NO.10 LOW IDLE/STALLS DURING DECELERATION [LF, L3]


10	LOW IDLE/STALLS DURING DECELERATION
DESCRIPTION	• Engine stops unexpectedly at beginning of deceleration or recovery from deceleration.
POSSIBLE CAUSE	• Vacuum leakage • IAC valve malfunction • Air leakage from intake-air system • Improper air/fuel mixture ratio control • Evaporative emission control system malfunction • TP sensor misadjustment • TP sensor or related circuit malfunction • MAF sensor or related circuit malfunction • Brake switch or related circuit malfunction • Neutral/clutch pedal position switch or related circuit malfunction (MTX) • TR switch or related circuit malfunction (ATX) • Improper A/C magnetic clutch operation


STEP	INSPECTION	RESULTS	ACTION
1	• Does the engine idle roughly?	Yes	Go to the symptom troubleshooting "No.8 Engine runs rough/rolling idle".
1	• Does the engine idle roughly?	No	Go to the next step.
2	Turn off the A/C switch and the fan switch. Does the A/C magnetic clutch engage?	Yes	Go to symptom troubleshooting "No.24 A/C is always on or A/C compressor runs continuously."
2		No	Go to the next step.
3	Inspect the following: • Proper routing and no damage to the vacuum lines • IAC valve is connected properly. • No air leakage from the intake-air system Are all items normal?	Yes	Go to the next step.
3		No	Service if necessary. Repeat Step 3.
4	Connect the WDS or equivalent to the DLC-2. Retrieve any continuous memory, KOEO and KOER DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC test.
4		No	No DTC is displayed: Go to the next step.
5	Does idle speed drop or stall when the IAC valve is disconnected?	Yes	Go to the next step.
5		No	Inspect the following: • Circuit from IAC valve to PCM connector terminal 4G or 4J for open or short circuit • IAC valve for sticking If normal, go to the next step.
6	Disconnect vacuum hose between the purge solenoid valve and the intake manifold from the purge solenoid valve side. Plug the open end of the vacuum hose. Drive the vehicle. Does the engine condition improve?	Yes	Inspect the evaporative emission control system.
6		No	Go to the next step.
7	Connect the WDS or equivalent to the DLC-2. Access the TP, MAF, VSS, BOO, CPP, CPP/PNP and TR PIDs. Monitor each PID while driving the vehicle. (See PCM INSPECTION [LF, L3].) Are the PIDs normal?	Yes	Intermittent concern exists. (See INTERMITTENT CONCERN TROUBLESHOOTING.)
7		No	TP PID: Inspect TP sensor. MAF PID: Inspect MAF sensor. VSS PID: Inspect VSS. BOO PID: Inspect brake switch. CPP PID: Inspect clutch pedal position switch (MTX). CPP/PNP PID: Inspect neutral switch (MTX). TR PID: Inspect TR switch (ATX) switch.
8	Verify the test results. • If normal, return to the diagnostic index to service any additional symptoms. • If the malfunction remains, replace the PCM.