Diagnostic Procedure

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5] .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [SKYACTIV-G 2.5] .)
1		No	Go to the next step.
2	REPLACE FUEL Drain the remaining fuel in the fuel tank and add the specified fuel. Leave idling for approx. 15 min to refill the hose with fuel. Does the symptom disappear?	Yes	Symptom troubleshooting completed. (If customer has used fuel additive, give them advice not to use it)
2		No	Go to the next step.
3	VERIFY IF MALFUNCTION CAUSE IS OVERHEATING Access the ECT PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5] .) 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.
3		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 [SKYACTIV-G 2.5] .)
4	VERIFY SPARK PLUG CONDITION Remove all spark plugs. (See SPARK PLUG REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .) Inspect the spark plug. (See SPARK PLUG INSPECTION [SKYACTIV-G 2.5] .) Is there any malfunction?	Yes	Replace the spark plug. (See SPARK PLUG REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .)
4		No	Go to the next step.
5	INSPECT INTAKE AIR SYSTEM FOR AIR SUCTION Verify if there is air suction into the intake air system (such as between MAF sensor and intake valve, vacuum hose). Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
5		No	Go to the next step.
6	INSPECT MAP SENSOR Access the following PIDs using the M-MDS: (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5] .) MAP BARO Measure the intake manifold vacuum when idling (no load). (See INTAKE MANIFOLD VACUUM INSPECTION [SKYACTIV-G 2.5] .) Does the difference between PIDs BARO and MAP nearly match the intake manifold vacuum value?	Yes	Go to the next step.
6		No	Replace the MAP sensor/IAT sensor No. 2. (See MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR/INTAKE AIR TEMPERATURE (IAT) SENSOR NO. 2 REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .)
7	INSPECT MAF SENSOR Inspect the MAF sensor. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [SKYACTIV-G 2.5] .) Is there any malfunction?	Yes	Replace the MAF sensor/IAT sensor No. 1. (See MASS AIR FLOW (MAF) SENSOR/INTAKE AIR TEMPERATURE (IAT) SENSOR NO. 1 REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .)
7		No	Go to the next step.
8	INSPECT IAT SENSOR NO. 2 Inspect the IAT sensor No. 2 resistance. (See INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTION [SKYACTIV-G 2.5] .) Is there any malfunction?	Yes	Replace the MAP sensor/IAT sensor No. 2. (See MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR/INTAKE AIR TEMPERATURE (IAT) SENSOR NO. 2 REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .)
8		No	Go to the next step.
9	INSPECT ECT SENSOR NO. 1 Inspect the ECT sensor No. 1 resistance. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [SKYACTIV-G 2.5] .) Is there any malfunction?	Yes	Replace the ECT sensor No. 1. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .)
9		No	Go to the next step.
10	INSPECT KS Inspect the KS. (See KNOCK SENSOR (KS) INSPECTION [SKYACTIV-G 2.5] .) Is there any malfunction?	Yes	Replace the KS, then go to the next step. (See KNOCK SENSOR (KS) REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .)
10		No	Remove the accumulated matter in the cylinder head using the following procedure: Carbon remover Overhauling Go to the next step.
11	Verify the test results. If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.5] .) 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.