NO.9 LOW IDLE/STALLS DURING DECELERATION [G6]

id010395850200

9

LOW IDLE/STALLS DURING DECELERATION

DESCRIPTION

•  The engine stops unexpectedly at the beginning of deceleration or recovery from deceleration.

POSSIBLE CAUSE

•  Vacuum leakage

•  IAC valve malfunction

•  Air leakage from intake-air system

•  MAF sensor or related circuit malfunction

•  TP sensor or related circuit malfunction

•  Brake switch or related circuit malfunction

•  Neutral/clutch pedal position switch or related circuit malfunction

9	LOW IDLE/STALLS DURING DECELERATION
DESCRIPTION	• The engine stops unexpectedly at the beginning of deceleration or recovery from deceleration.
POSSIBLE CAUSE	• Vacuum leakage • IAC valve malfunction • Air leakage from intake-air system • MAF sensor or related circuit malfunction • TP sensor or related circuit malfunction • Brake switch or related circuit malfunction • Neutral/clutch pedal position switch or related circuit malfunction

Diagnostic procedure

STEP	INSPECTION	RESULTS	ACTION
1	Does the engine idle rough?	Yes	Go to symptom troubleshooting “No.7 Engine runs rough/rolling idle”. (See NO.7 ENGINE RUNS ROUGH/ROLLING IDLE [G6].)
1	Does the engine idle rough?	No	Go to the next step.
2	Verify following: • Proper routing and no damage of vacuum lines • IAC valve is connected properly. • No air leakage from intake-air system Are all items normal?	Yes	Go to the next step.
2		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. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate the DTC inspection. (See DTC TABLE [G6].)
3		No	No DTC is displayed: Go to the next step.
4	Does the idle speed drop or stall when disconnecting the IAC valve?	Yes	Go to the next step.
4		No	Inspect the following: • Circuit from IAC valve to PCM terminal 2W for open and short • IAC valve for sticking If normal, go to the next step.
5	Disconnect the vacuum hose between the purge solenoid valve and the dynamic chamber from the purge solenoid valve side. Plug the opening end of vacuum hose. Drive the vehicle. Does the engine condition improve?	Yes	Inspect evaporative emission control system.
5		No	Go to the next step.
6	Connect the M-MDS to DLC-2. Access TP, MAF, VSS, BOO and CPP/PNP PIDs. Monitor each PID while driving the vehicle. • TP PID • MAF PID • VSS PID • BOO PID • CPP/PNP PID Are PIDs normal? (See PCM INSPECTION [G6].)	Yes	Go to symptom troubleshooting “No.26 Intermittent Concerns”. (See NO.26 INTERMITTENT CONCERNS [G6].)
6		No	TP PID • Inspect TP sensor. MAF PID: • Inspect the MAF sensor. VSS PID: • Inspect the VSS. BOO PID • Inspect brake switch. CPP/PNP PID • Inspect neutral switch and clutch switch.
7	• Verify test results. ― If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [G6].) ― 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. (See PCM REMOVAL/INSTALLATION [G6].)