NO.8 ENGINE RUNS ROUGH/ROLLING IDLE[L3 Turbo]

8	ENGINE RUNS ROUGH/ROLLING IDLE
DESCRIPTION	• Engine speed fluctuates between the specified idle speed and lower speed and, engine shakes excessively. • Idle speed is too slow and the engine shakes excessively.
POSSIBLE CAUSE	• Air leakage from intake-air system • A/C system improper operation • Erratic signal to ignition coil • Spark plug malfunction • Purge solenoid valve malfunction • Improper operation of electronic throttle control system • EGR valve malfunction • Low engine compression or excessive unbalance for each cylinder • Improper valve timing • Improper variable valve timing control system • Poor fuel quality • PCV valve malfunction • Intake-air system restriction • Exhaust system or three-way catalytic converter (TWC) restriction or clogging • Disconnected electrical connectors • Inadequate fuel pressure (high or low pressure side) • Fuel pressure sensor or related circuit malfunction • Spill valve control solenoid valve malfunction (built-in high pressure fuel pump) • Relief valve malfunction (built-in delivery pipe) • Fuel pump (low-side) body mechanical malfunction • Fuel filter restriction or clogging • Fuel leakage • Incorrect fuel injection timing • Unbalanced fuel injection amount for each cylinder • High pressure fuel pump malfunction • Fuel injector malfunction • Erratic signal from CKP sensor • Erratic or no signal from CMP sensor • ECT sensor or related circuit malfunction • Manifold absolute pressure (MAP) sensor or related circuit malfunction • Accelerator position sensor or related circuit malfunction • MAF sensor malfunction • Incorrect or no load signal input • Engine overheating • Vacuum leakage Warning The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services: • Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel. • Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete "BEFORE SERVICE PRECAUTION" and "AFTER SERVICE PRECAUTION" described in this manual. (See BEFORE SERVICE PRECAUTION[L3 Turbo].) (See AFTER SERVICE PRECAUTION[L3 Turbo].) Caution • Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.

ENGINE RUNS ROUGH/ROLLING IDLE

DESCRIPTION

• Engine speed fluctuates between the specified idle speed and lower speed and, engine shakes excessively.

• Idle speed is too slow and the engine shakes excessively.

POSSIBLE CAUSE

• Air leakage from intake-air system

• A/C system improper operation

• Erratic signal to ignition coil

• Spark plug malfunction

• Purge solenoid valve malfunction

• Improper operation of electronic throttle control system

• EGR valve malfunction

• Low engine compression or excessive unbalance for each cylinder

• Improper valve timing

• Improper variable valve timing control system

• Poor fuel quality

• PCV valve malfunction

• Intake-air system restriction

• Exhaust system or three-way catalytic converter (TWC) restriction or clogging

• Disconnected electrical connectors

• Inadequate fuel pressure (high or low pressure side)

• Fuel pressure sensor or related circuit malfunction

• Spill valve control solenoid valve malfunction (built-in high pressure fuel pump)

• Relief valve malfunction (built-in delivery pipe)

• Fuel pump (low-side) body mechanical malfunction

• Fuel filter restriction or clogging

• Fuel leakage

• Incorrect fuel injection timing

• Unbalanced fuel injection amount for each cylinder

• High pressure fuel pump malfunction

• Fuel injector malfunction

• Erratic signal from CKP sensor

• Erratic or no signal from CMP sensor

• ECT sensor or related circuit malfunction

• Manifold absolute pressure (MAP) sensor or related circuit malfunction

• Accelerator position sensor or related circuit malfunction

• MAF sensor malfunction

• Incorrect or no load signal input

• Engine overheating

• Vacuum leakage

Warning

The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services:

• Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.

• Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete "BEFORE SERVICE PRECAUTION" and "AFTER SERVICE PRECAUTION" described in this manual.

(See BEFORE SERVICE PRECAUTION[L3 Turbo].)

(See AFTER SERVICE PRECAUTION[L3 Turbo].)

Caution

• Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.

STEP	INSPECTION	RESULTS	ACTION
1	Inspect for the following: • Fuel quality (proper octane, contamination, winter/summer blend) • Intake-air system restriction or leakage • Electrical connectors connection • Fuel leakage in fuel system • Vacuum leakage Are all items normal?	Yes	Go to the next step.
No	Service if necessary. Repeat Step 1.
2	Perform the self-test function using the M-MDS. Turn the ignition switch to the ON position. Retrieve any DTCs. Is a DTC displayed?	Yes	DTC is displayed: Go to the appropriate DTC test. (See DTC TABLE[L3 Turbo].)
No	No DTC is displayed: Go to the next step.
3	Access the ECT PID. Verify that the ECT PID is less than 116°C {241°F} during driving. Is the ECT PID less than specified?	Yes	Go to the next step.
No	The cause of this concern could be from the cooling system overheating. Perform the symptom troubleshooting "NO.17 COOLING SYSTEM CONCERNS - OVERHEATING." (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING[L3 Turbo].)
4	Perform the A/C Cut-off Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION[L3 Turbo].) Does the A/C Cut-off Operation work properly?	Yes	Go to the next step.
No	Repair or replace the malfunctioning parts according to inspection results.
5	Perform the EGR system operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION[L3 Turbo].) Does the EGR system operate properly?	Yes	Go to the next step.
No	Inspect or replace the malfunctioning parts, according to the inspection results.
6	Perform the TP sweep inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION[L3 Turbo].) Does the electronic throttle control system work properly?	Yes	Visually inspect the throttle body (damaged/scratching.) If normal, go to the next step.
No	Inspect or replace the malfunctioning parts, according the to inspection results.
7	Perform the Purge Control System Operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION[L3 Turbo].) Does the purge solenoid valve work properly?	Yes	Go to the next step.
No	Inspect or replace the malfunctioning parts, according to the inspection results.
8	Perform the Variable Valve Timing Control System Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION[L3 Turbo].) Does the variable valve timing control system work properly?	Yes	Go to the next step.
No	Inspect or replace the malfunctioning parts, according to the inspection results.
9	Inspect CMP and CKP sensor for the following; • Installation condition (See CAMSHAFT POSITION (CMP) SENSOR REMOVAL/INSTALLATION[L3 Turbo].) (See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION[L3 Turbo].) • Damaged trigger wheel and camshaft • Open or short circuit in the wiring harnesses. Is there any malfunction detected?	Yes	Repair or replace the malfunctioning part according to the inspection results.
No	Go to the next step.
10	Connect the M-MDS to the DLC-2. Access and monitor following PIDs using the data monitor function. • ACSW • APP • ECT • MAF • MAP • CPP (PCM terminal 1D) • PNP (PCM terminal 1S) • PSP (PCM terminal 2T) Do the PIDs indicate the correct values under trouble condition? (See PCM INSPECTION[L3 Turbo].)	Yes	Go to the next step.
No	Inspect and repair or replace suspected parts and the related harnesses. If the malfunction remains, perform the intermittent concern troubleshooting procedure. (See INTERMITTENT CONCERN TROUBLESHOOTING[L3 Turbo].)
11	Inspect for restriction in the exhaust system and three-way catalytic converter (TWC). Is there any restriction?	Yes	Replace the malfunctioning part.
No	Go to the next step.
12	Remove and shake the PCV valve. Does the PCV valve rattle?	Yes	Go to the next step.
No	Replace the PCV valve.
13	Perform the spark test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION[L3 Turbo].) Is a strong blue spark visible at each cylinder?	Yes	Go to the next step.
No	Inspect or replace the malfunctioning parts, according to the inspection results.
14	Access and monitor the FUEL_PRES PID. Is the FUEL_PRES PID value within the specification? (See PCM INSPECTION[L3 Turbo].)	Yes	Go to Step 18.
No	Go to the next step.
15	Is the vehicle accelerate performance normally?	Yes	Go to the next step.
No	Go to Step 17.
16	Inspect the fuel pressure sensor. (See FUEL PRESSURE SENSOR INSPECTION[L3 Turbo].) Is the fuel pressure sensor normal?	Yes	Go to Step 18.
No	Replace the delivery pipe.
17	Replace the high pressure fuel pump. Monitor FUEL_PRES PID. Is the FUEL_PRES PID value within the specified? (See PCM INSPECTION[L3 Turbo].)	Yes	Troubleshooting is completed. Go to Step 21.
No	Go to the next step.
18	Connect the fuel pressure gauge between the fuel pump and the high pressure fuel pump. Measure the fuel pressure line of the low pressure side. (See FUEL LINE PRESSURE INSPECTION[L3 Turbo].) Is the fuel pressure within the specification?	Yes	Go to the next step.
No	Inspect for the following: • Fuel line restriction • Fuel filter clogging If normal replace the fuel pump.
19	Inspect fuel injector for each cylinder. (See FUEL INJECTOR INSPECTION[L3 Turbo].) Are the fuel injectors normal?	Yes	Go to the next step.
No	Replace the suspected fuel injector. (See FUEL INJECTOR REMOVAL/INSTALLATION[L3 Turbo].)
20	Measure the compression pressure for each cylinder. (See COMPRESSION INSPECTION[L3 Turbo].) Are compression pressures within the specification?	Yes	Replace the injector driver module. If the problem remains, overhaul the engine.
No	Inspect for the following: • Damaged valve seat • Worn valve stem and valve guide • Worn or stuck piston ring • Worn piston, piston ring or cylinder • Improper valve timing Service if necessary.
21	Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. • If a malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform the repair or diagnosis. ― If the vehicle is repaired, troubleshooting is completed. ― If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.

STEP

INSPECTION

RESULTS

ACTION

Inspect for the following:

• Fuel quality (proper octane, contamination, winter/summer blend)

• Intake-air system restriction or leakage

• Electrical connectors connection

• Fuel leakage in fuel system

• Vacuum leakage

Are all items normal?

Yes

Go to the next step.

Service if necessary.

Repeat Step 1.

Perform the self-test function using the M-MDS.

Turn the ignition switch to the ON position.

Retrieve any DTCs.

Is a DTC displayed?

Yes

DTC is displayed:

Go to the appropriate DTC test.

(See DTC TABLE[L3 Turbo].)

No DTC is displayed:

Go to the next step.

Access the ECT PID.

Verify that the ECT PID is less than 116°C {241°F} during driving.

Is the ECT PID less than specified?

Yes

Go to the next step.

The cause of this concern could be from the cooling system overheating.

Perform the symptom troubleshooting "NO.17 COOLING SYSTEM CONCERNS - OVERHEATING."

(See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING[L3 Turbo].)

Perform the A/C Cut-off Operation Inspection.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION[L3 Turbo].)

Does the A/C Cut-off Operation work properly?

Yes

Go to the next step.

Repair or replace the malfunctioning parts according to inspection results.

Perform the EGR system operation inspection.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION[L3 Turbo].)

Does the EGR system operate properly?

Yes

Go to the next step.

Inspect or replace the malfunctioning parts, according to the inspection results.

Perform the TP sweep inspection.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION[L3 Turbo].)

Does the electronic throttle control system work properly?

Yes

Visually inspect the throttle body (damaged/scratching.) If normal, go to the next step.

Inspect or replace the malfunctioning parts, according the to inspection results.

Perform the Purge Control System Operation inspection.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION[L3 Turbo].)

Does the purge solenoid valve work properly?

Yes

Go to the next step.

Inspect or replace the malfunctioning parts, according to the inspection results.

Perform the Variable Valve Timing Control System Operation Inspection.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION[L3 Turbo].)

Does the variable valve timing control system work properly?

Yes

Go to the next step.

Inspect or replace the malfunctioning parts, according to the inspection results.

Inspect CMP and CKP sensor for the following;

• Installation condition

(See CAMSHAFT POSITION (CMP) SENSOR REMOVAL/INSTALLATION[L3 Turbo].)

(See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION[L3 Turbo].)

• Damaged trigger wheel and camshaft

• Open or short circuit in the wiring harnesses. Is there any malfunction detected?

Yes

Repair or replace the malfunctioning part according to the inspection results.

Go to the next step.

Connect the M-MDS to the DLC-2.

Access and monitor following PIDs using the data monitor function.

• ACSW

• APP

• ECT

• MAF

• MAP

• CPP (PCM terminal 1D)

• PNP (PCM terminal 1S)

• PSP (PCM terminal 2T)

Do the PIDs indicate the correct values under trouble condition?

(See PCM INSPECTION[L3 Turbo].)

Yes

Go to the next step.

Inspect and repair or replace suspected parts and the related harnesses.

If the malfunction remains, perform the intermittent concern troubleshooting procedure.

(See INTERMITTENT CONCERN TROUBLESHOOTING[L3 Turbo].)

Inspect for restriction in the exhaust system and three-way catalytic converter (TWC).

Is there any restriction?

Yes

Replace the malfunctioning part.

Go to the next step.

Remove and shake the PCV valve.

Does the PCV valve rattle?

Yes

Go to the next step.

Replace the PCV valve.

Perform the spark test.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION[L3 Turbo].)

Is a strong blue spark visible at each cylinder?

Yes

Go to the next step.

Inspect or replace the malfunctioning parts, according to the inspection results.

Access and monitor the FUEL_PRES PID.

Is the FUEL_PRES PID value within the specification?

(See PCM INSPECTION[L3 Turbo].)

Yes

Go to Step 18.

Go to the next step.

Is the vehicle accelerate performance normally?

Yes

Go to the next step.

Go to Step 17.

Inspect the fuel pressure sensor.

(See FUEL PRESSURE SENSOR INSPECTION[L3 Turbo].)

Is the fuel pressure sensor normal?

Yes

Go to Step 18.

Replace the delivery pipe.

Replace the high pressure fuel pump.

Monitor FUEL_PRES PID.

Is the FUEL_PRES PID value within the specified?

(See PCM INSPECTION[L3 Turbo].)

Yes

Troubleshooting is completed.

Go to Step 21.

Go to the next step.

Connect the fuel pressure gauge between the fuel pump and the high pressure fuel pump.

Measure the fuel pressure line of the low pressure side.

(See FUEL LINE PRESSURE INSPECTION[L3 Turbo].)

Is the fuel pressure within the specification?

Yes

Go to the next step.

Inspect for the following:

• Fuel line restriction

• Fuel filter clogging

If normal replace the fuel pump.

Inspect fuel injector for each cylinder.

(See FUEL INJECTOR INSPECTION[L3 Turbo].)

Are the fuel injectors normal?

Yes

Go to the next step.

Replace the suspected fuel injector.

(See FUEL INJECTOR REMOVAL/INSTALLATION[L3 Turbo].)

Measure the compression pressure for each cylinder.

(See COMPRESSION INSPECTION[L3 Turbo].)

Are compression pressures within the specification?

Yes

Replace the injector driver module.

If the problem remains, overhaul the engine.

Inspect for the following:

• Damaged valve seat

• Worn valve stem and valve guide

• Worn or stuck piston ring

• Worn piston, piston ring or cylinder

• Improper valve timing

Service if necessary.

Verify test results.

• If normal, return to the diagnostic index to service any additional symptoms.

• If a malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform the repair or diagnosis.

― If the vehicle is repaired, troubleshooting is completed.

― If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.