NO.10 LOW IDLE/STALLS DURING DECELERATION [ZY]

id0103c0801600

10

LOW IDLE/STALLS DURING DECELERATION
DESCRIPTION
•  The engine stops unexpectedly at the beginning of deceleration or recovery from deceleration.
POSSIBLE CAUSE
•  Vacuum leakage
•  Improper operation of electronic throttle control system
•  Air leakage from intake-air system
•  Improper air/fuel mixture ratio control
•  Evaporative emission control system malfunction
•  Accelerator pedal position sensor or related circuit malfunction
•  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

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION
1
Does the engine idle rough?
Yes
Go to symptom troubleshooting "No.8 Engine runs rough/rolling idle".
(See NO.8 ENGINE RUNS ROUGH/ROLLING IDLE [ZY].)
No
Go to the next step.
2
Turn off the A/C switch and 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.“
(See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [ZY].)
No
Go to the next step.
3
Verify the following:
•  Proper routing and no damage of vacuum lines
•  Drive-by-wire control operates improperly.
•  No air leakage from intake-air system
Are all items normal?
Yes
Go to the next step.
No
Service if necessary.
Repeat Step 3.
4
Connect WDS or equivalent to DLC-2.
Retrieve any continuous memory, KOEO and KOER DTCs using WDS or equivalent.
Are there any DTCs displayed?
Yes
DTC is displayed:
Go to the appropriate DTC inspection.
(See DTC TABLE [ZY].)
No
No DTC is displayed:
Go to the next step.
5
Perform the electronic throttle control inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [ZY].)
Does the electronic throttle operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to electronic throttle control inspection results.
6
Disconnect the vacuum hose between the purge solenoid valve and the intake manifold from the purge solenoid valve side.
Plug the opening end of vacuum hose.
Drive the vehicle.
Does the engine condition improve?
Yes
Inspect EVAP control system.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [ZY].)
No
Go to the next step.
7
Connect the WDS or equivalent to DLC-2.
Access APP, TP, MAF, VSS, BOO, CPP, CPP/PNP and TR PIDs.
Monitor each PID while driving the vehicle.
(See PCM INSPECTION [ZY].)
Are PIDs normal?
Yes
Intermittent concern exists.
(See INTERMITTENT CONCERN TROUBLESHOOTING [ZY].)
No
APP PID:
Inspect the accelerator pedal position sensor.
(See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [ZY].)
TP PID:
Inspect the TP sensor.
(See THROTTLE POSITION (TP) SENSOR INSPECTION [ZY].)
MAF PID:
Inspect the MAF sensor.
(See MASS AIR FLOW (MAF) SENSOR INSPECTION [ZY].)
VSS PID:
Inspect the VSS.
(See DTC TABLE [ZY].)
BOO PID:
Inspect the brake switch.
(See BRAKE SWITCH INSPECTION.)
CPP PID:
Inspect the clutch pedal position switch (MTX).
(See CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [ZY].)
CPP/PNP PID:
Inspect the neutral switch (MTX).
(See NEUTRAL SWITCH INSPECTION [ZY].)
TR PID:
Inspect the TR switch (ATX).
(See TRANSAXLE RANGE (TR) SWITCH INSPECTION [FN4A-EL].)
8
Verify test results.
•  If normal, return to diagnostic index to service any additional symptoms.
•  If malfunction remains, inspect related Service information perform repair or diagnosis.
―  If vehicle repaired, troubleshooting completed.
―  If vehicle not repaired or additional diagnostic information not available, replace the PCM.