Engine will not start, engine starts but stalls immediately, or engine is hard to start

Special Tools Required 

Vacuum Pump/Gauge, 0-30 inHg Snap-on YA4000A or equivalent, commercially available

NOTE: 

• Before beginning this troubleshooting, ask a customer about diagnostic interview - Refer to: Fuel and Emissions Systems Symptom Troubleshooting - Engine stalls-Diagnostic interview 
• • When the symptom cannot be duplicated, you can do the troubleshooting using the on-board snapshot information in this procedure. Refer to the diagnostic interview (date, place) and the present total mileage, and compare the total mileage which is estimated from the interview when a failure occurred and the parameter (total mileage) in the on-board snapshot information. Make sure the date when the failure occurred corresponds with the date on which the on-board snapshot information was recorded. If it doesn't, the on-board snapshot information cannot be used in this troubleshooting.
• Before beginning this troubleshooting:
• • Make sure the battery is fully charged.
  • Make sure the fuel tank is at least 1/4 full.
  • Make sure the engine oil level is correct.
• After the troubleshooting, reset the PCM with the HDS to certainly erase the on-board snapshot information recorded on the PCM.

1. DTC check

   - 1. Turn the vehicle to the ON mode.

   - 2. Check for Pending or Confirmed DTCs with the HDS.

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame

   Are any Pending or Confirmed DTCs indicated?

   YES 

   Go to the indicated DTC's troubleshooting.

   NO 

   Go to step 2.

   NOTE:  If the HDS does not communicate with the PGM-FI system, go to the PCM power and ground circuit troubleshooting - Refer to: PCM Power and Ground Circuit Troubleshooting (2014 2015), or PCM Power and Ground Circuit Troubleshooting (2016), or PCM Power and Ground Circuit Troubleshooting (2017 2018 2019 2020) .

2. Immobilizer system check

   - 1. Check the status log of the immobilizer system.

   NOTE:  When a status log count is found, it means the immobilizer system has kept the engine from starting in the past. The number of status log count shows how often the immobilizer system has kept the engine from starting in the past. If the immobilizer system has no status log count, the system is normal.

   Was the status log count found?

   YES 

   Check for probable cause of the status log .

   NO 

   Go to step 3.

3. Problem verification (snapshot sampling)

   - 1. Set the HDS to record a 30 second manual trigger SNAPSHOT with the trigger in the middle.

   • IMMOBILIZER
   • ENGINE SPEED
   • BATTERY
   • ECT SENSOR 1
   • MAP SENSOR
   • MAF SENSOR
   • FUEL PRESSURE CONVERTED FROM PF SENSOR
   • FUEL PRESSURE DIRECT INJECTION SYSTEM
   • CMP B NO PULSE
   • CMP B NOISE
   • CKP NO PULSE
   • CKP NOISE
   • EGR valve position sensor (EGR VLS)
   • VTEC PRES SW

   Data List

   - 2. Begin the snapshot, then try to start the engine.

   Is the engine hard to start?

   YES 

   Go to step 6 (diagnosis by parameter troubleshooting).

   NO 

   Go to step 4.

4. On-board snapshot check (Engine will not start)

   - 1. Check record of Hard to Start Engine in the on-board snapshot with the HDS.

   On-board Snapshot

   Is the Hard to Start Engine in the on-board snapshot recorded?

   YES 

   Go to step 6 (diagnosis by parameter troubleshooting).

   NO 

   Go to step 5.

5. On-board snapshot check (Engine Stall 2):

   NOTE:  When Hard to Start on-board snapshot data was not recorded, use the Engine Stall 2 on-board snapshot data and check the cause of the failure.

   - 1. Check record of Engine Stall 2 in the on-board snapshot with the HDS.

   On-board Snapshot

   Is an Engine Stall 2 on-board snapshot recorded?

   YES 

   Go to step 20 (diagnosis by parameter (ST FUEL TRIM (B1, B2))).

   NO 

   Go to step 22 (fuel system troubleshooting).

   NOTE:  In case of the following conditions, the on-board snapshot will not be recorded when engine stalls.

   • The vehicle is turned to the OFF (LOCK) mode, after starting the engine.
   • Vehicle condition is not in the on-board snapshot recoding zone of Hard to start engine (see the gray zone of following graph).
   • Low or dead battery
   • The battery is disconnected

   ECT SENSOR 1 (°F (°C))	-40 (-40)	-22 (-30)	-13 (-25)	-4 (-20)	5 (-15)	14 (-10)	194 (90)
   Start time (sec)	6.0	6.0	3.0	2.25	1.5	1.5	1.5

   Courtesy of HONDA, U.S.A., INC.

6. On-board snapshot or snapshot check (IMMOBILIZER):

   NOTE:  Use the on-board snapshot in the case of an intermittent failure, or use the snapshot in the case of a reproducible failure.

   - 1. Select the Hard to Start Engine in the on-board snapshot or snapshot with the HDS.

   On-board Snapshot

   - 2. Select the IMMOBILIZER and ENGINE SPEED in the configuration list.

   Compare the snapshot parameters observed while the engine was cranking, to those in the chart below, to determine the problem.

   Pattern	Symptom (Diagnosis by parameter)	Additional remarks
   Pattern 1	IMMOBILIZER inhibit Courtesy of HONDA, U.S.A., INC.HONDA, U.S.A., INC. IMMOBILIZER inhibit Courtesy of HONDA, U.S.A., INC.HONDA, U.S.A., INC.	When IMMOBILIZER indicates "BAN" during cranking or after start, the fuel pump is stopped by IMMOBILIZER inhibit. No failure in the engine

   Pattern	Symptom (Diagnosis by parameter)	Additional remarks
   Pattern 2	IMMOBILIZER permit Normal Courtesy of HONDA, U.S.A., INC.HONDA, U.S.A., INC. IMMOBILIZER permit Normal Courtesy of HONDA, U.S.A., INC.HONDA, U.S.A., INC.	IMMOBILIZER is normal when IMMOBILIZER indicates "RUN" when cranking or after start.

   Which pattern is indicated?

   Pattern 1

   The immobilizer system has a failure. Go to the keyless access (immobilizer) System Check - Refer to: Keyless Access System Check (2014 2015), or Keyless Access System Check (2016 2017 2018 2019 2020) .

   Pattern 2

   The immobilizer system is OK. Go to step 7 (diagnosis by parameter (ENGINE SPEED)).

7. On-board snapshot or snapshot check (ENGINE SPEED):

   NOTE:  Use the on-board snapshot in the case of an intermittent failure, or use the snapshot in the case of a reproducible failure.

   - 1. Select the Hard to Start Engine in the on-board snapshot or snapshot with the HDS.

   On-board Snapshot

   - 2. Select the ENGINE SPEED pattern chart in the configuration list.

   Check the recorded snapshot parameters while the engine is cranking, then compare the pattern from the chart, and determine the problem.

   Pattern	Symptom (Diagnosis by parameter)	Additional remarks
   Pattern 1	ENGINE SPEED when cranking is normal Courtesy of HONDA, U.S.A., INC.
   Pattern 2	ENGINE SPEED when cranking is low Courtesy of HONDA, U.S.A., INC.	When ENGINE SPEED during cranking is under 90 rpm, weak battery or increased engine friction can be considered.

   Which pattern is indicated?

   Pattern 1

   The engine cranking speed is OK. Go to step 8 (diagnosis by parameter (BATTERY)).

   Pattern 2

   Diagnostic procedure.

   • 1.

     Test the battery - Refer to: Battery Test (2014 2015), or Battery Test (2016 2017 2018 2019 2020) .

   • 2.

     Check the battery cables and the connections.

   • 3.

     Check the starter - Refer to: Starter Removal, Installation, and Performance Test (2016 2017 2018 2019 2020) or Starter Removal, Installation, and Performance Test (2014 2015) .

   • 4.

     Check for engine friction.

8. On-board snapshot or snapshot check (BATTERY):

   NOTE:  Use the on-board snapshot in the case of an intermittent failure, or use the snapshot in the case of a reproducible failure.

   - 1. Select the Hard to Start Engine in the on-board snapshot or snapshot with the HDS.

   On-board Snapshot

   - 2. Select the BATTERY and ENGINE SPEED in the configuration list.

   Check the recorded snapshot parameters while the engine is cranking, then compare the BATTERY pattern from the chart, and determine the problem.

   Pattern	Symptom (Diagnosis by parameter)	Additional remarks
   Pattern 1	BATTERY voltage low when cranking Courtesy of HONDA, U.S.A., INC.	When BATTERY voltage during cranking is too low, there is a possibility that PCM and/or the engine will not start. The PCM and other system control units require 7.0 V or more to start.
   Pattern 2	BATTERY voltage normal when cranking Courtesy of HONDA, U.S.A., INC.	To start the engine, 7.0 V or more is needed

   Which pattern is indicated?

   Pattern 1

   Diagnostic procedure.

   • 1.

     Test the battery - Refer to: Battery Test (2014 2015), or Battery Test (2016 2017 2018 2019 2020) .

   • 2.

     Check the battery cables and the connections.

   Pattern 2

   The battery is OK. Go to step 9 (diagnosis by parameter (ECT SENSOR 1)).

9. On-board snapshot or snapshot check (ECT SENSOR 1):

   NOTE:  Use the on-board snapshot in the case of an intermittent failure, or use the snapshot in the case of a reproducible failure.

   - 1. Select the Hard to Start Engine in the on-board snapshot or snapshot with the HDS.

   On-board Snapshot

   - 2. Select ECT SENSOR 1 and ENGINE SPEED in the configuration list.

   Check the recorded snapshot parameters while the engine is cranking, then compare the ECT SENSOR 1 pattern from the chart, and determine the problem.

   Pattern	Symptom (Diagnosis by parameter)	Additional remarks
   Pattern 1	ECT SENSOR 1 high when cranking Courtesy of HONDA, U.S.A., INC.	When ECT SENSOR 1 indicates about 176 °F (80 °C) or more when the engine is cold (engine temp low), ECT sensor 1 may be stuck high. ECT compensation is not applied after the engine is warmed up, it is not necessary to check ECT sensor 1 (not a faulty part).
   Pattern 2	ECT SENSOR 1 normal when cranking Courtesy of HONDA, U.S.A., INC.	If actual engine temp is nearly the same as the temp detected by ECT sensor 1 when cranking, ECT sensor 1 is normal.

   Which pattern is indicated?

   Pattern 1

   Check for a short in ECT sensor 1 circuit and a failure in ECT sensor 1.

   Pattern 2

   ECT sensor 1 is OK. Go to step 10 (diagnosis by parameter (MAP SENSOR)).

10. On-board snapshot or snapshot check (MAP SENSOR):

    NOTE:  Use the on-board snapshot in the case of an intermittent failure, or use the snapshot in the case of a reproducible failure.

    - 1. Select the Hard to Start Engine in the on-board snapshot or snapshot with the HDS.

    On-board Snapshot

    - 2. Select the MAP SENSOR and ENGINE SPEED in the configuration list.

    Check the recorded snapshot parameters while the engine is cranking, then compare the MAP SENSOR pattern to the pattern from the chart below, and determine the problem.

    Pattern	Symptom (Diagnosis by parameter)	Additional remarks
    Pattern 1	MAP SENSOR detects no change of pressure when cranking Courtesy of HONDA, U.S.A., INC.	When MAP SENSOR detects no change of pressure when cranking, the pressure measurement port may be clogged. The PCM decides basic duration time of fuel injection from engine speed and MAP sensor signal when cranking.
    Pattern 2	Normal when MAP SENSOR detects vacuum when cranking Courtesy of HONDA, U.S.A., INC.	When MAP SENSOR detects vacuum while cranking, the condition is normal and the MAP sensor pressure port is clear.

    Which pattern is indicated?

    Pattern 1

    Check the pressure measurement port of the MAP sensor for clogging, foreign objects, plugged exhaust, etc.

    Pattern 2

    The MAP sensor is OK. Go to step 11 (diagnosis by parameter (MAF SENSOR)).

11. On-board snapshot or snapshot check (MAF SENSOR):

    NOTE:  Use the on-board snapshot in the case of an intermittent failure, or use the snapshot in the case of a reproducible failure.

    - 1. Select the Hard to Start Engine in the on-board snapshot or snapshot with the HDS.

    - 2. Select the MAF SENSOR and ENGINE SPEED in the configuration list.

    Check the recorded snapshot or on-board snapshot parameters while the engine is cranking, then compare the MAF SENSOR pattern from the chart, and determine the problem.

    Pattern	Symptom (Diagnosis by parameter)	Additional remarks
    Pattern 1	Poor connection of MAF SENSOR Courtesy of HONDA, U.S.A., INC.	Complete combustion stall: When MAF SENSOR indicates "0" 1-2 sec before ENGINE SPEED becomes 0 rpm, or when "0" is shown like noise, there may be a poor connection at the MAF SENSOR connector.
    Pattern 2	MAF SENSOR output incorrect Courtesy of HONDA, U.S.A., INC.	When MAF SENSOR shows "0" when cranking or after start, clogging in MAF SENSOR's measurement port may be contaminated with debris or there may be a poor connection as its connector.
    Pattern 3	MAF SENSOR Normal Courtesy of HONDA, U.S.A., INC.	When MAF SENSOR output compares with ENGINE SPEED when cranking or after starting, MAF SENSOR is normal.

    Which pattern is indicated?

    Pattern 1 and 2

    Check for loose terminals or a poor connection at the MAF SENSOR.

    Pattern 3

    The MAF sensor/IAT sensor is OK. Go to step 12 (diagnosis by parameter (FUEL PRESSURE CONVERTED FROM PF SENSOR and FUEL PRESSURE DIRECT INJECTION SYSTEM (TERGET FUEL PRESSURE))).

12. On-board snapshot or snapshot check (FUEL PRESSURE CONVERTED FROM PF SENSOR and FUEL PRESSURE DIRECT INJECTION SYSTEM (TERGET FUEL PRESSURE)):

    NOTE:  Use the on-board snapshot in the case of an intermittent failure, or use the snapshot in the case of a reproducible failure.

    - 1. Select the Hard to Start Engine in the on-board snapshot or snapshot with the HDS.

    On-board Snapshot

    - 2. Select the FUEL PRESSURE CONVERTED FROM PF SENSOR, the FUEL PRESSURE DIRECT INJECTION SYSTEM (TERGET FUEL PRESSURE), and ENGINE SPEED in the configuration list.

    Check the recorded snapshot or on-board snapshot parameters while the engine is cranking, then compare the FUEL PRESSURE CONVERTED FROM PF SENSOR and FUEL PRESSURE DIRECT INJECTION SYSTEM (TERGET FUEL PRESSURE) patterns from the chart, and determine the problem.

    Pattern	Symptom (Diagnosis by parameter)	Additional remarks
    Pattern 1	The FUEL PRESSURE CONVERTED FROM PF SENSOR is low (almost 0 kPa) when cranking Courtesy of HONDA, U.S.A., INC.	If the FUEL PRESSURE CONVERTED FROM PF SENSOR is almost 0 kPa when cranking, a failure may exist in the fuel supply system. Fuel leak, out of fuel Fuel rail pressure sensor failure Spill valve stuck off Fuel pressure regulator (low pressure side) Fuel pump (low pressure side) High pressure fuel pump
    Pattern 2	Normal when the FUEL PRESSURE CONVERTED FROM PF SENSOR follows the FUEL PRESSURE DIRECT INJECTION SYSTEM when cranking Courtesy of HONDA, U.S.A., INC.	If the FUEL PRESSURE CONVERTED FROM PF SENSOR is nearly the same as the FUEL PRESSURE DIRECT INJECTION SYSTEM (TERGET FUEL PRESSURE) when cranking, the fuel pressure is normal. Fuel pressure may be low when the start of cranking.

    Which pattern is indicated?

    Pattern 1

    Do the troubleshooting procedure for DTC P0087 .

    Pattern 2

    The fuel pressure is OK. Go to step 13 (diagnosis by parameter (CMP B NO PULSE)).

13. On-board snapshot or snapshot check (CMP B NO PULSE):

    NOTE:  Use the on-board snapshot in the case of an intermittent failure, or use the snapshot in the case of a reproducible failure.

    - 1. Select the Hard to Start Engine in the on-board snapshot or snapshot with the HDS.

    On-board Snapshot

    - 2. Select the CMP B NO PULSE and ENGINE SPEED in the configuration list.

    Check the recorded snapshot parameters while the engine is cranking, then compare the CMP B NO PULSE pattern from the chart, and determine the problem.

    Pattern	Symptom (Diagnosis by parameter)	Additional remarks
    Pattern 1	Count is continuously up Courtesy of HONDA, U.S.A., INC.	When CMP B NO PULSE count increase when cranking, no CMP pulse is received. If the CMP pulse is not received, the PCM cannot detect the cylinder to be ignited and the engine is unable to start.
    Pattern 2	Count is continuously not up Courtesy of HONDA, U.S.A., INC.	Count is not up continuously during cranking.

    Which pattern is indicated?

    Pattern 1

    Do the troubleshooting procedure for DTC P0365 . If the CMP B NO PULSE count reaches the malfunction threshold, DTC P0365 will set. Check for poor connections and loose terminals at the CMP sensor.

    Pattern 2

    Go to step 14 (diagnosis by parameter (CMP B NOISE)).

14. On-board snapshot or snapshot check (CMP B NOISE):

    NOTE:  Use the on-board snapshot in the case of an intermittent failure, or use the snapshot in the case of a reproducible failure.

    - 1. Select the Hard to Start Engine in the on-board snapshot or snapshot with the HDS.

    On-board Snapshot

    - 2. Select the CMP B NOISE and ENGINE SPEED in the configuration list.

    Check the recorded snapshot parameters while the engine is cranking, then compare the CMP B NOISE pattern from the chart, and determine the problem.

    Pattern	Symptom (Diagnosis by parameter)	Additional remarks
    Pattern 1	Count is continuously up Courtesy of HONDA, U.S.A., INC.	When CMP B NOISE count increases when cranking, there is noise in the CMP signal. When CMP signal has noise, the PCM cannot detect the cylinder to be ignited and the engine is unable to start.
    Pattern 2	Count is continuously not up Courtesy of HONDA, U.S.A., INC.	Count is not up continuously during cranking.

    Which pattern is indicated?

    Pattern 1

    Do the troubleshooting procedure for DTC P0369 . If the CMP B NOISE count reaches the malfunction threshold, DTC P0369 will set. Check for poor connections and loose terminals at the CMP sensor.

    Pattern 2

    The CMP sensor is OK. Go to step 15 (diagnosis by parameter (CKP NO PULSE)).

15. On-board snapshot or snapshot check (CKP NO PULSE):

    NOTE:  Use the on-board snapshot in the case of an intermittent failure, or use the snapshot in the case of a reproducible failure.

    - 1. Select the Hard to Start Engine in the on-board snapshot or snapshot with the HDS.

    On-board Snapshot

    - 2. Select the CKP NO PULSE and ENGINE SPEED in the configuration list.

    Check the recorded snapshot parameters while the engine is cranking, then compare the CKP NO PULSE pattern from the chart, and determine the problem.

    Pattern	Symptom (Diagnosis by parameter)	Additional remarks
    Pattern 1	Count is continuously up Courtesy of HONDA, U.S.A., INC.	When the CKP NO PULSE count increases when cranking, the PCM is not receiving the correct CKP pulse.
    Pattern 2	Count is continuously not up Courtesy of HONDA, U.S.A., INC.	Count is not up continuously during cranking.

    Which pattern is indicated?

    Pattern 1

    Do the troubleshooting procedure for DTC P0335 . If the CKP NO PULSE count reaches the malfunction threshold, DTC P0335 will set. Check for poor connections and loose terminals at the CKP sensor.

    Pattern 2

    Go to step 16 (diagnosis by parameter (CKP NOISE)).

16. On-board snapshot or snapshot check (CKP NOISE):

    NOTE:  Use the on-board snapshot in the case of an intermittent failure, or use the snapshot in the case of a reproducible failure.

    - 1. Select the Hard to Start Engine in the on-board snapshot or snapshot with the HDS.

    On-board Snapshot

    - 2. Select the CKP NOISE and ENGINE SPEED in the configuration list.

    Check the recorded snapshot parameters while the engine is cranking, then compare the CKP NOISE pattern from the chart, and determine the problem.

    Pattern	Symptom (Diagnosis by parameter)	Additional remarks
    Pattern 1	Count is continuously up Courtesy of HONDA, U.S.A., INC.	When the CKP NOISE count increases when cranking, the PCM is not receiving the correct CKP pulse.
    Pattern 2	Count is continuously not up Courtesy of HONDA, U.S.A., INC.	Count is not up continuously during cranking.

    Which pattern is indicated?

    Pattern 1

    Do the troubleshooting procedure for DTC P0339 . If the CKP NOISE count reaches the malfunction threshold, DTC P0339 will set. Check for poor connections and loose terminals at the CKP sensor, and also check for aftermarket accessories.

    Pattern 2 (Reproducible failure)

    The CKP sensor is OK. Go to step 17 (diagnosis by parameter (EGR valve position sensor (EGR VLS))).

    Pattern 2 (Intermittent failure)

    The CKP sensor is OK. Go to step 19 (diagnosis by parameter (Engine Stall 2)).

17. Snapshot check (EGR valve position sensor (EGR VLS))

    - 1. Select the Hard to Start Engine in the on-board snapshot or snapshot with the HDS.

    - 2. Select the EGR valve position sensor (EGR VLS) and ENGINE SPEED in the configuration list.

    Check the recorded snapshot parameters while the engine is cranking, then compare the EGR valve position sensor (EGR VLS) pattern from the chart, and determine the problem.

    Pattern	Symptom (Diagnosis by parameter)	Additional remarks
    Pattern 1	EGR valve position sensor (EGR VLS) is 1.3 V or more Courtesy of HONDA, U.S.A., INC.	When EGR valve position sensor (EGR VLS) voltage during cranking is about 1.3 V or more, the engine start time is longer than normal condition
    Pattern 2	EGR valve position sensor (EGR VLS) indicates the EGR is normal Courtesy of HONDA, U.S.A., INC.	EGR valve position sensor (EGR VLS) voltage during cranking is less than 1.3 V, the EGR valve position sensor is normal

    Which pattern is indicated?

    Pattern 1

    Loosen the EGR valve mounting bolts , then install a metal plate between the EGR valve and the engine to block the EGR port. Recheck the engine start time. If the engine start time is normal, there is a failure in the EGR valve.

    Pattern 2 (Reproducible failure)

    The EGR valve is OK. Go to step 18 (diagnosis by parameter (VTEC PRES SW in the on-board snapshot)).

    Pattern 2 (Intermittent failure)

    The EGR valve is OK. Go to step 19 (diagnosis by parameter (Engine Stall 2)).

18. Snapshot check (VTEC PRES SW)

    - 1. Check the parameter (s) below with the HDS.

    Signal	Threshold		Current conditions
    	Values	Unit	Values	Unit
    ROCKER ARM OIL PRESSURE SWITCH A (BANK 1)	ON
    ROCKER ARM OIL PRESSURE SWITCH A (BANK 2)	ON

    Do the current condition (s) match the threshold?

    YES 

    Substitute a known-good front rocker arm oil control valve - Refer to: Front Rocker Arm Oil Control Valve Removal and Installation, or a known-good rear rocker arm oil control valve - Refer to: Rear Rocker Arm Oil Control Valve Removal and Installation . If the valves are OK, replace the oil pump .

    NO 

    The rocker arm oil pressure switches are OK. Go to step 22 (Fuel system troubleshooting).

19. On-board snapshot check (Engine Stall 2)

    - 1. Check for a record of Engine Stall 2 in the on-board snapshot with the HDS.

    On-board Snapshot

    Is Engine Stall 2 as on-board snapshot recorded?

    YES 

    Go to step 20 (diagnosis by parameter (ST FUEL TRIM (B1, B2))).

    NO 

    Go to step 22 (fuel system troubleshooting).

20. On-board snapshot check (ST FUEL TRIM (B1, B2))

    - 1. Check for a record of Engine Stall 2 in the on-board snapshot with the HDS.

    On-board Snapshot

    - 2. Select the ST FUEL TRIM (B1, B2) and ENGINE SPEED in the configuration list.

    Check the recorded snapshot parameters at the time of engine stalls, then compare the ST FUEL TRIM (B1, B2) pattern from the chart, and determine the problem.

    Pattern	Symptom (Diagnosis by parameter)	Additional remarks
    Pattern 1	Engine stalls while ST FUEL TRIM (B1, B2) value increasing Courtesy of HONDA, U.S.A., INC.	If the engine stalls while ST FUEL TRIM (B1, B2) value is increasing, a failure may exist in the fuel system.

    Pattern	Symptom (Diagnosis by parameter)	Additional remarks
    Pattern 2	Normal when the engine stalls when ST FUEL TRIM (B1, B2) is around 1.0 (center value) Courtesy of HONDA, U.S.A., INC.	The fuel system is normal when the engine stalls with ST FUEL TRIM (B1, B2) around 1.0 (center value).

    Which pattern is indicated?

    1. Pattern 1

       Diagnostic procedure.

       • 1.

         Check the fuel pump operation sound.

       • 2.

         Go to the fuel pressure test .

       • 3.

         Go to DTC P0627 for the fuel pump circuit troubleshooting .

       • 4.

         Test PGM-FI main relay 1 - Refer to: Power Relay Test (2016 2017 2018 2019 2020), or Power Relay Test (2014 2015) .

       • 5.

         Test PGM-FI main relay 2 - Refer to: Power Relay Test (2014 2015), or Power Relay Test (2016 2017 2018 2019 2020) .

       • 6.

         Check for the following fuses:

       • • No. C10 (15 A) fuse (in the under-hood fuse/relay box)
         • No. D21 (20 A) fuse (in the driver's under-dash fuse/relay box)

       Pattern 2

       Go to step 21 (diagnosis by parameter (MISFIRE)).

21. On-board snapshot check (MISFIRE)

    - 1. Check for a record of Engine Stall 2 in the on-board snapshot with the HDS.

    On-board Snapshot

    - 2. Select the MISFIRE and ENGINE SPEED in the configuration list.

    Check the recorded snapshot parameters at the time of the engine stalls, then compare those snapshots to the MISFIRE pattern from the chart, and determine the problem.

    Pattern	Symptom (Diagnosis by parameter)	Additional remarks
    Pattern 1	Engine stalls after MISFIRE counts increase Courtesy of HONDA, U.S.A., INC.	If the engine stalls after MISFIRE count increases, the engine stall may be caused by misfire. Also the misfire may be caused by a loss of compression, faulty ignition system, faulty fuel system, etc.
    Pattern 2	Normal when engine stalls with MISFIRE count remaining constant Courtesy of HONDA, U.S.A., INC.	If the MISFIRE count remains steady when the engine stalls, the stall was not caused by a misfire.

    Which pattern is indicated?

    Pattern 1

    Diagnostic procedure.

    • 1.

      If misfire counts go up without storing misfire DTC P0300 - P0306, go to DTC P0300 - P0306 troubleshooting .

    • 2.

      If the misfire count reaches the malfunction threshold, DTC P0300 - P0306 is stored. Go to the DTC P0300 - P0306 troubleshooting .

    Pattern 2

    Go to step 22 (fuel system troubleshooting).

22. Fuel pressure check

    - 1. Do the fuel pressure test.

    Is the fuel pressure OK?

    YES 

    Go to step 23 (ignition system troubleshooting).

    NO 

    Check the following parts:

    • Go to the fuel pump circuit troubleshooting procedure for DTC P0627 .
    • Fuel pressure regulator
    • Fuel filter
23. Spark plug visual check

    - 1. Turn the vehicle to the OFF (LOCK) mode.

    - 2. Remove the spark plugs.

    - 3. Check the condition of the spark plug electrodes.

    NOTE:  Make sure the spark plugs are the correct part number for the vehicle. If the plugs are aftermarket or they are not the correct part number, replace all of the plugs and retest.

    Is the electrode damage or wet?

    1. YES (wet)

       Check the following conditions. If those conditions do not apply, go to step 24.

       • In very cold conditions, multiple very short trips can cause the spark plug to foul. If this is the case, drive the vehicle a longer distance and recheck.
       • Incorrect or poor quality fuel can cause a wet spark plug. Replace the fuel and recheck.

       YES (damaged)

       Replace the damaged spark plugs , determine the cause of the spark plug damage.

       NO 

       Go to step 24.

24. Determine possible failure area (ignition system, others)

    - 1. Select ALL INJECTORS in the INSPECTION MENU with the HDS, and stop fuel injection operation.

    ALL INJECTORS

    Fit a spark plug to the ignition coil and ground it to the engine.

    - 3. Crank the engine and watch for spark at the spark plug.

    Does it have sparkΩ

    YES 

    The ignition system is OK. Select PCM reset in the PGM-FI INSPECTION MENU to cancel ALL INJECTORS STOP with the HDS, then go to step 26 (engine compression troubleshooting).

    NO 

    Go to step 25.

25. Ignition coil power circuit check

    - 1. Disconnect the following connector (s).

    Ignition coil 3P connector (problem cylinder)

    - 2. Turn the vehicle to the ON mode.

    - 3. Measure the voltage between test points 1 and 2.

    Test condition	Vehicle ON mode
    	Ignition coil 3P connector (problem cylinder): disconnected
    Test circuit	IG (IGN COIL)
    Test point 1	Ignition coil 3P connector No. 1 (RED)
    Test point 2	Body ground

    Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    The ignition coil power circuit is OK. Replace the ignition coil (s) .

    NO 

    Repair the ignition coil power circuit.

26. Engine compression check

    - 1. Do an engine compression inspection.

    Is engine compression OK?

    YES 

    Go to step 27 (EVAP canister purge valve check).

    NO 

    Check for wear or damage to these parts:

    • Incorrect valve clearance
    • Confirmation of cam timing
    • Oil pressure relief valve
    • Damage or worn cam lobes
    • Damage or worn valve and seats
    • Damage cylinder head gasket
    • Damage or worn piston rings
    • Damage or worn piston and cylinder bore
27. EVAP canister purge valve check

    - 1. Turn the vehicle to the OFF (LOCK) mode.

    - 2. Disconnect the following connector.

    EVAP canister purge valve 2P connector

    - 3. Disconnect the vacuum hose (A) from the EVAP canister purge valve (B) in the engine compartment, and connect the vacuum pump/gauge, 0 - 30 inHg, to the purge line.

    Courtesy of HONDA, U.S.A., INC.

    - 4. Start the engine.

    Does the vacuum gauge indicate vacuum?

    YES 

    Replace the EVAP canister purge valve .

    NO (Reproducible failure)

    Go to step 28 (fuse check).

    NO (Intermittent failure)

    Go to step 29 (relay check).

28. Fuse check

    - 1. Check the following fuses.

    Fuse	No. C8 (15 A) to the PGM-FI subrelay
    Fuse	No. C10 (15 A) to PGM-FI main relay 1
    Fuse	No. C11 (15 A) to the ignition coil relay
    Fuse	No. C14 (20 A) to the injector relay
    Location	Under-hood fuse/relay box

    Fuse	No. D21 (20 A) to PGM-FI main relay 2
    Location	Driver's under-dash fuse/relay box

    Are the fuses OK?

    YES 

    The fuses are OK. Go to step 29 (relay check).

    NO 

    Replace the blown fuse (s).

29. Relay check

    - 1. Test the following relays:

    NOTE:  In case the failure is not reproduced, the following relays may have an intermittent failure.

    • PGM-FI main relay 1
    • PGM-FI main relay 2
    • PGM-FI subrelay
    • Ignition coil relay
    • Injector relay

    Are the relays OK?

    YES 

    Go to the Diagnostic Interview - Refer to: Fuel and Emissions Systems Symptom Troubleshooting - Engine stalls-Diagnostic interview 

    NO 

    Replace any defective relays.