NO.9 FAST IDLE/RUNS ON [MZR 2.0 DISI i-stop]

id0103d3801500

9

FAST IDLE/RUNS ON
DESCRIPTION
•  Engine speed continues at fast idle after warm-up.
•  Engine runs after ignition switch is turned off.
POSSIBLE CAUSE
•  Cooling system malfunction
•  PCM DTC is stored.
•  Air leakage from intake-air system
•  Improper operation of drive-by-wire control system
•  Throttle body malfunction
•  Erratic signal to PCM
―  APP sensor or related circuit malfunction
―  ECT sensor or related circuit malfunction
―  Improper A/C request signal or related circuit malfunction
―  CPP switch or related circuit malfunction (MTX)
―  Neutral switch or related circuit malfunction (MTX)
―  TR switch or related circuit malfunction (ATX)
•  Spill valve control solenoid valve (built-in high pressure fuel pump) malfunction
•  Fuel injector malfunction
•  Improper operation of cruise control system
•  Injector driver (built-in PCM) malfunction
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 2.0 DISI i-stop].) (See AFTER SERVICE PRECAUTION [MZR 2.0 DISI i-stop].)
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.

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION
1
Access the ECT PID using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 2.0 DISI i-stop].)
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".
ECT PID is less than 82 °C {180 °F}:
•  Perform the symptom troubleshooting "NO.18 COOLING SYSTEM CONCERNS-RUNS COLD".
2
Connect the M-MDS to the DLC-2.
Switch the ignition to ON (engine off).
Retrieve any DTCs using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 2.0 DISI i-stop].)
Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 2.0 DISI i-stop].)
No
Go to the next step.
3
Inspect for leakage in 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 2.0 DISI i-stop].)
Does the drive-by-wire 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 2.0 DISI i-stop].)
•  AC_REQ
•  APP
•  ECT
•  CPP (MTX)
•  CPP/PNP (MTX)
•  TR (ATX)
Do the PIDs indicate the correct values under the trouble condition?
(See PCM INSPECTION [MZR 2.0 DISI i-stop].)
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts according to the inspection results.
•  If the malfunction remains:
―  Perform the “INTERMITTENT CONCERN TROUBLESHOOTING”.
6
Inspect the high pressure fuel pump.
(See HIGH PRESSURE FUEL PUMP INSPECTION [MZR 2.0 DISI i-stop].)
Is there any malfunction?
Yes
Replace the high pressure fuel pump.
(See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [MZR 2.0 DISI i-stop].)
No
Go to the next step.
7
Perform the Fuel Injector Operation Inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.0 DISI i-stop].)
Do the fuel injectors operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts according to the inspection results.
8
Inspect the operation of cruise control system.
Does the cruise control system work properly?
Yes
Injector driver is malfunction.
•  Replace the PCM.
If the problem remains, overhaul the engine.
No
Repair or replace the malfunctioning parts according to the inspection results.
9
Verify the test results.
•  If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.0 DISI i-stop].)
•  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, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 2.0 DISI i-stop].)