NO.10 LOW IDLE/STALLS DURING DECELERATION [MZR 1.3, MZR 1.5]

id0103d7801600

10

LOW IDLE/STALLS DURING DECELERATION
DESCRIPTION
•  The engine stops unexpectedly at beginning of deceleration or recovery from deceleration.
POSSIBLE CAUSE
•  Improper operation of A/C magnetic clutch
•  Vacuum leakage
•  Air leakage from intake-air system
•  Continuous memory DTC is stored
•  Improper operation of drive-by-wire control system
•  EVAP control system malfunction
•  Air leakage from intake-air system
•  Erratic signal to PCM
―  APP sensor or related wiring harness malfunction
―  TP sensor or related wiring harness malfunction
―  MAF sensor or related wiring harness malfunction
―  VSS or related wiring harness malfunction (ATX)
―  Brake switch or related wiring harness malfunction
―  CPP switch or related wiring harness malfunction (MTX)
―  Neutral switch or related wiring harness malfunction (MTX)
―  TR switch or related wiring harness malfunction (ATX, CVT)
•  Improper load signal input
―  Refrigerant pressure switch malfunction
―  Evaporator temperature sensor malfunction
―  Climate control unit malfunction
•  A/C switch or fan switch malfunction
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION
1
VERIFY IF MALFUNCTION INCLUDES ROUGH IDLING
•  Does the engine idle roughly?
Yes
Go to the symptom troubleshooting “NO.8 ENGINE RUNS ROUGH/ROLLING IDLE”.
(See NO.8 ENGINE RUNS ROUGH/ROLLING IDLE [MZR 1.3, MZR 1.5].)
No
Go to the next step.
2
DETERMINE IF MALFUNCTION CAUSE IS A/C SYSTEM OR OTHER
•  Turn off the A/C switch and fan switch.
•  Does the A/C magnetic clutch engage?
Yes
Go to the 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 [MZR 1.3, MZR 1.5].)
No
Go to the next step.
3
INSPECT INTAKE-AIR SYSTEM FOR AIR LEAKAGE
•  Inspect the following:
―  Proper routing and no damage to the vacuum lines
―  No air leakage from the intake-air system
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
Repeat Step 3.
No
Go to the next step.
4
VERIFY PCM DTC
•  Perform the PCM DTC inspection using the M-MDS.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 1.3, MZR 1.5].)
No
Go to the next step.
5
INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION
•  Perform the Drive-by-wire Control System Inspection.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
6
DETERMINE IF MALFUNCTION CAUSE IS EVAPORATIVE EMISSION CONTROL SYSTEM OR OTHER
•  Disconnect the vacuum hose between purge solenoid valve and intake manifold from 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.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.3, MZR 1.5].)
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
7
VERIFY CURRENT INPUT SIGNAL STATUS
Caution
•  While performing this step, always operate the vehicle in a safe and lawful manner.
•  When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later.
•  Access the following PIDs using the M-MDS:
―  APP1
―  APP2
―  BOO
―  TP1
―  TP2
―  MAF
―  VSS
―  CPP (MTX)
―  CPP/PNP (MTX)
―  TR (ATX, CVT)
•  Monitor the each PID while driving the vehicle.
Are all PIDs normal?
Yes
Go to the next step.
No
APP1, APP2 PIDs are not as specified:
•  Inspect the APP sensor and related wiring harness.
TP1, TP2, TP REL PIDs are not as specified:
•  Inspect the TP sensor and related wiring harness.
MAF PID is not as specified:
•  Inspect the MAF sensor and related wiring harness.
VSS PID is not as specified:
•  Inspect the VSS and related wiring harness. (ATX)
•  Inspect the ABS wheel-speed sensor. (MTX, CVT)
BOO PID is not as specified:
•  Inspect the brake switch and related wiring harness.
CPP PID is not as specified: (MTX)
•  Inspect the CPP switch and related wiring harness.
CPP/PNP PID is not as specified: (MTX)
•  Inspect the neutral switch and related wiring harness.
TR PID is not as specified: (ATX)
•  Inspect the TR switch and related wiring harness.
Repair or replace the malfunctioning part according to the inspection results.
8
VERIFY CURRENT INPUT SIGNAL STATUS
•  Access the following PIDs using the M-MDS:
―  AC_REQ
―  COLP
•  Are the PID values normal?
Yes
Intermittent concern exists.
•  Perform the “INTERMITTENT CONCERN TROUBLESHOOTING” procedure.
No
AC_REQ PID is not as specified:
•  Inspect the climate control unit terminal R (full-auto air conditioner)/K (manual air conditioner), refrigerant pressure switch (high and low pressure) and evaporator temperature sensor.
COLP PID is not as specified:
•  Inspect the refrigerant pressure switch (middle pressure).
Repair or replace the malfunctioning part according to the inspection results.
9
Verify test results.
•  If normal, return to the diagnostic index to service any additional symptoms.
•  If the malfunction remains, inspect the related Service Information and perform the repair or diagnosis.
―  If the vehicle is repaired, troubleshooting is completed.
―  If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM.