Intention of troubleshooting procedure

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

Step 1-2
- Perform an engine coolant-related inspection.
Step 3
- Perform an engine coolant passage assembly condition-related inspection.
Step 4
- Perform a unit inspection of the thermostat.
Step 5-6
- Perform a PCM input signal part-related inspection.
Step 7-8
- Verify that the primary malfunction is resolved and there are no other malfunctions.

STEP	INSPECTION	RESULTS	ACTION
1	PURPOSE: DETERMINE IF ENGINE COOLANT USED AFFECTS CONDITION BY VERIFYING WITH CUSTOMER AND INSPECTING COLOR, ODOR, AND FOAMING DUE TO POSSIBILITY OF ENGINE COOLANT FREEZING IF ENGINE COOLANT CONCENTRATION IS LOW Is the specified engine coolant being used?	Yes	Go to the next step.
1		No	Replace the engine coolant, then go to Step 7. (Advise the customer to use specified engine coolant used.) (See ENGINE COOLANT REPLACEMENT [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)
2	PURPOSE: VERIFY THAT THERE IS NO ENGINE COOLANT LEAKAGE OR FOREIGN MATTER PENETRATION BECAUSE ECT SENSOR MAY NOT MEASURE CORRECT TEMPERATURE DUE TO ENGINE COOLANT LEAKAGE Perform the "ENGINE COOLANT LEAKAGE INSPECTION". (See ENGINE COOLANT LEAKAGE INSPECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Is there engine coolant leakage or foreign matter penetration?	Yes	If there is engine coolant leakage: Repair or replace the malfunctioning location and refill the system with engine coolant. If there is foreign matter penetration: Replace engine coolant after removing the foreign matter. (See ENGINE COOLANT REPLACEMENT [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Go to Step 7.
2		No	Go to the next step.
3	PURPOSE: VERIFY IF ENGINE COOLANT PASSAGE IS CORRECT BECAUSE CORRECT ENGINE COOLANT TEMPERATURE CANNOT BE DETERMINED IF ENGINE COOLANT PASSAGE IS INCORRECT Is the engine coolant passage (such as hose) connected correctly? (ask customer if engine coolant passage has been serviced somewhere other than Authorized Mazda Dealer)	Yes	Go to the next step.
3		No	Connect engine coolant passage correctly, then go to Step 7.
4	PURPOSE: EXAMINE THERMOSTAT BECAUSE ENGINE COOLANT TEMPERATURE INCREASE SLOWS IF THERMOSTAT IS STUCK OPEN Inspect the thermostat. (See THERMOSTAT INSPECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Is there any malfunction?	Yes	Replace the thermostat, then go to Step 7. (See THERMOSTAT REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)
4		No	Go to the next step.
5	PURPOSE: EXAMINE ECT SENSOR BECAUSE ENGINE COOLANT TEMPERATURE CANNOT BE MEASURED CORRECTLY IF ECT SENSOR IS MALFUNCTIONING Inspect the ECT sensor No. 1 and ECT sensor No. 2. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Is there any malfunction?	Yes	Replace the ECT sensor No. 1 or ECT sensor No. 2, then go to Step 7. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)
5		No	Go to the next step.
6	PURPOSE: VERIFY ASSEMBLY CONDITION BECAUSE ENGINE COOLANT TEMPERATURE CANNOT BE MEASURED CORRECTLY IF ECT SENSOR IS NOT ASSEMBLED CORRECTLY Verify the ECT sensor No. 1 and ECT sensor No. 2 assembly conditions. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Are the ECT sensor No. 1 and ECT sensor No. 2 assembled correctly?	Yes	Go to the next step.
6		No	Assemble the ECT sensor No. 1 and ECT sensor No. 2 correctly, then go to the next step. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)
7	PURPOSE: VERIFICATION OF VEHICLE REPAIR COMPLETION Always reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS. (See CLEARING DTC [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5) .) Implement the repeatability verification procedure. (See REPEATABILITY VERIFICATION PROCEDURE .) Perform the Pending Trouble Code Access Procedure. (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5) .) Is the PENDING CODE for this DTC present?	Yes	Repeat the inspection from Step 1 of the troubleshooting diagnostic procedure. If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Go to the next step.
7		No	Go to the next step.
8	PURPOSE: VERIFY IF THERE IS ANY OTHER MALFUNCTION Is any other DTC or pending code stored?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5) .)
8		No	DTC troubleshooting completed.