NO.9 FAST IDLE/RUNS ON [MZR-CD (RF Turbo)]


BME010300000W44

9

RUNS IDLE/RUNS ON

DESCRIPTION

• Engine speed continues at fast idle after warm-up.
• Engine runs after engine key turned off.

POSSIBLE CAUSE

• ECT sensor or related circuit malfunction
• Incorrect adjustment accelerator position sensor and/or idle switch
• Suction control valve (built-in supply pump)
• Fuel injector malfunction
• IDM or related circuit 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 REPAIR PROCEDURE" and "AFTER REPAIR PROCEDURE" described in this manual.

Diagnostic Procedure

STEP

INSPECTION

RESULTS

ACTION

1
Connect WDS or equivalent to DLC-2.
Access ECT PID.
Start and warm-up engine to normal operating temperature.
Is ECT PID reading between 82-112 °C {180-233 °F}?
Yes
Go to next step.
No

ECT PID is higher than 112 °C{233 °F}:

Go to symptom troubleshooting "NO.17 COOLING SYSTEM CONCERNS-OVERHEATING".

ECT PID is less than 82 °C{180 °F}:

Go to symptom troubleshooting "NO.18 COOLING SYSTEM CONCERNS-RUNS COLD".
2
Perform self-test function using WDS or equivalent.
Turn engine switch to ON.
Retrieve any DTC.
Is DTC displayed?
Yes

DTC is displayed:

Go to appropriate DTC test.

Communication error message is displayed:

Inspect for following:
• Open circuit between PCM control relay and PCM terminal 53 or 79
• Open circuit PCM control relay and PCM terminal 69
• PCM control relay stuck open
• Open or poor GND circuit (PCM terminal 65, 85, 103 or 104)
• Poor connection vehicle body GND
No

No DTC is displayed:

Go to next step.
3
Inspect suction control valve.
Is suction control valve okay?
Yes
Go to next step.
No
Repair supply pump.
4
Inspect fuel injector.
Is fuel injector okay?
Yes
Verify accelerator position sensor and idle switch.
No
Replace fuel injector.
5
Verify test results.
• If okay, return to diagnostic index to service any additional symptoms.
• If malfunction remains, replace PCM. (See PCM REMOVAL/INSTALLATION [MZR-CD (RF Turbo)].)