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Home >> Mazda >> 2020 >> CX-30 Select, FWD >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting - Engine >> Engine Stalls-After Start/At Idle >> Diagnostic Procedure

Diagnostic Procedure

ENGINE STALLS - AFTER START/AT IDLE (SKYACTIV-G) 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 "HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK".
(See HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK (US) .)
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 "ENGINE RUNS ROUGH/ROLLING IDLE".
(See ENGINE RUNS ROUGH/ROLLING IDLE (US) .)
No Go to the next step.
3 VERIFY IF MALFUNCTION CAUSE IS OVERHEATING
  • Access the ECT PID using the MMDS. (See PID/DATA MONITOR INSPECTION .)
    WARNING:
    • 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.
  • 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
  • Perform the DTC inspection for the PCM. (See DTC INSPECTION .)
  • Are any DTCs displayed?
 Yes Repair the malfunctioning location according to the applicable DTC troubleshooting.
(See DTC TABLE [PCM (SKYACTIV-G (US))] .)
No Go to the next step.
5 VERIFY CURRENT INPUT SIGNAL STATUS
WARNING:
  • 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.
 Yes Go to the next step.
No APP1, APP2 PIDs are not as specified:

ECT, ECT_VOLT, ECT2, ECT2_VOLT PIDs are not as specified:

MAF PID is not as specified:

MAP, MAP_VOLT PIDs are not as specified:

A/F_SEN_CUR, SHRT_FUEL_TRIM, LONG_FUEL_TRIM PIDs are not as specified:

HO2S_OUT_VOLT PID is not as specified:

Repair or replace the malfunctioning location.
6 INSPECT MAIN RELAY POWER SUPPLY CIRCUIT FOR SHORT TO GROUND AND OPEN CIRCUIT
  • Inspect the power supply circuit for an open circuit and short to ground. (See CIRCUIT INSPECTION .)
  • Is the circuit normal?
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
7 INSPECT PCM CONNECTOR FOR MALFUNCTION
  • Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION .)
  • Are the connector and terminal normal?
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
8 INSPECT PCM POWER SUPPLY CIRCUIT FOR SHORT TO GROUND
  • Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION .)
  • Is the circuit normal?
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
9 INSPECT MAIN RELAY CONTROL CIRCUIT FOR SHORT TO GROUND
  • Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION .)
  • Is the circuit normal?
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
10 INSPECT PCM POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT
  • Inspect the applicable circuit for open circuit. (See CIRCUIT INSPECTION .)
  • Is the circuit normal?
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
11 INSPECT MAIN RELAY CONTROL CIRCUIT FOR OPEN CIRCUIT
  • Inspect the applicable circuit for open circuit. (See CIRCUIT INSPECTION .)
  • Is the circuit normal?
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
12 INSPECT A/C CUT-OFF CONTROL SYSTEM OPERATION
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
13 DETERMINE IF MALFUNCTION CAUSE IS DRIVE-BY-WIRE CONTROL SYSTEM OR OTHER
  • Will the engine run smoothly at part throttle?
 Yes Go to Step 15.
No Go to the next step.
14 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 location and perform the repair completion verification.
  • If there is no malfunction:
    • Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
15 INSPECT PURGE CONTROL SYSTEM OPERATION
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
16 INSPECT MAF SENSOR GROUND CIRCUIT FOR OPEN CIRCUIT
  • Inspect the applicable circuit for open circuit. (See CIRCUIT INSPECTION .)
  • Is the circuit normal?
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
17 INSPECT PCM FOR POOR GROUND
  • Verify the PCM ground point condition.
  • Is there any ground point loose or lifting in the PCM?
 Yes Repair or replace the malfunctioning location and perform the repair completion verification.
No Go to the next step.
18 INSPECT RELATED PART CONDITION
 Yes Repair or replace the malfunctioning location and perform the repair completion verification.
No Go to the next step.
19 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 PID/DATA MONITOR INSPECTION .)
  • Is the FUEL_PRES PID value within specification?

Specification:
  • Approx. 10 MPa {102 kgf/cm2 , 1450 psi}
 Yes Go to Step 23.
No Lower than specification:
20 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 22.
21 INSPECT FUEL PRESSURE SENSOR FOR MALFUNCTION
 Yes Go to Step 23.
No Replace the fuel distributor and perform the repair completion verification.
(See FUEL INJECTOR REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .)
(See FUEL INJECTOR REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
22 INSPECT SPILL VALVE CONTROL SOLENOID VALVE CONTROL CIRCUIT FOR SHORT TO GROUND
  • Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION .)
  • Is the circuit normal?
 Yes Replace the high pressure fuel pump and perform the repair completion verification.
(See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .)
(See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
No Repair or replace the malfunctioning location and perform the repair completion verification.
23 INSPECT FUEL PRESSURE (LOW-SIDE)

Specification:
  • 475-555 kPa {4.85-5.65 kgf/cm2 , 68.9-80.4 psi}
 Yes Go to the next step.
No Inspect the following:
24 INSPECT FUEL INJECTOR OPERATION
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
25 INSPECT ENGINE COMPRESSION
 Yes Go to Step 34.
No Go to the next step.
26 INSPECT ELECTRIC VARIABLE VALVE TIMING DRIVER FOR MALFUNCTION
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification. (See ELECTRIC VARIABLE VALVE TIMING MOTOR/DRIVER REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .) (See ELECTRIC VARIABLE VALVE TIMING MOTOR/DRIVER REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
27 INSPECT ELECTRIC VARIABLE VALVE TIMING MOTOR FOR MALFUNCTION
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
(See ELECTRIC VARIABLE VALVE TIMING MOTOR/DRIVER REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .)
(See ELECTRIC VARIABLE VALVE TIMING MOTOR/DRIVER REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
28 INSPECT ELECTRIC VARIABLE VALVE TIMING ACTUATOR FOR MALFUNCTION
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
(See ELECTRIC VARIABLE VALVE TIMING ACTUATOR, HYDRAULIC VARIABLE VALVE TIMING ACTUATOR REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .)
(See ELECTRIC VARIABLE VALVE TIMING ACTUATOR, HYDRAULIC VARIABLE VALVE TIMING ACTUATOR REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
29 INSPECT HYDRAULIC VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION
 Yes Repair or replace the malfunctioning location and perform the repair completion verification.
No Go to the next step.
30 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 location and perform the repair completion verification.
No Adjust the valve timing to the correct timing and perform the repair completion verification.
31 INSPECT IGNITION SYSTEM OPERATION
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
32 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 location and perform the repair completion verification.
No Go to the next step.
33 INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR INJECTOR DRIVER (PCM INTEGRATED)
 Yes Replace the PCV valve and perform the repair completion verification.
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .)
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
No Injector driver malfunction.

If the problem remains, overhaul the engine and perform the repair completion verification.
Repair completion verification 1 VERIFY THAT VEHICLE IS REPAIRED
  • Install/connect the part removed/disconnected during the troubleshooting procedure.
  • Has the malfunction symptom been eliminated?
 Yes Complete the symptom troubleshooting. (Explain contents of repair to customer)
No Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.
(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(US)] .)
  • If the CAN communication is normal, perform the diagnosis from Step 1.
    • If the malfunction recurs, go to the next step.
Repair completion verification 2 VERIFY IF MALFUNCTION IS CAUSED BY NOT PERFORMING PCM REPROGRAMMING
  • Verify repair information and verify that there is a new calibration in the PCM.
  • Is there a new calibration in the PCM?
 Yes Perform the PCM reprogramming and verify if the malfunction symptom was corrected.
No Replace the PCM.
(See PCM REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .)
(See PCM REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
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