NO.9 FAST IDLE/RUNS ON [MZR 2.3 DISI Turbo]

9	FAST IDLE/RUNS ON
DESCRIPTION	• Engine speed continues at fast idle after warm-up. • Engine runs after the ignition is switched off.
POSSIBLE CAUSE	• ECT sensor or related circuit malfunction • Spill valve control solenoid valve malfunction (built-in high pressure fuel pump) • Fuel injector malfunction • Air leakage from intake-air system • Throttle body malfunction • APP sensor or related circuit malfunction • Improper operation of cruise control system • Improper load signal input • Improper operation of electric throttle control system 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 [MZR 2.3 DISI Turbo].) (See AFTER SERVICE PRECAUTION [MZR 2.3 DISI 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.

FAST IDLE/RUNS ON

DESCRIPTION

• Engine speed continues at fast idle after warm-up.

• Engine runs after the ignition is switched off.

POSSIBLE CAUSE

• ECT sensor or related circuit malfunction

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

• Fuel injector malfunction

• Air leakage from intake-air system

• Throttle body malfunction

• APP sensor or related circuit malfunction

• Improper operation of cruise control system

• Improper load signal input

• Improper operation of electric throttle control system

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 [MZR 2.3 DISI Turbo].) (See AFTER SERVICE PRECAUTION [MZR 2.3 DISI 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	Access the ECT PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].) Start the engine and warm it up completely. Is the ECT PID value between 82—112 °C {180—234 °F}?	Yes	Go to the next step.
No	ECT PID value is higher than 112 °C {234 °F}: • Perform the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”. (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [MZR 2.3 DISI Turbo].) ECT PID value is less than 82 °C {180 °F}: • Perform the symptom troubleshooting “NO.18 COOLING SYSTEM CONCERNS-RUNS COLD”. (See NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [MZR 2.3 DISI Turbo].)
2	Switch the ignition to ON. Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZR 2.3 DISI Turbo].)
No	Go to the next step.
3	Inspect for leakage in the intake-air system. Is there any leakage?	Yes	Repair or replace the malfunctioning parts according to the inspection results.
No	Go to the next step.
4	Perform the TP sweep inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.3 DISI Turbo].) Does the electronic throttle control system work properly?	Yes	Visually inspect the throttle body (damage/scratching). • If normal: ― Go to the next step. • If not: ― Repair or replace the malfunctioning parts according to the inspection results.
No	Repair or replace the malfunctioning parts according to the inspection results.
5	Access the following PIDs using the M-MDS: (See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].) • AC_REQ • APP1 • APP2 • ECT Do the PID values indicate the correct values under the trouble condition? (See PCM INSPECTION [MZR 2.3 DISI Turbo].)	Yes	Go to the next step.
No	Inspect the suspected parts and related wiring harness. • If normal: ― Perform the “INTERMITTENT CONCERN TROUBLESHOOTING. (See INTERMITTENT CONCERN TROUBLESHOOTING [MZR 2.3 DISI Turbo].) • If not: ― Repair or replace the malfunctioning parts according to the inspection results.
6	Inspect the high pressure fuel pump. (See HIGH PRESSURE FUEL PUMP INSPECTION [MZR 2.3 DISI Turbo].) Is there any malfunction?	Yes	Replace the high pressure fuel pump. (See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [MZR 2.3 DISI Turbo].)
No	Go to the next step.
7	Perform the Fuel Injector Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.3 DISI Turbo].) Do the fuel injectors operate normally?	Yes	Go to the next step.
No	Repair or replace the malfunctioning parts according to the inspection results.
8	Inspect the operation of the cruise control system. Does the cruise control system work properly?	Yes	Replace the PCM (injector driver circuit malfunction). (See PCM REMOVAL/INSTALLATION [MZR 2.3 DISI Turbo].)
No	Repair or replace the malfunctioning parts according to the inspection results.
9	Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. • If a malfunction remains, inspect the related Service 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

Access the ECT PID using the M-MDS.

(See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].)

Start the engine and warm it up completely.

Is the ECT PID value between 82—112 °C {180—234 °F}?

Yes

Go to the next step.

ECT PID value is higher than 112 °C {234 °F}:

• Perform the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”.

(See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [MZR 2.3 DISI Turbo].)

ECT PID value is less than 82 °C {180 °F}:

• Perform the symptom troubleshooting “NO.18 COOLING SYSTEM CONCERNS-RUNS COLD”.

(See NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [MZR 2.3 DISI Turbo].)

Switch the ignition to ON.

Retrieve any DTCs using the M-MDS.

(See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].)

Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [MZR 2.3 DISI Turbo].)

Go to the next step.

Inspect for leakage in the intake-air system.

Is there any leakage?

Yes

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

Go to the next step.

Perform the TP sweep inspection.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.3 DISI Turbo].)

Does the electronic throttle control system work properly?

Yes

Visually inspect the throttle body (damage/scratching).

• If normal:

― Go to the next step.

• If not:

― Repair or replace the malfunctioning parts according to the inspection results.

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

Access the following PIDs using the M-MDS:

(See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].)

• AC_REQ

• APP1

• APP2

• ECT

Do the PID values indicate the correct values under the trouble condition?

(See PCM INSPECTION [MZR 2.3 DISI Turbo].)

Yes

Go to the next step.

Inspect the suspected parts and related wiring harness.

• If normal:

― Perform the “INTERMITTENT CONCERN TROUBLESHOOTING.

(See INTERMITTENT CONCERN TROUBLESHOOTING [MZR 2.3 DISI Turbo].)

• If not:

― Repair or replace the malfunctioning parts according to the inspection results.

Inspect the high pressure fuel pump.

(See HIGH PRESSURE FUEL PUMP INSPECTION [MZR 2.3 DISI Turbo].)

Is there any malfunction?

Yes

Replace the high pressure fuel pump.

(See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [MZR 2.3 DISI Turbo].)

Go to the next step.

Perform the Fuel Injector Operation Inspection.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.3 DISI Turbo].)

Do the fuel injectors operate normally?

Yes

Go to the next step.

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

Inspect the operation of the cruise control system.

Does the cruise control system work properly?

Yes

Replace the PCM (injector driver circuit malfunction).

(See PCM REMOVAL/INSTALLATION [MZR 2.3 DISI Turbo].)

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

Verify test results.

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

• If a malfunction remains, inspect the related Service 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.