Fuel and Emissions Systems Symptom Troubleshooting - Engine stalls (V6)

Fuel and Emissions Systems Symptom Troubleshooting - Engine stalls

Engine stalls

Special Tools Required

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

NOTE:

Before beginning this troubleshooting, do a customer 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 occured and the parameter (total mileage) in the on-board snapshot information. Make sure the date when the failure occured 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 erase the on-board snapshot information recorded on the PCM.

DTC check:

DTC check

?1.	Press the engine start/stop button to select 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 vehicle, go to the PCM power and ground circuit troubleshooting.

Problem verification:

Problem verification

?1.

Set the HDS to record a HIGH-SPEED SNAPSHOT of following parameters for 30 seconds.

	ENGINE SPEED
	MAF SENSOR
	ECT SENSOR 1
	BATTERY
	CKP NO PULSE
	CKP NOISE
	ST FUEL TRIM B1
	ST FUEL TRIM B2
	EVAP PC DUTY
	MISFIRE
	EGR valve position sensor (EGR VLS)
	EGR L COMMAND
	A/C CLUTCH
	PNP SWITCH (A/T)
	SLIP RATIO OF TORQ OR STARTCLUTCH (A/T)

?2.	Begin the snapshot, then start the engine and let it idle without load (A/T in P or N, M/T in neutral).

Did the engine stall?


	YES

Go to step 4 (diagnosis by parameter (MAF SENSOR)).


	NO

Go to step 3.

On-board snapshot check:

On-board snapshot check

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

Is there an Engine Stall 2 record in the on-board snapshot?


	YES

Go to step 4 (diagnosis by parameter (MAF SENSOR)).


	NO

Go to step 15 (fuel system troubleshooting).

NOTE: If an engine stall on-board snapshot was not found, the snapshot may have been lost due to low battery voltage or because of battery disconnection or replacement.

On-board snapshot check (MAF SENSOR):

On-board 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.	Check for a record of Engine Stall 2 in the on-board snapshot or the recorded 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 at the time of the engine stall, then compare the MAF SENSOR pattern from the charts, and determine the problem.

Pattern	Symptom (Diagnosis by parameter)	Additional remarks
Pattern 1	Poor connection of MAF SENSOR	If the engine stalls 1?2 seconds after MAF SENSOR shows "0"g/s the engine stall may be caused by a faulty MAF sensor, poor connection, or electrical noise in the MAF sensor signal.
Pattern 2	MAF SENSOR Normal	When the MAF SENSOR pattern matches ENGINE SPEED, the MAF sensor is normal.

Which pattern is indicated?


	Pattern 1

Check the MAF sensor/IAT sensor for loose terminals or poor connections. If the terminals and connections are OK, substitute a known-good MAF sensor/IAT sensor.


	Pattern 2

The MAF sensor/IAT sensor is OK. Go to step 5 (diagnosis by parameter (ECT SENSOR 1)).

On-board snapshot check (ECT SENSOR 1):

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

?2.

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

Check the recorded snapshot or on-board snapshot parameters at the time of the engine stall, then compare ECT SENSOR 1 pattern from the charts, and determine the problem.

Pattern	Symptom (Diagnosis by parameter)	Additional remarks
Pattern 1	ECT SENSOR 1 high	When ECT SENSOR 1 indicates about 176 °F (80 °C) or more when the engine is actually cold, ECT sensor 1 signal may be stuck high. If this occurs, the PCM may not properly compensate for cold engine operation, causing the engine to stall.
Pattern 2	ECT SENSOR 1 normal	If actual engine temp is similar to ECT SENSOR 1, 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 6 (diagnosis by parameter (BATTERY)).

On-board snapshot check (BATTERY):

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

?2.

Select the BATTERY and ENGINE SPEED in the configuration list.

Check the recorded snapshot or on-board snapshot parameters at the time of the engine stall, then compare the BATTERY pattern from the charts, and determine the problem.

Pattern

Symptom (Diagnosis by parameter)

Additional remarks

Pattern 1

BATTERY voltage low

	When the BATTERY voltage is excessively low, the PCM or control unit stops functioning, causing engine stall.
	For PCM or each control unit to start (functioning), more than 7.0 V is needed.

Pattern 2

BATTERY voltage normal

If the BATTERY voltage is above 12 V when the engine stalls, the battery is normal.

Which pattern is indicated?


	Pattern 1

Test the battery, and check the battery cables and terminals


	Pattern 2

The battery is OK. Go to step 7 (diagnosis by parameter (CKP NO PULSE)).

On-board snapshot check (CKP NO PULSE):

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

?2.

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

Check the recorded snapshot or on-board snapshot parameters at the time of the engine stall, then compare the CKP NO PULSE pattern from the charts, and determine the problem.

Pattern	Symptom (Diagnosis by parameter)	Additional remarks
Pattern 1	CKP NO PULSE counts go up when cranking	When CKP NO PULSE counts go up, the PCM is not receiving the CKP sensor signal.
Pattern 2	The CKP NO PULSE indicates the pulse is normal	The CKP sensor signal is OK when the CKP NO PULSE count does not increase.

Which pattern is indicated?


	Pattern 1

Do the troubleshooting procedure for DTC P0335.


	Pattern 2

Go to step 8 (diagnosis by parameter (CKP NOISE)).

On-board snapshot check (CKP NOISE):

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

?2.

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

Check the recorded snapshot or on-board snapshot parameters at the time of the engine stall, then compare the CKP NOISE pattern from these charts, and determine the problem.

Pattern	Symptom (Diagnosis by parameter)	Additional remarks
Pattern 1	CKP NOISE counts go up	When CKP NOISE counts go up, the PCM is receiving electrical noise along with the CKP sensor signal.
Pattern 2	Normal when CKP NOISE count does not go up	The CKP sensor signal is OK when the CKP NOISE count does not increase.

Which pattern is indicated?


	Pattern 1

Go to the troubleshooting procedure for DTC P0339.


	Pattern 2

The CKP sensor is OK. Go to step 9 (diagnosis by parameter (ST FUEL TRIM (B1, B2))).

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

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

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

?2.

Select the ST FUEL TRIM (B1, B2), EVAP PC DUTY, and ENGINE SPEED in the configuration list.

Check the recorded snapshot or on-board snapshot parameters at the time of the engine stall, then compare the ST FUEL TRIM (B1, B2) pattern from the charts, and determine the problem.

Pattern	Symptom (Diagnosis by parameter)	Additional remarks
Pattern 1	Engine stalls while ST FUEL TRIM (B1, B2) value increases	If the ST FUEL TRIM (B1, B2) value increases when the engine stalls, there may be a lean condition.
Pattern 2	Normal when the engine stalls when ST FUEL TRIM (B1, B2) is around 1.0 (center value)	The fuel trim is normal when the engine stalled with ST FUEL TRIM (B1, B2) around 1.0 (center value).
Pattern 3	Engine stalls when ST FUEL TRIM (B1, B2) is around 0.8	When the value of ST FUEL TRIM (B1, B2) is around 0.8, the PCM commands the purge control solenoid (PCS) to close (closed when EVAP PC DUTY is 0 %). If the ST FUEL TRIM (B1, B2) does not move toward 1.0, the PCS may be leaking.
Pattern 4	Normal when the engine stalls with ST FUEL TRIM (B1, B2) is around 1.0 (center value)	When the value of ST FUEL TRIM (B1, B2) is around 0.8, the PCM commands the purge control solenoid (PCS) to close (closed when EVAP PC DUTY is 0 %). If the ST FUEL TRIM (B1, B2) moves toward 1.0, the PCS is no leaking.

Which pattern is indicated?


	Pattern 1

Diagnostic procedure:

Check the fuel pump operation sound.

Go to the fuel pressure test.

Go to DTC P0627 for the fuel pump circuit troubleshooting.

Test PGM-FI main relay 1.

Test PGM-FI main relay 2.

Check for the following fuses:

	No. A15 (15 A) fuse (in the under-hood fuse/relay box)
	No. B9 (20 A) fuse (in the under-dash fuse/relay box)


	Pattern 3

Check the PCS for leaks.


	Pattern 2 and 4

Go to step 10 (diagnosis by parameter (MISFIRE)).

10.

On-board snapshot check (MISFIRE):

On-board snapshot check (MISFIRE)

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

?2.

Select the MISFIRE and ENGINE SPEED in the configuration list.

Check the recorded snapshot or on-board snapshot parameters at the time of the engine stall, then compare those snapshots to the MISFIRE pattern from the charts, and determine the problem.

Pattern	Symptom (Diagnosis by parameter)	Additional remarks
Pattern 1	Engine stalls after MISFIRE counts go up	When engine stalls after MISFIRE count increases, the engine stall may be caused by misfire.
Pattern 2	Normal when engine stalls with MISFIRE count remaining constant	If the MISFIRE count remains steady when the engine stalls, the stall was not caused by 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 DTC P0300?P0306 troubleshooting.


	Pattern 2 (Reproducible failure)

Go to step 11 (diagnosis by parameter (EGR valve position sensor (EGR VLS))).


	Pattern 2 (Intermittent failure)

Go to step 12 (diagnosis by parameter (A/C CLUTCH)).

11.

On-board snapshot check (EGR valve position sensor (EGR VLS)):

On-board snapshot check (EGR valve position sensor (EGR VLS))

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

?2.

Select the EGR valve position sensor (EGR VLS), EGR L COMMAND, and ENGINE SPEED in the configuration list.

Check the recorded snapshot or on-board snapshot parameters at the time of engine stall, then compare the EGR valve position sensor (EGR VLS) pattern from the charts, 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	If the EGR valve position sensor (EGR VLS) voltage is about 1.3 V or more when the engine stalls, the EGR valve may be stuck open.
Pattern 2	EGR valve position sensor (EGR VLS) indicates the EGR is normal	The EGR valve position sensor (EGR VLS) voltage should be less than 1.3 V.

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 shut out the EGR port, and recheck. If it is OK, replace the EGR valve.


	Pattern 2

The EGR valve is OK. Go to step 12 (diagnosis by parameter (A/C CLUTCH)).

12.

On-board snapshot check (A/C CLUTCH):

On-board snapshot check (A/C CLUTCH)

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

?2.

Select the A/C CLUTCH and ENGINE SPEED in the configuration list.

Check the recorded snapshot or on-board snapshot parameters at the time of the engine stall, then compare the A/C CLUTCH pattern from the charts, and determine the problem.

Pattern	Symptom (Diagnosis by parameter)	Additional remarks
Pattern 1	Engine stalls when A/C CLUTCH is ON.	If the engine stall occurs just after the A/C compressor clutch turns on, the stall may be caused by excessive A/C compressor load.
Pattern 2	Engine stalls during A/C CLUTCH is OFF.	If the engine stall occurs just when the A/C compressor clutch is off, the A/C system is not the cause of the engine stall.

Which pattern is indicated?


	Pattern 1

Diagnostic procedure:

1.	Check for over-charge A/C refrigerant.
2.	Check for charging with the wrong refrigerant.
3.	Check for drag of the A/C compressor and A/C compressor clutch.


	Pattern 2 (A/T)

Go to step 13 (diagnosis by parameter (PNP SWITCH)).


	Pattern 2 (M/T)

Go to step 15 (fuel system troubleshooting).

13.

On-board snapshot check (PNP SWITCH):

On-board snapshot check (PNP SWITCH)

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

?2.

Select the PNP SWITCH and ENGINE SPEED in the configuration list.

Check the recorded snapshot or on-board snapshot parameters at the time of the engine stall, then compare the PNP SWITCH pattern from the charts, and determine the problem.

Pattern	Symptom (Diagnosis by parameter)	Additional remarks
Pattern 1	A/T is in-gear condition	In-gear condition when PNP SWITCH is “GEAR”. Engine stall may be caused by A/T. (Engine also is a factor)
Pattern 2	A/T is N or P condition	N or P condition when PNP SWITCH is “P-N”. The engine stall is not caused by A/T. A/T is not faulty.

Which pattern is indicated?


	Pattern 1

Go to step 14 (diagnosis by parameter (SLIP RATIO OF TORQ OR STARTCLUTCH)).


	Pattern 2

Go to step 15 (fuel system troubleshooting)

14.

On-board snapshot check (SLIP RATIO OF TORQ OR STARTCLUTCH):

On-board snapshot check (SLIP RATIO OF TORQ OR STARTCLUTCH)

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

?2.

Select the SLIP RATIO OF TORQ OR STARTCLUTCH, ENGINE SPEED, and VEHICLE SPEED in the configuration list.

Check the recorded snapshot or on-board snapshot parameters at the time of the engine stall, then compare the SLIP RATIO OF TORQ OR STARTCLUTCH pattern from the charts, and determine the problem.

Pattern	Symptom (diagnosis by parameter)	Additional remarks
Pattern 1	Engine stall caused by lock up	When engine stalls, SLIP RATIO OF TORQ OR STARTCLUTCH is near 100 % from deceleration to stopping, the engine stall is caused by lock up.
Pattern 2	Lock up normal	Lock up is normal when engine stalls with SLIP RATIO OF TORQ OR STARTCLUTCH near “0” in the middle of deceleration.

Which pattern is indicated?


	Pattern 1

Go to the automatic transmission systems symptom troubleshooting index for torque converter clutch does not disengage.


	Pattern 2

Go to step 15 (fuel system troubleshooting).

15.

Fuel pressure check:

Fuel pressure check

?1.	Do the fuel pressure test.

Is the fuel pressure OK?


	YES

Go to step 16 (ignition system troubleshooting).


	NO

Check for following parts:

	Go to the fuel pump circuit troubleshooting procedure for DTC P0627.
	Fuel pressure regulator
	Fuel filter

16.

Spark plug visual check:

Spark plug visual check

?1.	Press the engine start/stop button to select the OFF 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?


	YES (wet)

Check the following conditions. If those conditions do not apply, go to step 17.

	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 17.

17.

Determine possible failure area (ignition system, others):

Determine possible failure area (ignition system, others)

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

?2.	Press the engine start/stop button to select the OFF mode.

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

?4.	Crank the engine and watch for spark at the spark plugs.

Do the spark plugs spark?


	YES

The ignition system is OK. Select PCM reset in the PGM-FI INSPECTION MENU to cancel ALL INJECTORS with the HDS, then go to step 19 (engine compression troubleshooting).


	NO

Go to step 18.

18.

Ignition coil power circuit check:

Ignition coil power circuit check

?1.

Disconnect the following connector(s).

Ignition coil(s) 3P connector from the problem cylinder

?2.	Remove the ignition coil relay (A) from the under-hood fuse/relay box.

?3.

Check for continuity between test points 1 and 2.

Test condition	OFF mode
	Ignition coil 3P connector: disconnected
	Ignition coil relay: disconnected
Test circuit	IG (IGN COIL)/IG COIL RLY OUT
Test point 1	Ignition coil relay 4P socket No. 2
Test point 2	Ignition coil 3P connector No. 1 (RED)

Is there continuity?


	YES

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


	NO

Repair an open in the IG (IGN COIL)/IG(IGN COIL J/C)/IG COIL RLY OUT wire between the ignition coil relay and ignition coil.

19.

Engine compression check:

Engine compression check

?1.	Do an engine compression inspection.

Is the engine compression OK?


	YES

Go to step 20 (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

20.

EVAP canister purge valve check:

EVAP canister purge valve check

?1.	Press the engine start/stop button to select the OFF 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.

?4.	Start the engine.

Does the vacuum gauge indicate vacuum?


	YES

When the climate is warm, fuel vapors from the fuel tank stored in the canister enter the intake manifold, enriching the mixture (excessively rich), causing the engine to stall in some cases. If needed, replace the EVAP canister purge valve.


	NO (Reproducible failure)

Go to step 21 (fuse check).


	NO (Intermittent failure)

Go to step 22 (relay check).

21.

Fuse check:

Fuse check

?1.

Check the following fuses.

Fuse	No. A7 (15 A) to the PGM-FI subrelay
Fuse	No. A9 (15 A) to the ignition coil relay
Fuse	No. A15 (15 A) to PGM-FI main relay 1
Location	Under-hood fuse/relay box

Fuse	No. B9 (20 A) to PGM-FI main relay 2
Location	Under-dash fuse/relay box

Are the fuses OK?


	YES

The fuses are OK. Go to step 22 (relay check).


	NO

Replace the blown fuse(s).

22.

Relay check:

Relay check

?1.

Test the following relays:

NOTE: In situations where the failure is difficult to reproduce, the following relays may have an intermittent failure.

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

Are the relays OK?


	YES

Go to the diagnostic interview.


	NO

Replace any damaged relays.