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Home >> Mazda >> 2006 >> B3000 Base, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Symptom Troubleshooting - (3 Of 5) >> DTC Application Chart - Powertrain Control Module (Pcm) >> Misfire Detection Monitor
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Misfire Detection Monitor

DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0316 DETECTION CONDITION & POSSIBLE CAUSES

DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0316 MISFIRE DETECTION MONITOR
DETECTION CONDITION 
  • P0300 indicates multiple cylinders are misfiring or the powertrain control module (PCM) cannot identify which cylinder is misfiring.
  • P0301 through P0306 indicates random misfire detected or cylinder 1, 2, 3, 4, 5, or 6 misfire detected.
  • P0316 code is set in addition to any type B misfire DTC which occurs in the first 1, 000 revolution test interval following engine start.
POSSIBLE CAUSE 
  • Ignition system
  • Fuel injectors
  • Fuel pressure
  • Evaporative emission (EVAP) system
  • Base engine
  • Low fuel or running out of fuel
  • Fuel quality
  • Camshaft position (CMP) sensor
  • Crankshaft position (CKP) sensor
  • PCM
HINT 
G04306931Courtesy of MAZDA MOTORS CORP.
G04306932Courtesy of MAZDA MOTORS CORP.
G04306933Courtesy of MAZDA MOTORS CORP.
G04306934Courtesy of MAZDA MOTORS CORP.
DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0316 DIAGNOSTIC PROCEDURE

DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0316 MISFIRE DETECTION MONITOR
STEP INSPECTION ACTION
1
  • Was the PCM quick test performed?
 Yes If any other DTCs are present, Go to appropriate pinpoint test.
For DTC P0300 only, Go to step 16.
Otherwise, Go to next step.
No Perform PCM quick test. See PCM QUICK TEST  .
2 CHECK FUEL PRESSURE
WARNING:
  • The fuel system will remain pressurized when the engine is not running. To prevent injury or fire, use caution when working on the fuel system.
  • Install fuel pressure gauge.
  • Key on, engine running (KOER).
  • Note fuel pressure.
  • Increase engine speed to 2, 500 rpm and maintain for 1 minute. Note and compare fuel pressure.
  • Key OFF.
  • Was fuel pressure between 207-448 kPa (30-65 psi) for 3.0L/4.0L or 240-380kPa (35-55 psi) for 2.3L and did it remain at specification within 35 kPa (5 psi) for 60 seconds? 
 Yes Go to next step.
No See GENERAL PINPOINT TEST 5: FUEL DELIVERY SYSTEM .
3 CHECK INJECTOR DRIVER PIDS INJ1F THROUGH INJ6F
  • Key on, engine off (KOEO).
  • Access appropriate PID(s) for the suspect fuel injector.
  • Is the PID status Yes? 
 Yes Go to next step.
No Go to step 7.
4 CHECK RESISTANCE OF FUEL INJECTOR(S) AND HARNESS
  • Disconnect PCM.
  • Install breakout box, leave PCM disconnected.
  • Measure resistance of INJ circuit between PCM test pin 71 or 97 and the suspect fuel injector PCM test pin.
  • Is the resistance between 11.0 and 18.0 ohms for 4.0L or between 8.5 and 15.5 ohms for 3.0L or 11.0-13.0 ohms for 2.3L? 
 Yes Replace PCM.
See POWERTRAIN CONTROL MODULE (PCM) REMOVAL / INSTALLATION .
Go to step 17.
No Go to next step.
5 CHECK RESISTANCE OF FUEL INJECTOR HARNESS
  • Disconnect harness connector at suspected fuel injector.
  • Measure resistance of VPWR circuit between PCM test pin 71 or 97 and the fuel injector harness connector.
  • Measure resistance of INJ circuit between appropriate PCM test pin and the suspect fuel injector test pin.
    • INJ1F: test pin 75
    • INJ2F: test pin 101
    • INJ3F: test pin 74
    • INJ4F: test pin 100
    • INJ5F: test pin 73
    • INJ6F: test pin 99
  • Is each resistance less than 5.0 ohms? 
 Yes Go to next step.
No Repair open circuit.
Go to step 17.
6 CHECK FUEL INJECTOR HARNESS CIRCUIT FOR SHORT TO POWER OR GROUND
  • Measure resistance between PCM test pin 71 (VPWR) and suspect fuel injector SIG circuit PCM test pin(s).
  • Measure resistance between PCM test pin 103 (PWR GND) and suspect fuel injector SIG circuit PCM test pin(s).
  • Is each resistance greater 10K ohms? 
 Yes Go to next step.
No Repair short circuit.
Go to step 17.
7 INSPECT FUEL INJECTOR OPERATION
  • Remove fuel injector from suspected cylinder.
  • Swap suspected fuel injector with a fuel injector from another cylinder.
  • Key ON, Engine Running (KOER).
  • Does misfire DTC move to cylinder with suspected Injector? 
 Yes Replace fuel injector.
Go to step 17.
No Go to next step.
8 CHECK VACUUM SYSTEM
NOTE:
  • Some vacuum leaks can be heard.
  • Inspect all vacuum lines for damage, such as pinched lines, cracks, proper routing and assembly.
  • Is the vehicle vacuum system OK? 
 Yes Go to next step.
No Repair the vacuum system.
Go to step 17.
9 CHECK DAMPER AND PULLEY ASSEMBLY
CAUTION:
  • Remove the front cover if necessary to observe the crankshaft pulley.
  • Observe the crankshaft pulley for wobble.
  • Examine the pulse ring fastened to the harmonic damper.
  • Does the crankshaft pulley wobble or is the pulse ring loose or damaged? 
 Yes Disconnect battery for 5 minutes to allow PCM to learn new data, due to the old pulse ring. Replace the pulley or damper assembly.
Go to step 17.
No Go to next step.
10 CHECK EVAPORATIVE EMISSION SYSTEM
NOTE:
  • The misfire monitor can be influenced by the evaporative emission (EVAP) system. The next five test steps will diagnose the EVAP system.
  • Check the evaporative emissions canister for fuel saturation.
  • Is there an excess amount of liquid fuel present in the evaporative emissions canister? 
 Yes Replace evaporative emissions canister.
See EVAPORATIVE EMISSIONS CANISTER REMOVAL / INSTALLATION .
Go to step 17.
No Check fuel tank vent system.
Go to next step.
11 PRESSURE TEST EVAPORATIVE EMISSION SYSTEM Yes Go to next step.
No Repair as necessary.
Go to step 17.
12 CHECK VACUUM IN EVAPORATIVE EMISSION SYSTEM Yes Replace damaged vacuum hoses or remove blockage/restrictions.
Go to step 17.
No Go to next step.
13 CHECK FOR EVAPORATIVE EMISSION PURGE VALVE HOUSING LEAKS
  • Verify that the EVAP purge valve is electrically connected.
  • Install a hand vacuum pump to the fuel vapor port from the EVAP canister on the EVAP canister purge vacuum valve at the line.
  • Apply 53 kPa (16 in-Hg) of vacuum with the vacuum pump.
  • Does the EVAP canister purge valve hold vacuum at room temperature? 
 Yes Go to next step.
No Remove vacuum pump.
Replace EVAP canister purge solenoid.
See CANISTER PURGE VALVE REMOVAL / INSTALLATION . Go to step 17.
14 CHECK FOR FILTER CONTAMINATION OR DAMAGE ON EVAPORATIVE EMISSION PURGE VALVE
  • Remove the vacuum line from the input vacuum port to the intake manifold on the EVAP canister purge valve (the control vacuum solenoid part of the valve).
  • Install a hand held vacuum pump to the open input vacuum port on the EVAP canister purge solenoid.
  • Apply 48-52 kPa (14-15 in-Hg) of vacuum to the EVAP canister purge solenoid.
  • Does the EVAP purge valve hold vacuum or is the valve very slow to release vacuum to atmosphere? 
 Yes Service EVAP canister purge solenoid filter. If unable to clean filter or remove blockage, replace the EVAP canister purge solenoid.
See CANISTER PURGE VALVE REMOVAL / INSTALLATION .
Go to step 17.
No Remove vacuum pump.
Connect all components.
Go to next step.
15 CHECK FOR BASE ENGINE CONCERNS
NOTE:
  • This step will determine if there are any base engine concerns that may have caused the misfire DTC or drive concern.
  • Perform the following tests in order to evaluate base engine integrity.
    • Perform engine compression test
    • Perform valve train analysis
    • Check PCV system
    • Check possible leakage points
  • See ENGINE COMPONENT TEST for all of the above.
  • Is any service required? 
 Yes Service as necessary.
Go to step 17.
No The fault that caused the misfire DTC is an intermittent.
See GENERAL PINPOINT TEST 4: INTERMITTENT .
16 CHECK CMP SENSOR OUTPUT
  • Disconnect PCM.
  • Install breakout box, PCM connected.
  • Set multimeter on AC scale (monitor less than 5.0 volts).
  • Measure voltage between PCM test pin 85 (CMP) and PCM test pins 51, 103 (PWR GND) while running the engine at varying rpm.
  • Does AC voltage vary greater than 0.1 V? 
 Yes Verify CMP sensor is installed correctly.
See CAMSHAFT POSITION (CMP) SENSOR REMOVAL / INSTALLATION - 4.0L .
See CAMSHAFT POSITION (CMP) SENSOR REMOVAL / INSTALLATION - 3.0L .
See CAMSHAFT POSITION (CMP) SENSOR REMOVAL / INSTALLATION - 2.3L .
If CMP is installed correctly, replace PCM.
See POWERTRAIN CONTROL MODULE (PCM) REMOVAL / INSTALLATION .
Go to next step.
No Replace CMP sensor.
See CAMSHAFT POSITION (CMP) SENSOR REMOVAL / INSTALLATION - 4.0L .
See CAMSHAFT POSITION (CMP) SENSOR REMOVAL / INSTALLATION - 3.0L .
See CAMSHAFT POSITION (CMP) SENSOR REMOVAL / INSTALLATION - 2.3L .
Go to next step.
17 DRIVE CYCLE
  • Connect all disconnected connectors.
  • Clear DTCs from PCM memory using WDS or equivalent tester.
  • Perform misfire monitor drive cycle. See DRIVE CYCLES .
  • Retrieve pending code.
  • Is same DTC present? 
 Yes Replace PCM.
See POWERTRAIN CONTROL MODULE (PCM) REMOVAL / INSTALLATION .
Go to next step.
No Go to next step.
18 VERIFY TROUBLESHOOTING OF DTCs COMPLETED
  • Perform PCM quick test.
  • Is any DTC present? 
 Yes Go to applicable DTC inspection. See DIAGNOSTIC TROUBLE CODE (DTC) INDEX - POWERTRAIN CONTROL MODULE (PCM) .
No Troubleshooting is complete.
CRANKSHAFT POSITION (CKP) SENSOR MALFUNCTION 
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