P0302-CYLINDER 2 MISFIRE

P0302-CYLINDER 2 MISFIREFor a complete wiring diagram Refer to Section 8W.When Monitored:Any time the engine is running, and the adaptive numerator has been successfully updated.Set Condition:The threshold to set the fault is application specific; it is tied to the level of misfire that will cause emissions to increase to 1.5 times the standard or in some cases 1%. It is always a two trip fault above the calibrated RPM. It takes 1 soft fail to set a malfunction and two trips to set the MIL. Three good trips to turn off the MIL.

Possible Causes(F342) ASD RELAY OUTPUT CIRCUIT(K12) INJECTOR 2 CONTROL CIRCUIT(K17) COIL CONTROL 2 CIRCUITIGNITION WIRESPARK PLUGIGNITION COILFUEL PUMP INLET STRAINER PLUGGEDRESTRICTED FUEL SUPPLY LINEFUEL PUMP MODULEFUEL PRESSURE LEAK DOWNFUEL INJECTORENGINE MECHANICALPCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).Diagnostic Test1. CYLINDER MISFIRE CONDITION ACTIVEEngine running.Observe the WHICH CYLINDER IS MISFIRING screen for at least one minute with the scan tool.Is there a misfire present?YesGo To 2NoRefer to the INTERMITTENT CONDITION Diagnostic Procedure.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) 2. VISUAL INSPECTIONAnything that affects the speed of the crankshaft can cause a misfire DTC.When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit.- Visually inspect the engine for any of the following conditions.- Worn serpentine belt- Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump.- Misalignment of the Water pump, P/S Pump and A/C Compressor pulleys- Corroded PCM power and ground circuits.- Improper CKP, CMP, MAP, and TP Sensor mounting- Poor connector/terminal to component connection. i.e., CKP sensor, Fuel Injector, Ignition coil, etc.- Vacuum leaks- Restricted Air Induction system or Exhaust system.- Internal engine component failures.Were any of the above conditions present?YesRepair as necessary.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 33. (F342) ASD RELAY OUTPUT CIRCUIT

Turn the ignition off.Disconnect the Ignition Coil harness connector.Disconnect the Fuel Injector No.2 harness connector.Ignition on, engine not running.With the scan tool, actuate the ASD Relay.Using a 12-volt test light connected to ground, probe the (F342) ASD Relay Output circuit in the Ignition Coil harness connector and Fuel Injector harness connector while the ASD Relay is actuating.Does the test light illuminate brightly?YesGo To 4NoRepair the excessive resistance or short to ground in the (F342) ASD Relay Output circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) 4. IGNITION SYSTEM OPERATIONTurn the ignition off.Connect the Ignition harness connector.Remove the Ignition wire from the Cylinder 2 Spark Plug.Leave the Fuel Injector harness connector of the cylinder being tested disconnected.Install a spark tester on the Ignition wire.While cranking the engine observe the spark coming from the spark tester.A crisp blue spark that is able to jump the gap of the spark tester should be generated.Is good spark present?YesGo To 5NoGo To 14Connect the Fuel Injector harness connector before continuing.5. SPARK PLUGTurn the ignition off.Remove the Spark Plug.Inspect the Spark Plug for the following conditions.- Cracks- Carbon Tracking- Foreign Material- Gap size out of specifications- Loose or broken electrodeLightly tap the bottom of the spark plug on a solid surface. The electrode in the spark plug should not move.Were any of the above conditions present?YesReplace the Spark Plug.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) NoGo To 66. FUEL PRESSURE CHECKThe 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 personal injury or death.Install a fuel pressure gauge to the fuel rail.Start the engine and observe the fuel pressure reading.Fuel pressure specification is 407 kPa +/- 34 kPa (59 psi +/- 5 psi).Choose a conclusion that best matches your fuel pressure reading.Within SpecificationGo To 7Below SpecificationGo To 12Above SpecificationReplace the fuel filter/pressure regulator.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) 7. FUEL PRESSURE LEAK DOWNBefore continuing visually and physically inspect the fuel delivery system for external leaks or damage. Repair / replace as necessary.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 personal injury or death.Turn the ignition off.Install special tool #6539 (5/16") or #6631 (3/8") fuel line adapter.Install the fuel pressure gauge.Start the engine and allow the fuel system to reach maximum pressure.Turn the ignition off.Fuel specification is 407 kPa +/- 34 kPa (59 psi +/- 5 psi).Using special tool #C4390, Hose Clamp Pliers, pinch the rubber fuel line between the fuel pressure gauge and the engine.Monitor the fuel pressure gauge for a minimum of 5 minutes.The pressure should not fall below 241 kPa (35 psi)Does the pressure fall below the listed specification?YesReplace the leaking Fuel Injector(s).Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) NoGo To 88. FUEL INJECTOR OPERATIONThe 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 personal injury or death.After each Fuel Injector actuation, start the engine to clean the cylinder of fuel. Failure to do so could cause engine damage.Remove special tool #C4390.Start the engine and allow the fuel pressure to reach maximum pressure.Ignition on, engine not running.Using scan tool, actuate the No.2 Fuel Injector.Monitor the fuel pressure gauge.Does the fuel pressure gauge indicate a drop in fuel pressure?YesGo To 9NoGo To 10Turn the ignition off, remove the Fuel Pressure gauge, and connect the fuel lines before continuing.9. ENGINE MECHANICALCheck for any of the following conditions/mechanical problems.ENGINE VACUUM - must be at least 13 inches in neutralENGINE VALVE TIMING - must be within specificationsENGINE COMPRESSION - must be within specificationsENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks.ENGINE PCV SYSTEM - must flow freelyTORQUE CONVERTER STALL SPEED - must be within specificationsPOWER BRAKE BOOSTER - no internal vacuum leaksFUEL - must be free of contaminationCAM LOBES - must not be worn excessivelyCYLINDER LEAKAGE TEST - must be within specificationsVALVE SPRINGS - cannot be weak or brokenAre there any engine mechanical problems?YesRepair as necessary.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) NoGo To 1710. FUEL INJECTORTurn the ignition off.Disconnect the No.2 Fuel Injector harness connector.Ignition on, engine not running.When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit.With the scan tool, erase DTCs.Install an Injector Noid light.With the scan tool, actuate the Fuel Injector.Does the Noid light blink/flicker during the actuation?YesReplace the Fuel Injector.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) NoGo To 1111. (K12) INJECTOR 2 CONTROL CIRCUIT

Turn the ignition off.Disconnect the C2 PCM harness connector.Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.Check the (K12) Injector 2 Control circuit for an open, short to ground, and short to voltage.Was a problem found with the (K12) Injector 2 Control circuit?YesRepair the excessive resistance or short in the (K12) Injector 2 Control circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) NoGo To 1712. FUEL SUPPLY LINE RESTRICTEDThe 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 personal injury or death.Turn the ignition off.Raise vehicle on hoist, and disconnect the fuel pressure line at the fuel pump module.Install special tool #6539 (5/16") #6631(3/8") fuel line adapter and the fuel pressure gauge between the fuel supply line and the fuel pump module.Ignition on, engine not running.With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge.Fuel pressure specification is 407 kPa +/- 34 kPa (59 psi +/- 5 psi).Is the fuel pressure within specification?YesRepair or replace fuel supply line as necessary.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 1313. FUEL PUMP INLET STRAINERThe 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 personal injury or death.Turn the ignition off.Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer.Is the Fuel Inlet Strainer plugged?YesReplace the Fuel Pump Inlet Strainer.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoBefore continuing, check the Fuel Pump Module harness connector terminals for corrosion, damage, or terminal push out. Make sure the ground circuit is functional. Repair as necessary. Replace the Fuel Pump Module.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) 14. IGNITION WIREDisconnect the Cylinder 2 Ignition wire from the Ignition Coil and Spark Plug.Inspect both ends of the Ignition Wire and the terminals on the Spark Plug and Ignition Coil for excessive corrosion. Clean/Repair as necessary.Measure the resistance of the Cylinder 2 Ignition wire.Is the resistance above 22.8K ohms?YesReplace the Ignition Wire.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) NoGo To 1515. IGNITION COIL

When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.Disconnect the Ignition Coil harness connector.Using a 12-volt test light connected to 12-volts, probe the (K17) Coil Control 2 circuit.Crank the engine for 5 seconds.Does the test light brightly blink/flicker while the engine is cranking?YesReplace the Ignition Coil.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 1616. (K17) COIL CONTROL 2 CIRCUIT