No.9 Fast Idle/Runs On - Mazda 6 2002 Workshop Manual

STEP INSPECTION
13 Connect WDS or equivalent to DLC-2.
Start the engine and run it at idle.
Access O2S11 PID.
Is O2S11 PID okay?
• More than 0.45 V when accelerator pedal is
suddenly depressed: rich condition
• Less than 0.45 V during fuel cut: lean
condition
14 Disconnect vacuum hose between purge
solenoid valve and intake manifold from purge
solenoid valve side.
Plug opening end of vacuum hose. Start engine.
Does engine condition improve?
15 Remove and shake PCV valve.
Does PCV valve rattle?
16 Inspect for restriction in ehaust system.
Is there any restriction?
17 Visually inspect CMP sensor and teeth of
camshaft.
Are CMP sensor and teeth of camshaft okay?
18 Inspect engine condition while tapping EGR
valve housing.
Does engine condition improve?
19 Note
• The following test should be performed for
vehicles with variable valve timing control
system. Go to net step for vehicles witout
variable valve timing control system.
Inspect variable valve timing control system
operation.
(See F–239 Variable Valve Timing Control
System Operation Inspection.)
Does variable valve timing control system work
properly?
20 Is engine compression correct?
21 Verify test results.
• If okay, return to diagnostic inde to service any additional symptoms.
• If malfunction remains, replace PCM.
End Of Sie

NO.9 FAST IDLE/RUNS ON

9 FAST IDLE/RUNS ON
• Engine speed continues at fast idle after warm-up.
DESCRIPTION
• Engine runs after ignition switch is turned off.
• ECT sensor malfunction
• Air leakage from intake-air system
• Throttle body malfunction
POSSIBLE CAUSE
• Accelerator cable free play misadjustment
• Cruise control cable misadjustment
• Improper load signal input
Diagnostic procedure
STEP INSPECTION
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—
234° ° ° ° F}?
TROUBLESHOOTING
RESULTS
Yes Go to net step.
No Inspect and repair or replace faulty HO2S, harness,
connector or terminal, then go to net step.
Yes Inspect if purge solenoid valve sticks open
mechanically.
Inspect EVAP control system.
No Go to net step.
Yes Go to net step.
No Replace PCV valve.
Yes Inspect ehaust system.
No Go to net step.
Yes Go to net step.
No Replace malfunctioning parts.
Yes Replace EGR valve.
No Go to net step.
Yes Go to net step.
No Repair or replace malfunctioning parts.
Yes Inspect valve timing.
No Inspect for causes.
RESULTS
Yes Go to net step.
No ECT PID is higher than 112° ° ° ° C {234° ° ° ° 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".
ACTION
A6E398018881W11
ACTION
F–201
F