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Home >> Mazda >> 2021 >> CX-3 AWD >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting - Engine >> No. 5 Engine Stalls-After Start/At Idle >> Diagnostic Procedure

Diagnostic Procedure

NO. 5 ENGINE STALLS-AFTER START/AT IDLE DIAGNOSTIC PROCEDURE

STEP INSPECTION RESULTS ACTION
1 VERIFY TIMING OCCURRING MALFUNCTION
  • Verify the symptom.
  • Does the malfunction symptom occur just after the engine is started?
Yes Perform the symptom troubleshooting "NO. 4 HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK".
(See NO. 4 HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK .)
No Go to the next step.
2 VERIFY IF MALFUNCTION INCLUDES ROUGH IDLING
  • Verify the symptom.
  • Does the engine idle rough?
Yes Perform the symptom troubleshooting "NO. 8 ENGINE RUNS ROUGH/ROLLING IDLE".
(See NO. 8 ENGINE RUNS ROUGH/ROLLING IDLE .)
No Go to the next step.
3 VERIFY IF MALFUNCTION CAUSE IS OVERHEATING
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 ECT PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST .)
  • Is the ECT PID value less than 116°C {241°F} during driving?
Yes Go to the next step.
No The cause of this concern could be from the cooling system overheating.
4 VERIFY PCM DTC
Yes Go to the applicable DTC inspection.
(See DTC TABLE .)
No Go to the next step.
5 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: (See ON-BOARD DIAGNOSTIC TEST .)
    • APP1
    • APP2
    • ECT
    • MAF
    • MAP
    • MAP_V
    • O2S11
    • O2S12
    • SHRTFT1
      • LONGFT1
  • Do the PIDs indicate the correct values under the trouble condition? (See PCM INSPECTION .)
Yes Go to the next step.
No APP1, APP2 PIDs are not as specified:

ECT PID is not as specified:

MAF PID is not as specified:

MAP, MAP_V PIDs are not as specified:

O2S11, SHRTFT1, LONGFT1 PIDs are not as specified:

O2S12 PID is not as specified:

Repair or replace the malfunctioning part according to the inspection results.
6 INSPECT PCM POWER SUPPLY VOLTAGE
Yes Go to the next step.
No Without coolant control valve
  • Repair or replace the wiring harness between main relay terminal C and PCM terminal 2S and 1CK.

With coolant control valve
  • Repair or replace the wiring harness between main relay terminal C and PCM terminal 2BO and 2BR.
7 INSPECT A/C CUT-OFF CONTROL SYSTEM OPERATION
Yes Go to the next step.
No Perform the symptom troubleshooting "NO. 23 A/C DOES NOT WORK SUFFICIENTLY" and "NO. 24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY". (See NO. 23 A/C DOES NOT WORK SUFFICIENTLY .)
(See NO. 24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY .)
8 DETERMINE IF MALFUNCTION CAUSE IS DRIVE-BY-WIRE CONTROL SYSTEM OR OTHER
  • Will the engine run smoothly at part throttle?
Yes Go to Step 10.
No Go to the next step.
9 INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION
Yes Visually inspect the throttle body (damage/scratching).
  • If there is any malfunction:
    • Repair or replace the malfunctioning part according to the inspection results.
  • If there is no malfunction:
    • Go to the next step.
No Repair or replace the malfunctioning part according to the inspection results.
10 INSPECT PURGE CONTROL SYSTEM OPERATION
Yes Go to the next step.
No Repair or replace the malfunctioning part according to the inspection results.
11 INSPECT MAF SENSOR GROUND CIRCUIT FOR OPEN CIRCUIT
  • Inspect the MAF sensor for the following:

Without coolant control valve
  • MAF sensor terminal B voltage (ground circuit)

With coolant control valve
  • MAF sensor terminal A voltage (ground circuit)
  • Is there any malfunction?
Yes Repair or replace the suspected wiring harness.
No Go to the next step.
12 INSPECT PCM FOR POOR GROUND
  • Verify the PCM ground point condition.
  • Is there any ground point loose or lifting in the PCM?
Yes Repair the ground point.
No Go to the next step.
13 INSPECT RELATED PART CONDITION
  • Inspect the following:
    • Fuel quality (proper octane, contamination, winter/summer blend)
    • Intake-air system leakage or restriction
    • Electrical connectors
    • Poor connection for PCM ground and body ground
    • Fuel leakage
    • Vacuum leakage
    • CKP sensor and intake CMP sensor
Yes Service if necessary.
  • Repeat this step.
No Go to the next step.
14 INSPECT FUEL PRESSURE (HIGH-SIDE)
  • Start the engine and warm it up completely.
  • Access the FUEL_PRES PID using the M-MDS at idle. (See ON-BOARD DIAGNOSTIC TEST .)
  • Is the FUEL_PRES PID value approx. 3 MPa {31 kgf/cm2 , 435 psi} (Without coolant control valve)/approx. 10 MPa {102 kgf/cm2 , 1450 psi} (With coolant control valve)?
Yes Go to Step 18.
No Lower than approx. 3 MPa {31 kgf/cm2 , 435 psi} (Without coolant control valve)/approx. 10 MPa {102 kgf/cm2 , 1450 psi} (With coolant control valve):
  • If there is any malfunction:
    • Repair or replace the malfunctioning part according to the inspection results.
  • If there is no malfunction:
    • Go to Step 17.

Higher than approx. 3 MPa {31 kgf/cm2 , 435 psi} (Without coolant control valve)/approx. 10 MPa {102 kgf/cm2 , 1450 psi} (With coolant control valve):
  • Go to the next step.
15 DETERMINE IF MALFUNCTION CAUSE IS FUEL PRESSURE SENSOR OR HIGH PRESSURE FUEL PUMP
  • Is the vehicle acceleration performance normal?
Yes Go to the next step.
No Go to Step 17.
16 INSPECT FUEL PRESSURE SENSOR
Yes Replace the fuel distributor.
(See FUEL INJECTOR REMOVAL/INSTALLATION .)
No Go to Step 18.
17 INSPECT SPILL VALVE CONTROL SOLENOID VALVE CONTROL CIRCUIT FOR SHORT TO GROUND
  • Switch the ignition off.
  • Disconnect the high pressure fuel pump and PCM connectors.
  • Inspect for continuity between high pressure fuel pump terminal A (wiring harness-side) and body ground.
  • Is there continuity?
Yes Refer to the wiring diagram and verify whether or not there is a common connector between high pressure fuel pump terminal A and PCM terminal 1EE (Without coolant control valve)/1DI (With coolant control valve).
If there is a common connector:
  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
  • Repair or replace the malfunctioning part.

If there is no common connector:
  • Repair or replace the wiring harness which has a short to ground.

If the malfunction remains:
No Replace the high pressure fuel pump.
(See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION .)
18 INSPECT FUEL PRESSURE (LOW-SIDE)
  • Connect the fuel pressure gauge between fuel pump and high pressure fuel pump.
  • Measure the low side fuel pressure. (See FUEL LINE PRESSURE INSPECTION .)
  • Is the low side fuel pressure within specification?

Specification:
  • 425-505 kPa {4.34-5.14 kgf/cm2 , 61.7-73.2 psi}
Yes Go to the next step.
No Inspect the following:
  • Fuel line restriction
  • Fuel filter clogged
    • If there is any malfunction:
      • Repair or replace the malfunctioning part according to the inspection results.
  • If there is no malfunction:
19 INSPECT FUEL INJECTOR OPERATION
Yes Go to the next step.
No Repair or replace the malfunctioning part according to the inspection results.
20 INSPECT ENGINE COMPRESSION
  • Measure the compression pressure for each cylinder. (See COMPRESSION INSPECTION .)
  • Are compression pressures within specification?
Yes Go to Step 26.
No Go to the next step.
21 INSPECT ELECTRIC VARIABLE VALVE TIMING DRIVER
Yes Replace the electric variable valve timing motor/driver.
(See ELECTRIC VARIABLE VALVE TIMING MOTOR/DRIVER REMOVAL/INSTALLATION .)
No Go to the next step.
22 INSPECT ELECTRIC VARIABLE VALVE TIMING MOTOR
Yes Replace the electric variable valve timing motor/driver.
(See ELECTRIC VARIABLE VALVE TIMING MOTOR/DRIVER REMOVAL/INSTALLATION .)
No Go to the next step.
23 INSPECT ELECTRIC VARIABLE VALVE TIMING ACTUATOR
Yes Replace the electric variable valve timing actuator.
(See ELECTRIC VARIABLE VALVE TIMING ACTUATOR, HYDRAULIC VARIABLE VALVE TIMING ACTUATOR REMOVAL/INSTALLATION .)
No Go to the next step.
24 INSPECT HYDRAULIC VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION
Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
25 INSPECT FOR MALFUNCTION DUE TO DEVIATED VALVE TIMING
Yes Inspect for the following engine internal parts:
  • Cylinder
  • Piston ring
  • Intake valve
  • Exhaust valve
  • Such as cylinder head gasket
    • If there is any malfunction:
      • Repair or replace the malfunctioning part according to the inspection results.
No Adjust the valve timing to the correct timing.
26 INSPECT IGNITION SYSTEM OPERATION
Yes Go to the next step.
No Repair or replace the malfunctioning part according to the inspection results.
27 INSPECT EXHAUST SYSTEM FOR RESTRICTION
  • Inspect for restriction in the exhaust system and the TWC.
  • Is there any restriction?
Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
28 INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR INJECTOR DRIVER (PCM INTEGRATED)
Yes Replace the PCV valve.
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION .)
No Injector driver malfunction.

If the problem remains, overhaul the engine.
29 Verify the test results.
  • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX .)
  • If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis.
    • If the vehicle is repaired, troubleshooting is completed.
      • If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.