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	INSPECT VEHICLE CONDITION FOR EFFECT ON MALFUNCTION Verify how the customer drives the vehicle by asking the customer the following: Because engine is started with accelerator pedal fully depressed, it goes into dechoke mode and fuel is not injected Does the engine start with the accelerator pedal fully depressed?	Yes	Explain to the customer that the vehicle is normal and give them advice on how to start the engine and a specific example of the conditions in which the engine goes into dechoke mode.
1		No	Go to the next step.
2	VERIFY IF MALFUNCTION CAUSE IS OVERHEATING 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.
2		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 .)
3	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 .)
3		No	Go to the next step.
4	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 O2S11 O2S12 SHRTFT1 LONGFT1 Do the PIDs indicate the correct values under the malfunction condition? (See PCM INSPECTION .)	Yes	Go to the next step.
4		No	APP1, APP2 PIDs are not as specified: Inspect the APP sensor. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION .) 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 .) 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 .)
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 .) 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.
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	VERIFY IF MALFUNCTION CAUSE IS MAF SENSOR SIGNAL NOTE: If the inspection in Step 8 is performed, the PCM detects a DTC and performs fail-safe control. After performing the inspection, clear DTCs using the M-MDS. Switch the ignition off. Disconnect the MAF sensor/IAT sensor No. 1 connector. Start the engine. Does the engine start normally?	Yes	Clean the MAF sensor. Verify that the symptom is solved. If the symptom remains, inspect the MAF sensor related wiring harness and connector. If there is any malfunction: Repair or replace the malfunctioning part according to the inspection results. If there is no malfunction: Replace the MAF sensor/IAT sensor No. 1. (See MASS AIR FLOW (MAF) SENSOR/INTAKE AIR TEMPERATURE (IAT) SENSOR NO. 1 REMOVAL/INSTALLATION .)
8		No	Go to the next step.
9	INSPECT FUEL INJECTOR RELAY Switch the ignition off. Remove the fuel injector relay. Inspect the fuel injector relay. (See RELAY INSPECTION .) Is there any malfunction?	Yes	Replace the fuel injector relay.
9		No	Reinstall the fuel injector relay, then go to the next step.
10	INSPECT FUEL PUMP RELAY Remove the fuel pump relay. Inspect the fuel pump relay. (See RELAY INSPECTION .) Is there any malfunction?	Yes	Replace the fuel pump relay.
10		No	Inspect for a short or open circuit between the following terminals: IG1 relay terminal C-PCM terminal 2AQ Battery positive terminal-PCM terminal 1CO Battery positive terminal-PCM terminal 1CS Battery positive terminal-PCM terminal 1CW Battery positive terminal-PCM terminal 1DA Battery positive terminal-PCM terminal 1DG Battery positive terminal-PCM terminal 1DK Main relay terminal C-Fuel injector relay terminal A Fuel injector relay terminal E-Body ground If there is any malfunction: Repair or replace the malfunctioning part according to the inspection results. If there is no malfunction: Reinstall the fuel pump relay, then go to the next step.
11	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 Fuses Fuel leakage Vacuum leakage CKP sensor and exhaust CMP sensor Installation condition (See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION .) (See CAMSHAFT POSITION (CMP) SENSOR REMOVAL/INSTALLATION .) Damaged trigger wheel exhaust camshaft Is there any malfunction?	Yes	Service if necessary. Repeat this step.
11		No	Go to the next step.
12	INSPECT FUEL PRESSURE (HIGH-SIDE) Access the FUEL_PRES PID using the M-MDS while cranking the engine. (See ON-BOARD DIAGNOSTIC TEST .) Is the FUEL_PRES PID value within specification? Specification: 4-6 MPa {41-61 kgf/cm ² , 581-870 psi}	Yes	Go to Step 14.
12		No	Lower than specification: 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 the next step. Higher than specification: Go to the next step.
13	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 .)
13		No	Replace the high pressure fuel pump. (See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION .)
14	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.
14		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 .)
15	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.
15		No	Repair or replace the malfunctioning part according to the inspection results.
16	INSPECT HYDRAULIC VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION Perform the Hydraulic Variable Valve Timing Control System Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION .) Does the hydraulic variable valve timing control system work properly?	Yes	Go to the next step.
16		No	Repair or replace the malfunctioning part according to the inspection results.
17	INSPECT FUEL TANK Inspect the fuel tank. (See FUEL TANK INSPECTION .) Is vapor occurring?	Yes	Replace the fuel tank. (See FUEL TANK REMOVAL/INSTALLATION .)
17		No	Go to the next step.
18	INSPECT HIGH PRESSURE FUEL PUMP Inspect the high pressure fuel pump. (See HIGH PRESSURE FUEL PUMP INSPECTION .) Is there any malfunction?	Yes	Replace the high pressure fuel pump. (See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION .)
18		No	Go to the next step.
19	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.
19		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.
20	INSPECT IGNITION SYSTEM OPERATION NOTE: Because the malfunction may have been resolved by removing the carbon adhered to the spark plug during the spark inspection for the spark plug, verify that the repairs have been completed. 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.
20		No	Repair or replace the malfunctioning part according to the inspection results.
21	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.
21		No	Go to the next step.
22	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 .)
22		No	Injector driver malfunction. Replace the PCM. (See PCM REMOVAL/INSTALLATION .) If the problem remains, overhaul the engine.
23	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.