Diagnostic Procedure

WARNING: This page is about a different car, the 2016 Mazda CX-5. However, it is still accessible from the selected car via links, so may be relevant.

STEP	INSPECTION	RESULTS	ACTION
1	DETERMINE IF MALFUNCTION CAUSE IS OVERHEATING OR OTHER Access the ECT PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST .) 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. Is the ECT PID value less than 116 °C {241 °F} during driving?	Yes	Go to the next step.
1		No	The cause of this concern could be from the cooling system overheating. Perform the symptom troubleshooting "NO. 17 COOLING SYSTEM CONCERNS-OVERHEATING". (See NO. 17 COOLING SYSTEM CONCERNS-OVERHEATING .)
2	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE .)
2		No	Go to the next step.
3	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 .) ECT MAF MAP MAP_V O2S11 O2S12 SHRTFT1 LONGFT1 Do the PIDs indicate the correct values under the malfunction condition? (See PCM INSPECTION .)	Yes	Go to the next step.
3		No	ECT PID is not as specified: Inspect the ECT sensor No. 1. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION .) MAF PID is not as specified: Inspect the MAF sensor. (See MASS AIR FLOW (MAF) SENSOR INSPECTION .) MAP, MAP_V PIDs are not as specified: Inspect the MAP sensor. (See MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR INSPECTION .) O2S11, SHRTFT1, LONGFT1 PIDs are not as specified: Inspect the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION .) O2S12 PID is not as specified: Inspect the HO2S. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION .) Repair or replace the malfunctioning part according to the inspection results. If the malfunction remains: Perform the "INTERMITTENT CONCERN TROUBLESHOOTING" procedure. (See INTERMITTENT CONCERN TROUBLESHOOTING .)
4	DETERMINE IF MALFUNCTION CAUSE IS DRIVE-BY-WIRE CONTROL SYSTEM OR OTHER Will the engine run smoothly at part throttle?	Yes	Go to Step 6.
4		No	Go to the next step.
5	INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION Perform the Electronic Control Throttle Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION .) 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 part according to the inspection results. If there is no malfunction: Go to the next step.
5		No	Repair or replace the malfunctioning part according to the inspection results.
6	INSPECT FUEL INJECTOR OPERATION Perform the Fuel Injector Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION .) Do the fuel injectors operate properly?	Yes	Go to the next step.
6		No	Repair or replace the malfunctioning part according to the inspection results.
7	INSPECT PURGE CONTROL SYSTEM OPERATION Perform the Purge Control System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION .) Does the purge solenoid valve work properly?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning part according to the inspection results.
8	INSPECT MAF SENSOR Inspect the MAF sensor for the following: Contamination Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
8		No	Go to the next step.
9	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.
9		No	Go to the next step.
10	INSPECT RELATED PART CONDITION Inspect the following: Fuel quality (proper octane, contamination, winter/summer blend) Fuel leakage Intake-air system leakage or restriction Vacuum leakage Engine oil viscosity CKP sensor, intake CMP sensor and exhaust CMP sensor Installation condition (See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION .) (See CAMSHAFT POSITION (CMP) SENSOR REMOVAL/INSTALLATION .) Damaged trigger wheel, intake camshaft and exhaust camshaft Is there any malfunction?	Yes	Service if necessary. Repeat this step.
10		No	Go to the next step.
11	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/cm ² , 435 psi}?	Yes	Go to Step 15.
11		No	Lower than 3 MPa {31 kgf/cm ² , 435 psi}: Inspect the following: Fuel leakage at the fuel line and fuel injector Fuel pump Perform the Fuel Pump (Low-pressure Side) Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION .) Fuel pressure sensor (See FUEL PRESSURE SENSOR INSPECTION .) High pressure fuel pump (See HIGH PRESSURE FUEL PUMP INSPECTION .) If there is any malfunction: Repair or replace the malfunctioning part according to the inspection results. If there is no malfunction: Go to Step 14. Higher than 3 MPa {31 kgf/cm ² , 435 psi}: Go to the next step.
12	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.
12		No	Go to Step 14.
13	INSPECT FUEL PRESSURE SENSOR Inspect the fuel pressure sensor. (See FUEL PRESSURE SENSOR INSPECTION .) Is there any malfunction?	Yes	Replace the fuel distributor. (See FUEL INJECTOR REMOVAL/INSTALLATION .)
13		No	Go to Step 15.
14	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. 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: Replace the PCM. (damage to driver in PCM) (See PCM REMOVAL/INSTALLATION .)
14		No	Replace the high pressure fuel pump. (See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION .)
15	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: 405-485 kPa {4.13-4.94 kgf/cm ² , 58.8-70.3 psi}	Yes	Go to the next step.
15		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: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION .)
16	INSPECT STARTING SYSTEM Inspect the starting system. (See STARTER INSPECTION .) Does the starting system work properly?	Yes	Go to the next step.
16		No	Repair or replace the malfunctioning part according to the inspection results.
17	INSPECT ENGINE COMPRESSION Measure the compression pressure for each cylinder. (See COMPRESSION INSPECTION .) Are compression pressures within specification? Specification: Compression [SKYACTIV-G 2.0] Standard: 885 kPa {9.02 kgf/cm ² , 128 psi} (300 rpm) Minimum: 708 kPa {7.22 kgf/cm ² , 103 psi} (300 rpm) Maximum difference between cylinders: 150 kPa {1.53 kgf/cm ² , 21.8 psi} (300 rpm) Compression [SKYACTIV-G 2.5] Standard: 954 kPa {9.73 kgf/cm ² , 138 psi} (300 rpm) Minimum: 763 kPa {7.78 kgf/cm ² , 111 psi} (300 rpm) Maximum difference between cylinders: 161 kPa {1.64 kgf/cm ² , 23.4 psi} (300 rpm) NOTE: Because the SKYACTIV-G 2.0 and SKYACTIV-G 2.5 retards the intake valve closing timing, compression pressure is low.	Yes	Go to the next step.
17		No	Inspect the following: Damaged valve seat Worn valve stem and valve guide Worn or stuck piston ring Worn piston, piston ring or cylinder Improper intake valve timing Improper exhaust valve timing Service if necessary.
18	INSPECT IGNITION SYSTEM OPERATION Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION .) Is a strong blue spark visible at each cylinder?	Yes	Go to the next step.
18		No	Repair or replace the malfunctioning part according to the inspection results.
19	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.
19		No	Go to the next step.
20	INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR INJECTOR DRIVER (PCM INTEGRATED) Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION .) Is there any malfunction?	Yes	Replace the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION .)
20		No	Injector driver malfunction. Replace the PCM. (See PCM REMOVAL/INSTALLATION .) If the problem remains, overhaul the engine.
21	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.