignition, with the engine OFF. Probe both sides of the PCM 1 fuse located in the underhood electrical center with a test lamp connected to a good ground. Does the test lamp illuminate on at least one side of the fuse? | | Go to Step 6 | Go to Ignition Relay Diagnosis |
| 6 | Monitor the ignition 1 signal parameter with a scan tool. Is the ignition 1 signal parameter at the specified value? | B+ | Go to Step 7 | Go to Step 10 |
| 7 | Command the fuel pump ON with a scan tool. Does the fuel pump operate? | | Go to Step 8 | Go to Fuel Pump Electrical Circuit Diagnosis |
| 8 | Turn OFF the ignition. Install a fuel pressure gage. Refer to Fuel System Diagnosis . IMPORTANT: The fuel pump operates for about 2 seconds when the ignition is turned ON. The fuel pressure must be observed when the fuel pump is operating. Turn ON the ignition, with the engine OFF. Observe the fuel pressure while the fuel pump is operating. Is the fuel pressure within the specified range? | 385-425 kPa (55-62 psi) | Go to Step 9 | Go to Fuel System Diagnosis |
| 9 | Inspect for the following conditions: The engine coolant temperature (ECT) sensor is not close to the actual engine temperature. The duct work between the mass air flow (MAF) sensor and the throttle body for air leaks A restricted exhaust system - Refer to Restricted Exhaust in Engine Exhaust. A malfunctioning MAF sensor may cause a no start or a stall after a start. If you suspect this, disconnect the MAF sensor. The powertrain control module (PCM) will default to the speed density in order to calculate the engine load and the intake air flow. If disconnecting the MAF sensor corrects the condition and the connections are OK. Refer to DTC P0102 . The spark plugs for being gas fouled - Refer to Spark Plug Inspection . An engine mechanical failure that causes an engine not to start such as timing chain, low compression - Refer to Symptoms - Engine Mechanical and Engine Compression Test in Engine Mechanical. Compare the MAP/BARO parameters to another vehicle. The parameter values should be close to each other. Did you complete the action? | | Go to Step 13 | |
| 10 | Test the ignition 1 voltage circuit for an open or for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Replace the fuse if necessary. Did you find and correct the condition? | | Go to Step 13 | Go to Step 11 |
| 11 | Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | | Go to Step 13 | Go to Step 12 |
| 12 | Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | | Go to Step 13 | |
| 13 | Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Attempt to start the engine. Does the engine start the continue to run? | | Go to Step 14 | Go to Step 2 |
| 14 | Allow the engine to reach operating temperature. Observe the DTC information with a scan tool. Are there any DTCs that have not been diagnosed? | | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
| IMPORTANT |
|---|
| DO NOT allow the ignition switch to be interrupted during this step. |
| IMPORTANT |
|---|
| The fuel pump operates for about 2 seconds when the ignition is turned ON. The fuel pressure must be observed when the fuel pump is operating. |
Engine Cranks but Does Not Run
Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 2: Command both the ON and OFF states. Repeat the commands as necessary.
- 3: This step determines if the condition is located on the coil side or the switch side of the circuit.
- 4: This step verifies that the PCM is providing voltage to the fuel pump relay.
- 5: This step tests for an open in the ground circuit to the fuel pump relay.
- 6: This step determines if a voltage is constantly being applied to the fuel pump relay.
- 12: To gain access to the fuel pump connector, the fuel tank may need to be removed.
- 13: This step determines if the condition with the circuit is intermittent. If the fuse does not open, inspect the supply voltage circuit between the fuse and the fuel pump for an intermittent condition.
- 15: Use the same amperage fuse in the jumper as is used to protect the fuel pump circuit.
- 16: To gain access to the fuel pump connector, the fuel tank may need to be removed.
- 17: Inspect the ground connection for the fuel pump. Be certain all ground connections are clean and tight.
| Step | Action | Yes | No |
|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module (PCM) Connector End Views or Engine Controls Connector End Views |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. Command the fuel pump relay ON and OFF with a scan tool. Does the fuel pump turn ON and OFF? | Go to Diagnostic Aids | Go to Step 3 |
| 3 | Command the fuel pump relay ON and OFF with a scan tool. Do you hear a click when you command the fuel pump relay ON and OFF? | Go to Step 9 | Go to Step 4 |
| 4 | Turn OFF the ignition. Disconnect the fuel pump relay. Turn ON the ignition, with the engine OFF. Probe the control circuit of the fuel pump relay with a test lamp that is connected to a good ground. Command the fuel pump relay ON and OFF with a scan tool. Does the test lamp turn ON and OFF? | Go to Step 5 | Go to Step 6 |
| 5 | Connect a test lamp between the control circuit of the fuel pump relay and the ground circuit of the fuel pump relay. Command the fuel pump relay ON and OFF with a scan tool. Does the test lamp turn ON and OFF? | Go to Step 19 | Go to Step 22 |
| 6 | Does the test lamp remain illuminated with each command? | Go to Step 7 | Go to Step 8 |
| 7 | Test the control circuit of the fuel pump relay for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 27 | Go to Step 26 |
| 8 | Test the control circuit of the fuel pump relay for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 27 | Go to Step 20 |
| 9 | Turn ON the ignition, with the engine OFF. Does the fuel pump operate continuously? | Go to Step 10 | Go to Step 11 |
| 10 | Turn OFF the ignition. Disconnect the fuel pump relay. Turn ON the ignition, with the engine OFF. Does the fuel pump operate continuously? | Go to Step 21 | Go to Step 25 |
| 11 | Is the fuel pump fuse open? | Go to Step 12 | Go to Step 14 |
| 12 | Test the supply voltage circuit of the fuel pump for a grounded circuit between the fuel pump fuse and the fuel pump. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Replace the fuel pump fuse if necessary. Did you find and correct the condition? | Go to Step 27 | Go to Step 13 |
| 13 | Install all disconnected electrical components. Install a new fuel pump fuse. Turn ON the fuel pump with a scan tool. Is the fuel pump fuse open? | Go to Step 24 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems |
| 14 | Turn OFF the ignition. Disconnect the fuel pump relay. Turn ON the ignition, with the engine OFF. Probe the battery voltage circuit of the fuel pump relay switch with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 15 | Go to Step 23 |
| 15 | Connect a 20-amp fused jumper wire between the battery voltage circuit of the fuel pump relay switch and the supply voltage circuit of the fuel pump. Does the fuel pump operate? | Go to Step 19 | Go to Step 16 |
| 16 | Test the supply voltage circuit of the fuel pump for an open or high resistance between the fuel pump relay and the fuel pump. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 27 | Go to Step 17 |
| 17 | IMPORTANT: Inspect the ground circuit for being tight, corrosion on terminals, or damage to the wiring harness. Test the ground circuit of the fuel pump for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.Did you find and correct the condition? | Go to Step 27 | Go to Step 18 |
| 18 | Inspect for poor connections at the fuel pump. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 27 | Go to Step 24 |
| 19 | Inspect for poor connections at fuel pump relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 27 | Go to Step 25 |
| 20 | Inspect for poor connections at the harness connector of the powertrain control module (PCM). Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 27 | Go to Step 26 |
| 21 | Repair the supply voltage circuit of the fuel pump for a short to voltage. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 27 | |
| 22 | Repair the open fuel pump relay ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 27 | |
| 23 | Repair the battery voltage circuit of the fuel pump relay switch. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 27 | |
| 24 | IMPORTANT: Inspect for poor connections at the fuel pump, within the fuel tank, before replacing the fuel pump. Replace the fuel pump. Refer to Fuel Sender Assembly Replacement . Replace the fuel pump fuse if necessary. Did you complete the replacement? | Go to Step 27 | |
| 25 | Replace the fuel pump relay. Did you complete the replacement? | Go to Step 27 | |
| 26 | Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 27 | |
| 27 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
| IMPORTANT |
|---|
| Inspect the ground circuit for being tight, corrosion on terminals, or damage to the wiring harness. |
| IMPORTANT |
|---|
| Inspect for poor connections at the fuel pump, within the fuel tank, before replacing the fuel pump. |
Fuel Pump Electrical Circuit Diagnosis
System Description
The powertrain control module (PCM) enables the fuel pump relay when the ignition switch is turned ON. The PCM will disable the fuel pump relay within 2 seconds unless the PCM detects ignition reference pulses. The PCM continues to enable the fuel pump relay as long as ignition reference pulses are detected. The PCM disables the fuel pump relay within 2 seconds if ignition reference pulses cease to be detected and the ignition remains ON.
The Fuel System is a returnless on-demand design. The fuel pressure regulator is a part of the fuel sender assembly, eliminating the need for a return pipe from the engine. A returnless fuel system reduces the internal temperature of the fuel tank by not returning hot fuel from the engine to the fuel tank. Reducing the internal temperature of the fuel tank results in lower evaporative emissions.
The fuel tank stores the fuel supply. An electric turbine style fuel pump attaches to the fuel sender assembly inside the fuel tank. The fuel pump supplies high pressure fuel through the fuel filter and the fuel feed pipe to the fuel injection system. The fuel pump provides fuel at a higher rate of flow than is needed by the fuel injection system. The fuel pump also supplies fuel to a venturi pump located on the bottom of the fuel sender assembly. The function of the venturi pump is to fill the fuel sender assembly reservoir. The fuel pressure regulator, a part of the fuel sender assembly, maintains the correct fuel pressure to the fuel injection system. The fuel pump and sender assembly contains a reverse flow check valve. The check valve and the fuel pressure regulator maintain fuel pressure in the fuel feed pipe and the fuel rail in order to prevent long cranking times.
The numbers below refer to the numbers on the diagnostic table.
- 2: This step verifies that the fuel pump is operating.
- 4: This step tests for an internal fuel leak. If the fuel pressure drops during this test, then an internal loss of pressure is indicated.
- 7: This step tests for a loss of fuel pressure between the fuel feed pipe shut-off adapter and the fuel pump.
- 10: This step verifies that a circuit condition is not the cause of a fuel pressure concern. Inspect all fuel pump electrical circuits thoroughly.
- 11: This step tests for a leaking fuel injector, or fuel pressure regulator. If the fuel pressure remains constant during this test, the fuel injectors are not leaking fuel.
| Step | Action | Value(s) | Yes | No |
|---|
| Schematic Reference: Fuel System Description |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 | IMPORTANT: Inspect the fuel system for damage, or external leaks, before proceeding with this diagnostic. Turn ON the ignition, with the engine OFF. Command the fuel pump ON with a scan tool. Does the fuel pump operate? | | Go to Step 3 | Go to Fuel Pump Electrical Circuit Diagnosis |
| 3 | IMPORTANT: Verify there is adequate fuel in the fuel tank before proceeding with this diagnostic. Turn OFF the ignition. Turn OFF all accessories. CAUTION: Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel pressure gage. Place the towel in an approved container when the connection of the fuel pressure gage is complete. Install the J 34730-1A Fuel Pressure Gage. Place the bleed hose of the fuel pressure gage into an approved gasoline container. Turn ON the ignition, with the engine OFF. Command the fuel pump ON with a scan tool. Bleed the air out of the fuel pressure gage. IMPORTANT: It may be necessary to command the fuel pump ON several times in order to obtain the highest possible fuel pressure. DO NOT start the engine. Command the fuel pump ON with a scan tool. Observe the fuel pressure gage, with the fuel pump commanded ON. Is the fuel pressure within the specified value? | 384-425 kPa (56-62 psi) | Go to Step 4 | Go to Step 8 |
| 4 | IMPORTANT: The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize and remain constant. Observe the fuel pressure gage for 1 minute.Does the fuel pressure drop more than the specified value? | 34 kPa (5 psi) | Go to Step 7 | Go to Step 5 |
| 5 | Relieve the fuel pressure to the first specified value. Observe the fuel pressure gage for 5 minutes. Does the fuel drop more than the second specified value? | 69 kPa (10 psi) 14 kPa (2 psi) | Go to Step 12 | Go to Step 6 |
| 6 | Operate the vehicle within the conditions of the customer concern. Observe the fuel related parameters with a scan tool. Do any of the scan tool parameters indicate a lean condition? | | Go to Step 9 | Go to Symptoms - Engine Controls |
| 7 | Turn OFF the ignition. Relieve the fuel pressure. Refer to Fuel Pressure Relief Procedure . Disconnect the fuel feed hose from the fuel rail pipe. Refer to Quick Connect Fitting(s) Service (Metal Collar) . Install the J 37287 Fuel Line Shut-Off Adaptor between the fuel hoses and the fuel rail pipe. Open the valve on the fuel pipe shut-off adapter. Turn ON the ignition, with the engine OFF. Command the fuel pump ON with a scan tool. Bleed the air from the fuel pressure gage. Command the fuel pump ON and then OFF with a scan tool. Close the fuel feed pipe shut-off valve. Observe the fuel pressure gage for 1 minute. Does the fuel pressure remain constant? | | Go to Step 12 | Go to Step 11 |
| 8 | Is the fuel pressure more than the specified value? | 427 kPa (62 psi) | Go to Step 12 | Go to Step 9 |
| 9 | Inspect the fuel feed pipe for a restriction. Did you find and correct the condition? | | Go to Step 13 | Go to Step 10 |
| 10 | Inspect the harness connectors and ground circuits of the fuel pump for poor connections. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | | Go to Step 13 | Go to Step 12 |
| 11 | Turn OFF the ignition. Raise the fuel rail, with the fuel lines connected. Refer to Fuel Rail Assembly Replacement . Turn ON the ignition, with the engine OFF. Command the fuel pump ON with a scan tool. Locate and replace the leaking fuel injector. Refer to Fuel Injector Replacement . Did you complete the replacement? | | Go to Step 13 | |
| 12 | Replace the fuel pump. Refer to Fuel Sender Assembly Replacement . Did you complete the replacement? | | Go to Step 13 | |
| 13 | Operate the system in order to verify the repair. Did you correct the condition? | | System OK | Go to Step 3 |
| IMPORTANT |
|---|
| Inspect the fuel system for damage, or external leaks, before proceeding with this diagnostic. |
| IMPORTANT |
|---|
| Verify there is adequate fuel in the fuel tank before proceeding with this diagnostic. |
| CAUTION |
|---|
| Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel pressure gage. Place the towel in an approved container when the connection of the fuel pressure gage is complete. |
| IMPORTANT |
|---|
| It may be necessary to command the fuel pump ON several times in order to obtain the highest possible fuel pressure. DO NOT start the engine. |
| IMPORTANT |
|---|
| The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize and remain constant. |
The numbers below refer to the step numbers on the diagnostic table.
- 3: This step tests each fuel injector resistance within a specific temperature range. If any of the fuel injectors display a resistance outside of the specified value, replace the fuel injector.
- 4: This step determines if all of the fuel injectors are within 3 ohms of each other. If the highest resistance value is within 3 ohms of the lowest resistance value, then all of the fuel injector coil windings are OK.
- 5: This step determines which fuel injector is faulty. After subtracting the highest and lowest resistance values from the average value, replace the fuel injector that has the greatest resistance difference from the average.
| Step | Action | Values | Yes | No |
|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module (PCM) Connector End Views or Engine Controls Connector End Views |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 | Observe the engine coolant temperature (ECT) with a scan tool. Is the ECT value within the specified range? | 10-32°C (50-90°F) | Go to Step 3 | Go to Step 4 |
| 3 | Measure the resistance of each fuel injector with a DMM. Refer to Testing for Continuity in Wiring Systems. Do any of the fuel injectors display a resistance outside the specified range? | 11-14 ohms | Go to Step 6 | Go to Diagnostic Aids |
| 4 | Measure the resistance of each fuel injector with a DMM. Refer to Testing for Continuity in Wiring Systems. Record each fuel injector value. Subtract the lowest resistance value from the highest resistance value. Is the difference equal to or less than the specified value? | 3 ohms | Go to Diagnostic Aids | Go to Step 5 |
| 5 | Add all of the fuel injector resistance values, to obtain a total resistance value. Divide the total resistance value by the number of fuel injectors, to obtain an average resistance value. Subtract the lowest and the highest individual fuel injector resistance values, from the average resistance value. Replace the fuel injector that displays the greatest resistance difference, above or below the average. Refer to Fuel Injector Replacement . Did you complete the replacement? | | Go to Step 7 | |
| 6 | Replace the fuel injector or fuel injectors that are out of the specified range. Refer to Fuel Injector Replacement . Did you complete the replacement? | 11-14 ohms | Go to Step 7 | |
| 7 | Operate the system in order to verify the repair. Did you correct the condition? | | System OK | Go to Step 2 |
Scheme 594
Scheme 594: Fuel Injector Balance Test with Special Tool
| Callout | Component Name |
|---|
| 1 | First Fuel Pressure Gage Reading |
| 2 | Second Fuel Pressure Gage Reading |
| Cylinder | 1 | 2 | 3 | 4 |
|---|
| 1st Reading | 296 kPa (43 psi) | 296 kPa (43 psi) | 296 kPa (43 psi) | 296 kPa (43 psi) |
| 2nd Reading | 131 kPa (19 psi) | 117 kPa (17 psi) | 124 kPa (18 psi) | 145 kPa (21 psi) |
| Amount of Drop | 165 kPa (24 psi) | 179 kPa (26 psi) | 172 kPa (25 psi) | 151 kPa (22 psi) |
| Average Range: 156-176 kPa (22.5-25.5 psi) | Injector OK | Replace fuel injector - too much fuel pressure drop | Injector OK | Replace fuel injector - too little fuel pressure drop |
Fuel Injector Balance Test Example (Typical)
The numbers below refer to the step numbers on the diagnostic table.
- 3: The engine coolant temperature must be below the operating temperature in order to avoid irregular fuel pressure readings due to hot soak fuel boiling.
- 6: If the pressure drop value for each fuel injector is within 10 kPa (1.5 psi) of the average pressure drop value, the fuel injectors are flowing properly. Calculate the pressure drop value for each fuel injector by subtracting the second pressure reading from the first pressure reading. Refer to the illustration above.
| Step | Action | Values | Yes | No |
|---|
| 1 | Did you perform the Diagnostic System Check - Vehicle? | | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Did you perform the Fuel Injector Coil Test? | | Go to Step 3 | Go to Fuel Injector Coil Test |
| 3 | IMPORTANT: Do not perform this test if the engine coolant temperature is above 94°C (201°F). Observe the ECT parameter with a scan tool.Does the scan tool indicate that the ECT parameter is less than the specified value? | 94°C (201°F) | Go to Step 4 | |
| 4 | IMPORTANT: Verify there is adequate fuel in the fuel tank before proceeding with this diagnostic. Turn OFF the ignition. Install the fuel pressure gage. Refer to Fuel Pressure Gage Installation and Removal . Turn ON the ignition, with the engine OFF. Command the fuel pump ON with a scan tool. IMPORTANT: It may be necessary to command the fuel pump ON a few times, in order to obtain the highest possible fuel pressure. Do not start the engine. Observe the fuel pressure gage, with the fuel pump commanded ON. Is the fuel pressure within the specified range? | 384-425 kPa (55-62 psi) | Go to Step 5 | Go to Fuel System Diagnosis |
| 5 | IMPORTANT: The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize and remain constant. Monitor the fuel pressure gage for one minute.Does the fuel pressure drop more than the specified value? | 34 kPa (5 psi) | Go to Fuel System Diagnosis | Go to Step 6 |
| 6 | Connect the J 39021 Fuel Injector Coil and Balance Tester and the J 39021-380 Fuel Injector Test Harness to a fuel injector. Set the amperage supply selector switch on the fuel injector tester to the Balance Test 0.5-2.5 amp position. Command the fuel pump ON and then OFF with a scan tool. Record the fuel pressure indicated by the fuel pressure gage after the fuel pressure stabilizes. This is the first pressure reading. IMPORTANT: Record the fuel pressure value immediately after the fuel injector stops pulsing. The fuel pressure may rise after the fuel injector stops pulsing. Do not record the higher fuel pressure value. Energize the fuel injector by depressing the Push to Start Test button on the fuel injector tester. Record the fuel pressure indicated by the fuel pressure gage. This is the second fuel pressure reading. Repeat steps 1-6 for each fuel injector. Subtract the second pressure reading from the first pressure reading for one fuel injector. The result is the pressure drop value. Obtain a pressure drop value for each fuel injector. Add all of the individual pressure drop values. This is the total pressure drop. Divide the total pressure drop by the number of fuel injectors. This is the average pressure drop. Does any fuel injector have a pressure drop value that is more than the average pressure drop or less than the average pressure drop by the specified value? | 20 kPa (3 psi) | Go to Step 7 | Go to Symptoms - Engine Controls |
| 7 | Perform the Fuel Injector Cleaning Procedure . Did you complete the procedure? | | Go to Step 8 | |
| 8 | Operate the vehicle in order to verify the repair. Does a driveability condition still exist? | | Go to Symptoms - Engine Controls | System OK |
| IMPORTANT |
|---|
| Do not perform this test if the engine coolant temperature is above 94°C (201°F). |
| IMPORTANT |
|---|
| Verify there is adequate fuel in the fuel tank before proceeding with this diagnostic. |
| IMPORTANT |
|---|
| It may be necessary to command the fuel pump ON a few times, in order to obtain the highest possible fuel pressure. Do not start the engine. |
| IMPORTANT |
|---|
| The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize and remain constant. |
| IMPORTANT |
|---|
| Record the fuel pressure value immediately after the fuel injector stops pulsing. The fuel pressure may rise after the fuel injector stops pulsing. Do not record the higher fuel pressure value. |
Fuel Injector Balance Test with Special Tool
The numbers below refer to the step numbers on the diagnostic table.
- 3: The engine coolant temperature must be below the operating temperature in order to avoid irregular fuel pressure readings due to hot soak fuel boiling.
- 4: The fuel pressure should be within the specified range.
- 5: The fuel pressure should reach a steady value.
- 6: If the pressure drop value for each fuel injector is within 10 kPa (1.5 psi) of the average pressure drop value, the fuel injectors are flowing properly. Calculate the pressure drop value for each fuel injector by subtracting the second pressure reading from the first pressure reading.
| Step | Action | Values | Yes | No |
|---|
| 1 | Did you perform the Diagnostic System Check - Vehicle? | | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Did you perform the Fuel Injector Coil Test? | | Go to Step 3 | Go to Fuel Injector Coil Test |
| 3 | IMPORTANT: Do not perform this test if the engine coolant temperature is above 94°C (201°F). Observe the ECT parameter with a scan tool.Does the scan tool indicate that the ECT parameter is less than the specified value? | 94°C (201°F) | Go to Step 4 | |
| 4 | IMPORTANT: Verify there is adequate fuel in the fuel tank before proceeding with this diagnostic. Turn OFF the ignition. Turn OFF all accessories. Install the fuel pressure gage. Refer to Fuel Pressure Gage Installation and Removal . Turn ON the ignition, with the engine OFF. Command the fuel pump ON with a scan tool. IMPORTANT: It may be necessary to command the fuel pump ON a few times in order to obtain the highest possible fuel pressure. Do not start the engine. Observe the fuel pressure gage, with the fuel pump commanded ON. Is the fuel pressure within the specified value? | 384-425 kPa (55-62 psi) | Go to Step 5 | Go to Fuel System Diagnosis |
| 5 | IMPORTANT: The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize and remain constant. Monitor the fuel pressure gage for 1 minute.Does the fuel pressure drop more than the specified value? | 34 kPa (5 psi) | Go to Fuel System Diagnosis | Go to Step 6 |
| 6 | With a scan tool, select the Fuel Injector Balance Test function, within the Special Functions menu. Select an injector to be tested. Press Enter. This will prime the fuel system. Record the fuel pressure indicated by the fuel pressure gage after the fuel pressure stabilizes. This is the 1st pressure reading. IMPORTANT: Record the fuel pressure value immediately after the fuel injector stops pulsing. The fuel pressure may rise after the fuel injector stops pulsing. Do not record the higher fuel pressure value. Energize the fuel injector by depressing the Pulse Injector button on the scan tool. This will energize the injector and decrease the fuel pressure. Record the fuel pressure indicated by the fuel pressure gage after the fuel injector has stopped pulsing. This is the 2nd pressure reading. Press Enter again to bring you back to the Select Injector screen. Repeat for each fuel injector. Subtract the 2nd pressure reading from the 1st pressure reading for one fuel injector. The result is the pressure drop value. Obtain a pressure drop value for each fuel injector. Add all of the individual pressure drop values. This is the total pressure drop. Divide the total pressure drop by the number of fuel injectors. This is the average pressure drop. Does any fuel injector have a pressure drop value that is either higher than the average pressure drop or lower than the average pressure drop by the specified value? | 20 kPa (3 psi) | Go to Step 7 | Go to Symptoms - Engine Controls |
| 7 | Perform the Fuel Injector Cleaning Procedure . Did you complete the procedure? | | Go to Step 8 | |
| 8 | Operate the vehicle in order to verify the repair. Does a driveability condition still exist? | | Go to Symptoms - Engine Controls | System OK |
| IMPORTANT |
|---|
| Do not perform this test if the engine coolant temperature is above 94°C (201°F). |
| IMPORTANT |
|---|
| Verify there is adequate fuel in the fuel tank before proceeding with this diagnostic. |
| IMPORTANT |
|---|
| It may be necessary to command the fuel pump ON a few times in order to obtain the highest possible fuel pressure. Do not start the engine. |
| IMPORTANT |
|---|
| The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize and remain constant. |
| IMPORTANT |
|---|
| Record the fuel pressure value immediately after the fuel injector stops pulsing. The fuel pressure may rise after the fuel injector stops pulsing. Do not record the higher fuel pressure value. |
Fuel Injector Balance Test with Tech 2
The fuel tank leak test is used to locate any fuel or fuel vapor escaping the fuel tank area. Fuel vapors escaping above the fuel level will be detected when the evaporative emission (EVAP) diagnostics complete one test cycle. The malfunction indicator lamp (MIL) will illuminate after the EVAP diagnostics have failed two test cycles.
The numbers below refer to the step numbers on the diagnostic table.
- 4: This step tests for fuel leaks below the fuel tank fuel level.
- 5: This step tests for fuel vapors escaping above the fuel level in the fuel tank.
| Step | Action | Yes | No |
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| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | CAUTION: Gasoline or gasoline vapors are highly flammable. A fire could occur if an ignition source is present. Never drain or store gasoline or diesel fuel in an open container, due to the possibility of fire or explosion. Have a dry chemical (Class B) fire extinguisher nearby. Raise the vehicle. Refer to Lifting and Jacking the Vehicle . Inspect the fuel tank and fuel pipes for damage or external leaks. Did you find fuel leaking from the fuel tank? | Go to Step 6 | Go to Step 3 |
| 3 | Turn ON the ignition, with the engine OFF. Command the fuel pump relay ON with a scan tool. Inspect for fuel leaking from the fuel pipes. Did fuel leak from the fuel pipes? | Go to Step 7 | Go to Step 4 |
| 4 | Turn OFF the ignition. Install the J 41413-200 Evaporative Emissions System Tester (EEST) and the J 41415-40 Fuel Tank Cap Adaptor or the GE-41415-50 Interrupted Thread Fuel Tank Cap Adapter. IMPORTANT: If the floating indicator registers any flow after stabilizing, a leak is evident. Test for a fuel tank leak referring to the J 41413-210 Operation Manual. Raise the vehicle. Refer to Lifting and Jacking the Vehicle . Inspect for a fuel leak while the system is under pressure. Did fuel leak from the fuel tank? | Go to Step 6 | Go to Step 5 |
| 5 | Using the J 41413-200 and the J 41413-210 Operation Manual, introduce smoke into the evaporative emission (EVAP) system. IMPORTANT: It may be necessary to partially lower the fuel tank. Refer to Fuel Tank Replacement (Pickup) or Fuel Tank Replacement (Cab/Chassis - Front) or Fuel Tank Replacement (Cab/Chassis - Rear) . Inspect for leaks in any of the following locations: The fuel tank, fill limiter vent valve, the pressure relief valve, and the grade vent valves - Refer to Fuel Tank Replacement (Pickup) or Fuel Tank Replacement (Cab/Chassis - Front) or Fuel Tank Replacement (Cab/Chassis - Rear) . The fuel sender housing and the fuel sender seal - Refer to Fuel Sender Assembly Replacement . The fuel tank pressure (FTP) sensor seal - Refer to Fuel Tank Pressure Sensor Replacement . The EVAP vapor pipes - Refer to Evaporative Emission (EVAP) Hoses/Pipes Replacement - Engine . The fuel fill pipe and hose - Refer to Filler Tube Replacement (Pickup) or Filler Tube Replacement (Cab/Chassis - Front) or Filler Tube Replacement (Cab/Chassis - Rear) . Did you find and correct the condition? | Go to Step 8 | Go to Diagnostic Aids |
| 6 | Replace the fuel tank. Refer to Fuel Tank Replacement (Pickup) or Fuel Tank Replacement (Cab/Chassis - Front) or Fuel Tank Replacement (Cab/Chassis - Rear) . Did you complete the repair? | Go to Step 8 | |
| 7 | Replace the leaking fuel pipe. Refer to Fuel Hose/Pipes Assembly Replacement . Did you complete the replacement? | Go to Step 8 | |
| 8 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
| CAUTION |
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| Gasoline or gasoline vapors are highly flammable. A fire could occur if an ignition source is present. Never drain or store gasoline or diesel fuel in an open container, due to the possibility of fire or explosion. Have a dry chemical (Class B) fire extinguisher nearby. |
| IMPORTANT |
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| If the floating indicator registers any flow after stabilizing, a leak is evident. |
| IMPORTANT |
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| It may be necessary to partially lower the fuel tank. Refer to Fuel Tank Replacement (Pickup) or Fuel Tank Replacement (Cab/Chassis - Front) or Fuel Tank Replacement (Cab/Chassis - Rear) . |
Water contamination in the fuel system may cause driveability conditions such as hesitation, stalling, no start, or misfires in one or more cylinders. Water may collect near a single fuel injector at the lowest point in the fuel injection system, and cause a misfire in that cylinder. If the fuel system is contaminated with water, inspect the fuel system components for rust or deterioration.
Ethanol concentrations of greater than 10 percent can cause driveability conditions and fuel system deterioration. Fuel with more than 10 percent ethanol could result in driveability conditions such as hesitation, lack of power, stalling, or no start. Excessive concentrations of ethanol used in vehicles not designed for it may cause fuel system corrosion, deterioration of rubber components, and fuel filter restriction.
The numbers below refer to the step numbers on the diagnostic table.
- 5: Monitoring the misfire current counters determines if a fault is present.
- 12: A good indication that the fuse is open is all off the misfire current counters are incrementing on one side of the engine. Inspect the ignition positive voltage circuit for a grounded circuit. If the fuse is open and the ignition coil circuits are OK, inspect the injector circuits for being grounded.
| Step | Action | Value(s) | Yes | No |
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| Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module (PCM) Connector End Views or Engine Controls Connector End Views |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Crank the engine. Observe the engine speed parameter with a scan tool. Does the scan tool display engine RPM? | | Go to Step 3 | Go to Step 16 |
| 3 | Is DTC P0335, P0336, or P0351-P0358 also set? | | Go to Diagnostic Trouble Code (DTC) List - Vehicle | Go to Step 4 |
| 4 | Attempt to start the engine. Does the engine start and run? | | Go to Step 5 | Go to Step 9 |
| 5 | Idle the engine. Observe the misfire current counters on the scan tool. Does the scan tool display any misfire current counters incrementing? | | Go to Step 6 | Go to Diagnostic Aids |
| 6 | Do the misfire current counters increment for most cylinders on one bank of the engine? | | Go to Step 12 | Go to Step 7 |
| 7 | Inspect the spark plug wire for open circuits, cracks, or improper seating of terminals at the spark plug or coil before proceeding with test. Refer to Spark Plug Wire Inspection . Inspect for spark at the plug with the J 26792 Spark Tester or equivalent while cranking. A few sparks, then nothing is considered no spark. Is adequate spark present? | | Go to Step 33 | Go to Step 8 |
| 8 | Measure the spark plug wire resistance. Refer to Spark Plug Wire Inspection . Is the resistance more than the specified value? | 1,000 ohms/ft | Go to Step 32 | Go to Step 9 |
| 9 | Turn OFF the ignition. Disconnect the ignition coil that corresponds to the Misfire Current counter that was incrementing. Turn ON the ignition, with the engine OFF. Probe the ignition 1 voltage circuit of the ignition coil with a test lamp connected to a good ground. Refer to Probing Electrical Connectors . Does the test lamp illuminate? | | Go to Step 10 | Go to Step 13 |
| 10 | Probe the ignition 1 voltage circuit at the ignition coil with a test lamp connected to the ground circuit of the ignition coil. Refer to Probing Electrical Connectors . Does the test lamp illuminate? | | Go to Step 11 | Go to Step 14 |
| 11 | Probe the ignition 1 voltage circuit at the ignition coil with a test lamp connected to the low reference circuit of the ignition coil. Refer to Probing Electrical Connectors . Does the test lamp illuminate? | | Go to Step 20 | Go to Step 15 |
| 12 | Inspect for an open INJ 1 or INJ 2 fuse. Is the fuse open? | | Go to Step 29 | Go to Step 23 |
| 13 | Disconnect the main ignition coil 8-way connector. Probe the ignition 1 voltage circuit at the ignition coil main 8-way connector using the test lamp connected to battery ground. Refer to Probing Electrical Connectors . Does the test lamp illuminate? | | Go to Step 24 | Go to Step 23 |
| 14 | Disconnect the main ignition coil 8-way connector. Probe the ignition 1 voltage circuit on the harness side with a test lamp connected to the ground circuit of the ignition coil. Refer to Probing Electrical Connectors . Does the test lamp illuminate? | | Go to Step 18 | Go to Step 26 |
| 15 | Disconnect the main ignition coil 8-way connector. Probe the ignition 1 voltage circuit on the harness side with a test lamp connected to the low reference circuit of the ignition coil. Refer to Probing Electrical Connectors . Does the test lamp illuminate? | | Go to Step 19 | Go to Step 28 |
| 16 | Turn ON the ignition, with the engine OFF. Disconnect the crankshaft position (CKP) sensor. Measure the voltage from the CKP sensor 12-volt reference circuit and a good ground with the DMM. Compare the measured voltage with the system voltage. Is the difference in the voltage more than the specified value? | 0.5 V | Go to Step 17 | Go to Step 21 |
| 17 | Test for a short to ground in the CKP 12-volt reference circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | | Go to Step 35 | Go to Step 22 |
| 18 | Test for an intermittent and for a poor connection at the ignition coil 8-way connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | | Go to Step 35 | Go to Step 25 |
| 19 | Test for an intermittent and for a poor connection at the ignition coil 8-way connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | | Go to Step 35 | Go to Step 27 |
| 20 | Test for an intermittent and for a poor connection at the ignition coil. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | | Go to Step 35 | Go to Step 31 |
| 21 | Test for an intermittent and for a poor connection at the CKP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | | Go to Step 35 | Go to Step 30 |
| 22 | Test for an intermittent and for a poor connection at the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | | Go to Step 35 | Go to Step 34 |
| 23 | Repair the open or high resistance in the ignition 1 voltage circuit between the fuse block and the splice. Refer to Wiring Repairs . Did you complete the repair? | | Go to Step 35 | |
| 24 | Repair the open or high resistance in the ignition 1 voltage circuit between the splice and the ignition coil connector. Refer to Wiring Repairs . Did you complete the repair? | | Go to Step 35 | |
| 25 | Repair the open in the ground circuit between the main 8-way connector and the ignition coil. Refer to Wiring Repairs . Did you complete the repair? | | Go to Step 35 | |
| 26 | Repair the open in the ground circuit. Refer to Wiring Repairs . Did you complete the repair? | | Go to Step 35 | |
| 27 | Repair the open in the low reference circuit between the main 8-way connector and the ignition coil. Refer to Wiring Repairs . Did you complete the repair? | | Go to Step 35 | |
| 28 | Repair the open in the low reference circuit between the PCM and the splice. Refer to Wiring Repairs . Did you complete the repair? | | Go to Step 35 | |
| 29 | Repair the ignition 1 voltage for a short to ground. Refer to Wiring Repairs . Replace the fuse. Did you complete the repair? | | Go to Step 35 | |
| 30 | Replace the CKP sensor. Refer to Crankshaft Position (CKP) Sensor Replacement . Did you complete the replacement? | | Go to Step 35 | |
| 31 | Replace the ignition coil. Refer to Ignition Coil(s) Replacement . Did you complete the replacement? | | Go to Step 35 | |
| 32 | Replace the spark plug wire. Refer to Spark Plug Wire Replacement . Did you complete the replacement? | | Go to Step 35 | |
| 33 | Replace the spark plug. Refer to Spark Plug Replacement . Did you complete the replacement? | | Go to Step 35 | |
| 34 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | | Go to Step 35 | |
| 35 | Attempt to start the engine. Does the engine start and continue to run? | | Go to Step 36 | Go to Step 2 |
| 36 | Clear the DTCs with a scan tool. Turn OFF the engine for 30 seconds. Start the engine. Allow the engine to reach operating temperature. Are there any DTCs that have not been diagnosed? | | System OK | Go to Diagnostic Trouble Code (DTC) List - Vehicle |
Electronic Ignition (EI) System Diagnosis
Several states require that a vehicle pass on-board diagnostic (OBD) system tests and the inspection/maintenance (I/M) emission inspection in order to renew license plates. This is accomplished by viewing the I/M System Status display on a scan tool. Using a scan tool, the technician can observe the I/M System Status in order to verify that the vehicle meets the criteria that comply with the local area requirements.
The purpose of the Inspection/Maintenance (I/M) complete system set procedure is to satisfy the enable criteria necessary to execute all of the I/M readiness diagnostics and complete the drive cycles for those particular diagnostics. When all I/M monitored diagnostic tests are completed, the I/M System Status indicators are set to YES. Perform the I/M Complete System Set Procedure if any I/M System Status indicators are set to NO.
