NO.10 LOW IDLE/STALLS DURING DECELERATION[AJ (3.0L Duratec)]

id0103a7801600

10
Low idle/stalls during deceleration
DESCRIPTION
•  Engine stops unexpectedly at beginning of deceleration or recovery from deceleration.
POSSIBLE CAUSE
•  Vacuum leakage
•  IAC solenoid valve malfunction
•  Air leakage from intake-air system
•  TP sensor or related circuit malfunction
•  MAF sensor or related circuit malfunction
•  Brake switch or related circuit malfunction

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION
1
•  Does the engine idle rough?
Yes
Go to symptom troubleshooting “No.8 Engine runs rough/rolling idle”.
No
Go to the next step.
2
•  Verify the following:
―  Proper routing and no damage of vacuum lines
―  IAC solenoid valve properly connected
―  No air leakage from intake-air system
•  Are all items normal?
Yes
Go to the next step.
No
Service if necessary.
Repeat Step 2.
3
•  Connect the M-MDS to the DLC–2.
•  Turn the ignition switch to the ON position (Engine off).
•  Retrieve any DTCs.
•  Is “PASSED” displayed?
Yes
No DTC is displayed:
•  Go to the next step.
No
DTC is displayed:
•  Go to the appropriate DTC test.
4
•  Does idle speed drop or stall when disconnecting IAC solenoid valve?
Yes
Go to the next step.
No
Inspect the following:
•  Circuit from IAC solenoid valve to PCM connector terminal 83 for open or short
•  Circuit from IAC solenoid valve to main relay terminal B for open or short
•  IAC solenoid valve for sticking
―  If normal, go to the next step.
5
•  Disconnect the vacuum hose between purge solenoid valve and intake manifold from purge solenoid valve side.
•  Plug opening end of vacuum hose.
•  Drive vehicle.
•  Does the engine condition improve?
Yes
Inspect the EVAP control system.
No
Go to the next step.
6
•  Connect the M-MDS to the DLC–2.
•  Access the TP, MAF and VSS PIDs.
•  Monitor each PID while driving vehicle.
•  Are PIDs normal?
Yes
Intermittent concern exists.
(See INTERMITTENT CONCERN TROUBLESHOOTING[AJ (3.0L Duratec)].)
No
TP PID:
•  Inspect the TP sensor.
MAF PID:
•  Inspect the MAF sensor.
VSS PID:
•  Inspect the VSS.
7
•  Verify the test results.
―  If normal, return to the diagnostic index to service any additional symptoms.
―  If malfunction remains, inspect related Service Information and perform repair or diagnosis.
•  If vehicle is repaired, troubleshooting completed.
•  If vehicle is not repaired or additional diagnostic information is not available, replace the PCM.