Diagnostic Procedure

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.

FAST IDLE/RUNS ON (SKYACTIV-G, US) DIAGNOSTIC PROCEDURE

Step	Inspection	Results	Action
1	INSPECT COOLING SYSTEM FOR MALFUNCTION Access the ECT PID using the MMDS. (See PID/DATA MONITOR INSPECTION .) Start the engine and warm it up completely. Is the ECT PID value between 82-112°C {180-234°F}?	Yes	Go to the next step.
1		No	ECT PID value is higher than 112°C {234°F}: Perform the symptom troubleshooting "COOLING SYSTEM CONCERNS-OVERHEATING". (See COOLING SYSTEM CONCERNS-OVERHEATING (US) .) ECT PID value is less than 82°C {180°F}: Perform the symptom troubleshooting "COOLING SYSTEM CONCERNS-RUNS COLD". (See COOLING SYSTEM CONCERNS-RUNS COLD .)
2	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))] .)
2		No	Go to the next step.
3	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. Access the following PIDs using the M-MDS: (See PID/DATA MONITOR INSPECTION .) APP1 APP2 CLTCH_PEDAL_POS (MTX) ECT ECT_VOLT ECT2 ECT2_VOLT A/F_SEN_CUR HO2S_OUT_VOLT SHRT_FUEL_TRIM LONG_FUEL_TRIM Do the PIDs indicate the correct values under the malfunction condition? (See PID/DATA MONITOR TABLE [PCM (SKYACTIV-G (US))] .)	Yes	Go to the next step.
3		No	APP1, APP2 PIDs are not as specified: Inspect the APP sensor No. 1 and No. 2. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [SKYACTIV-G (VIN M (US))] .) (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [SKYACTIV-G (VIN L (US))] .) CLTCH_PEDAL_POS PID is not as specified: (MTX) Inspect the clutch stroke sensor. (See CLUTCH STROKE SENSOR INSPECTION [SKYACTIV-G (VIN L (US))] .) ECT, ECT_VOLT, ECT2, ECT2_VOLT PIDs are not as specified: Inspect the ECT sensor No. 1 and No. 2. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [SKYACTIV-G (VIN M (US))] .) (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [SKYACTIV-G (VIN L (US))] .) A/F_SEN_CUR, SHRT_FUEL_TRIM, LONG_FUEL_TRIM PIDs are not as specified: Inspect the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [SKYACTIV-G (VIN M (US))] .) (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [SKYACTIV-G (VIN L (US))] .) HO2S_OUT_VOLT PID is not as specified: Inspect the HO2S. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [SKYACTIV-G (VIN M (US))] .) (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [SKYACTIV-G (VIN L (US))] .) Repair or replace the malfunctioning location. If the malfunction remains: Inspect communication error between TCM and PCM. (ATX) Repair or replace the malfunctioning location and perform the repair completion verification. Perform the "Action for Non-repeatable Malfunction" procedure. (See TROUBLESHOOTING PROCEDURE [(US)] .)
4	DETERMINE IF MALFUNCTION CAUSE IS A/C REQUEST SIGNAL OR OTHER Access the A/C_REQ PID using the M-MDS. (See PID/DATA MONITOR INSPECTION .) Monitor the A/C_REQ PID while turning on and off the air conditioner using the switch on the control panel. Does the A/C_REQ PID value change from on to off according to switch control panel?	Yes	Go to the next step.
4		No	If the A/C_REQ PID is always ON: Perform the symptom troubleshooting "A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY". (See A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY .) If the A/C_REQ PID is always OFF: Perform the symptom troubleshooting "A/C DOES NOT WORK SUFFICIENTLY". (See A/C DOES NOT WORK SUFFICIENTLY .)
5	DETERMINE IF MALFUNCTION CAUSE IS DRIVE-BY-WIRE CONTROL SYSTEM OR OTHER Will the engine run smoothly at part throttle?	Yes	Go to Step 7.
5		No	Go to the next step.
6	INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION Perform the Electronic Control Throttle Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION (US) .) Does the drive-by-wire control system work properly?	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.
6		No	Repair or replace the malfunctioning location and perform the repair completion verification.
7	INSPECT FUEL INJECTOR OPERATION Perform the Fuel Injector Operation Inspection. (See FUEL INJECTOR INSPECTION [SKYACTIV-G (VIN M (US))] .) (See FUEL INJECTOR INSPECTION [SKYACTIV-G (VIN L (US))] .) Do the fuel injectors operate properly?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning location and perform the repair completion verification.
8	INSPECT HIGH PRESSURE FUEL PUMP Inspect the high pressure fuel pump. (See HIGH PRESSURE FUEL PUMP INSPECTION [SKYACTIV-G (VIN M (US))] .) (See HIGH PRESSURE FUEL PUMP INSPECTION [SKYACTIV-G (VIN L (US))] .) Is there any malfunction?	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))] .)
8		No	Go to the next step.
9	INSPECT INTAKE-AIR SYSTEM FOR AIR LEAKAGE Inspect for leakage in intake-air system. Is there any leakage?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification.
9		No	Injector driver malfunction. Replace the PCM. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .) (See PCM REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .) 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)
Repair completion verification 1		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. If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .) (See PCM REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
Repair completion verification 2		No	Replace the PCM. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .) (See PCM REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)