Symptom Troubleshooting - Engine: Other Mazda MX-5 NC

FOREWORD [LF]

1. When the customer reports a vehicle malfunction, check the malfunction indicator lamp (MIL) indication and diagnostic trouble code (DTC), then diagnose the malfunction according to (Scheme 16): If a DTC exists, diagnose the applicable DTC inspection. (See «DTC TABLE [LF]»(ref-244449-S40344338372006092400000).) If no DTC exists and the MIL does not illuminate or flash, diagnose the applicable symptom troubleshooting. (See «QUICK DIAGNOSTIC TABLE [LF]»(ref-244450-S20373660812006092400000).)

Scheme 16

Water Sprinkling Method

If malfunction occurs only under high humidity or rainy/snowy weather, perform the following steps

Scheme 17

1. Connect the WDS or equivalent to the DLC-2 if you are inspecting sensors or switches.
2. Turn the ignition switch to the ON position (Engine off). NOTE: If the engine starts and runs, perform the following steps at idle.
3. Access PIDs for sensor or switch if you are inspecting sensors or switches.
4. If you are inspecting the switch, turn it on manually.
5. Spray water onto the vehicle or run it through a car wash. If PID value is unstable or malfunction occurs, repair or replace part if necessary.

NO.1 MELTING OF MAIN OR OTHER FUSES [LF]

MELTING OF MAIN OR OTHER FUSES POSSIBLE CAUSE 1 Related wiring harness [TROUBLESHOOTING HINTS] Inspect condition of fuse

Scheme 18

DAMAGED FUSE & RELATED WIRING HARNESS

NO.2 MIL ILLUMINATES [LF]

POSSIBLE CAUSE & DESCRIPTION (MIL ILLUMINATES [LF])

NO.3 WILL NOT CRANK [LF]

POSSIBLE CAUSE & DESCRIPTION (WILL NOT CRANK [LF])

NO.4 HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK [LF]

POSSIBLE CAUSE & DESCRIPTION (HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK [LF])

NO.5 ENGINE STALLS-AFTER START/AT IDLE [LF]

POSSIBLE CAUSE & DESCRIPTION (ENGINE STALLS-AFTER START/AT IDLE [LF])

NO.6 CRANKS NORMALLY BUT WILL NOT START [LF]

POSSIBLE CAUSE & DESCRIPTION (CRANKS NORMALLY BUT WILL NOT START [LF])

NO.7 SLOW RETURN TO IDLE [LF]

POSSIBLE CAUSE & DESCRIPTION (SLOW RETURN TO IDLE [LF])

NO.8 ENGINE RUNS ROUGH/ROLLING IDLE [LF]

POSSIBLE CAUSE & DESCRIPTION (ENGINE RUNS ROUGH/ROLLING IDLE [LF])

NO.9 FAST IDLE/RUNS ON [LF]

POSSIBLE CAUSE & DESCRIPTION (FAST IDLE/RUNS ON [LF])

NO.10 LOW IDLE/STALLS DURING DECELERATION [LF]

POSSIBLE CAUSE & DESCRIPTION (LOW IDLE/STALLS DURING DECELERATION [LF])

NO.11 ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE, SURGES [LF]

POSSIBLE CAUSE & DESCRIPTION (ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE, SURGES)

NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE [LF]

POSSIBLE CAUSE & DESCRIPTION (LACK/LOSS OF POWER-ACCELERATION/CRUISE)

NO.13 KNOCKING/PINGING-ACCELERATION/CRUISE [LF]

POSSIBLE CAUSE & DESCRIPTION (KNOCKING/PINGING-ACCELERATION/CRUISE)

NO.14 POOR FUEL ECONOMY [LF]

POSSIBLE CAUSE & DESCRIPTION (POOR FUEL ECONOMY)

NO.15 EMISSION COMPLIANCE [LF]

POSSIBLE CAUSE & DESCRIPTION (EMISSION COMPLIANCE)

NO.16 HIGH OIL CONSUMPTION/LEAKAGE [LF]

POSSIBLE CAUSE & DESCRIPTION (HIGH OIL CONSUMPTION/LEAKAGE)

NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [LF]

POSSIBLE CAUSE & DESCRIPTION (COOLING SYSTEM CONCERNS-OVERHEATING)

NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [LF]

POSSIBLE CAUSE & DESCRIPTION (COOLING SYSTEM CONCERNS-RUNS COLD)

NO.19 EXHAUST SMOKE [LF]

POSSIBLE CAUSE & DESCRIPTION (EXHAUST SMOKE)

NO.20 FUEL ODOR (IN ENGINE COMPARTMENT) [LF]

POSSIBLE CAUSE & DESCRIPTION (FUEL ODOR (IN ENGINE COMPARTMENT))

NO.23 A/C DOES NOT WORK SUFFICIENTLY [LF]

POSSIBLE CAUSE & DESCRIPTION (A/C DOES NOT WORK SUFFICIENTLY)

NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [LF]

POSSIBLE CAUSE & DESCRIPTION (A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY)

NO.25 A/C DOES NOT CUT OFF UNDER WIDE OPEN THROTTLE CONDITIONS [LF]

POSSIBLE CAUSE & DESCRIPTION (A/C DOES NOT CUT OFF UNDER WIDE OPEN THROTTLE CONDITIONS)

NO.26 EXHAUST SULPHUR SMELL [LF]

POSSIBLE CAUSE & DESCRIPTION (EXHAUST SULPHUR SMELL)

NO.28 FUEL FILLING SHUT OFF CONCERNS [LF]

POSSIBLE CAUSE & DESCRIPTION (FUEL FILLING SHUT OFF CONCERNS)

NO.29 SPARK PLUG CONDITION [LF]

POSSIBLE CAUSE & DESCRIPTION (SPARK PLUG CONDITION)

Finding Irregular Signals

While referring to ON-BOARD DIAGNOSTIC TEST [LF] , use the PID/DATA monitor and record function to inspect the input signal system relating to the problem.

1. Start the engine and idle the vehicle. You can assume that any signals that are out of specification by a wide margin are irregular.
2. When recreating the problem, any sudden change in monitor input signals that is not intentionally created by the driver can be determined as irregular.

Locating the Source Of Unusual Signals

Scheme 19

1. When an irregular signal is detected, measure the #1 PCM terminal voltage. If the #1 terminal voltage and the WDS or equivalent monitor voltage are the same, proceed to the next step. If there is a difference of 0.5 V or more , inspect for the following points concerning the PCM connector: Female terminal opening is loose. Coupler (pin holder) damage Pin discoloration (blackness) Harness/pin crimp is loose or disconnected.
2. Measure the #2 sensor terminal voltage. If there is a 0.5 V or more difference between the sensor and the WDS or equivalent voltages, inspect the wiring harness for open or short circuits. If the sensor and the WDS or equivalent voltages are the same, inspect for the following points concerning the sensor connector: Female terminal opening is loose. Coupler (pin holder) damage Pin discoloration (blackness) If there are no problems, proceed to next investigation below.

If simulation function of WPS or equivalent is used

FUEL INJECTOR OPERATION INSPECTION TABLE

If simulation function of WDS or equivalent is not used

FUEL INJECTOR OPERATION INSPECTION TABLE

If simulation function of WDS or equivalent is used

1. Warm up the engine and idle it.
2. Connect the WDS or equivalent to DLC-2.
3. Select the RPM and FUELPW1 PIDs.
4. Monitor the both PIDs while performing the following steps. Depress the accelerator pedal and increase the RPM PID to 4,000 rpm. Quickly release the accelerator pedal (brake pedal is not depressed) and verify that the FUELPW1 PID is 0 ms. , and 2-5 ms. when the RPM PID drops below 1,200 rpm. If not as specified, inspect the following. ECT sensor and related harness (See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [LF]»(ref-244452-S21398329352006092400000) .) Neutral switch and related harness (See «NEUTRAL SWITCH INSPECTION [LF]»(ref-244452-S06733949182006092400000) .) Clutch switch and related harness (See «CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [LF]»(ref-244452-S06046535002006092400000) .)

1. Warm up the engine and idle it.
2. Measure the fuel injector control signal wave profile using the oscilloscope while performing the following steps. Depress the accelerator pedal and increase the engine speed to 4,000 rpm. Quickly release the accelerator pedal (brake pedal is not depressed) and verify that the wave profile constant B+ , and appears wave, when the engine speed drops below 2,200 rpm. (See «PCM INSPECTION [LF]»(ref-244452-S30974371722006092400000) .) If not as specified, inspect the following. ECT sensor and related harness (See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [LF]»(ref-244452-S21398329352006092400000) .) Neutral switch and related harness (MT) (See «NEUTRAL SWITCH INSPECTION [LF]»(ref-244452-S06733949182006092400000) .) Clutch switch and related harness (MT) (See «CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [LF]»(ref-244452-S06046535002006092400000) .) TR switch and related wiring harness (AT) (See «TRANSMISSION RANGE (TR) SWITCH INSPECTION [SJ6A-EL]»(ref-244474-S28234354392006092400000) .)

If simulation function of WOS or equivalent is used

1. Crank the engine and verify that EGR valve operation (initial operation) sound is heard. If the operation sound is not heard, connect the WDS or equivalent to the DLC-2 and verify that the DTC P0403 is shown. Perform the DTC inspection. (See «DTC TABLE [LF]»(ref-244449-S40344338372006092400000) .)
2. Start the engine run it at idle.
3. Increase the step value of EGR valve from 0 to 52 using SEGR PID of simulation function.
4. Operate the EGR valve and inspect if the engine speed becomes unstable or the engine stalls. If the engine speed will not change, proceed to following. Stop the engine. Remove the EGR valve. Connect the EGR valve connector. Turn the ignition switch to the ON position. Increase the step value of EGR valve from 0 to 52 using SEGRP PID. Verify that the EGR valve operates according to SEGRP PID. If the EGR valve is operated, clean the EGR valve and EGR gas passage. If the EGR valve will not operate, replace the EGR valve.
5. Start the engine and warm it up completely.
6. Access the following PIDs. ECT, RPM, SEGRP, APP1, APP2, TP, VSS
7. Idle the vehicle and verify that the SEGRP value is 0.
8. Put the vehicle drive.
9. Depress the accelerator pedal and verify that the SEGRP value is increased. If the SEGRP value will not increase, inspect the VSS, TP and ECT PIDs. (See «PCM INSPECTION [LF]»(ref-244452-S30974371722006092400000) .)
10. Stop the vehicle and verify that the SEGRP value is returned to 0.

1. Crank the engine and verify that EGR valve operation (initial operation) sound is heard. If the operation sound is not heard, connect the WDS or equivalent to the DLC-2 and verify that the DTC P0403 is shown. Perform DTC inspection. (See «DTC TABLE [LF]»(ref-244449-S40344338372006092400000) .)
2. Start the engine and idle it.
3. Warm up the engine to normal operating temperature.
4. Access the following PIDs: ECT, RPM, SEGRP_DSD, APP1, APP2, VSS
5. Idle the vehicle and verify that the SEGRP value is 0.
6. Put the vehicle in drive.
7. Depress the accelerator pedal and verify that the SEGRP_DSD value is increased. If the EGR valve increases, inspect the following: EGR valve (stuck open or close) Wiring harness and connectors (Main relay-EGR valve-PCM) If the SEGRP_DSD value does not increase, inspect the VSS, APP1, APP2, TP and ECT PIDs. (See «PCM INSPECTION [LF]»(ref-244452-S30974371722006092400000) .)
8. Stop the vehicle and verify that the SEGRP value returns to 0.

1. Start the engine.
2. Disconnect the vacuum hose between the purge solenoid valve and the charcoal canister.
3. Put the finger to the purge solenoid valve and verify that there is no vacuum applied when the engine is cold. If there is a vacuum, inspect the following: Wiring harness and connectors (Purge solenoid valve-PCM terminal 2C) Purge solenoid vale (stuck open)
4. Connect the WDS or equivalent to the DLC-2 and verify that the DTC P0443 is shown. Perform the DTC inspection. (See «DTC TABLE [LF]»(ref-244449-S40344338372006092400000) .)
5. Select EVAPCP PID.
6. Increase the duty value of the purge valve to 50% and inspect if the operation sound of the valve is heard. If the operation sound is heard, inspect for the loose or damaged vacuum hose. (Intake manifold-purge solenoid valve-charcoal canister) If the operation sound is not heard, perform the purge solenoid valve inspection. (See «PURGE SOLENOID VALVE INSPECTION [LF]»(ref-244459-S20504859392006092400000) .)
7. Warm up the engine to normal operating temperature.
8. Monitor the EVAPCP PID using the WDS or equivalent, and drive the vehicle approx. 2,000 rpm for 30 sec. or more. If the EVAPCP PID is 0% , inspect the following. MAF, APP1, APP2, TP_REL and LOAD PIDs.

1. Start the engine.
2. Disconnect the vacuum hose between the purge solenoid valve and the charcoal canister.
3. Put the finger to the purge solenoid valve and verify that there is no vacuum applied when the engine is cold. If there is a vacuum, inspect the following: Wiring harness and connectors (Purge solenoid valve-PCM terminal 2C) Purge solenoid vale (stuck open)
4. Connect the WDS or equivalent to the DLC-2 and verify that the DTC P0443 is shown. Perform the DTC inspection. (See «DTC TABLE [LF]»(ref-244449-S40344338372006092400000) .)
5. Access EVAPCP and ECT PIDs.
6. Verify that the ECT PID is more than 78°C {173°F}. If the ECT PID reading indicates less than 78°C {173°F} , perform the ECT inspection.
7. Set the vehicle on the dynamometer or chassis roller. WARNING: When the dynamometer or chassis roller is operating, there is a possibility that the operator may come into contact with or be caught up in the rotating parts, leading to serious injuries or death. When performing work while the dynamometer or chassis roller is operating, be careful not to come into contact with or caught up in any of the rotating parts.
8. Drive the vehicle approx. 2,000 rpm for 30 sec. or more. If there is no vacuum, inspect the following: Wiring harness and connector (Main relay-purge solenoid valve-PCM terminal 2C) Purge solenoid valve MAF, APP1, APP2, TP and LOAD PISs If there is vacuum, inspect the following: Vacuum hose (Purge solenoid valve-charcoal canister)

1. Connect the WDS or equivalent to DLC-2.
2. Start the engine and warm it up to normal operating temperature.
3. Verify that the DTC P0480, P0481 or P0482 is not shown and cooling fan operating while the KOER self-test or the KOER self-test. (See «KOEO/KOER SELF TEST [LF]»(ref-244449-S37627504482006092400000) .)
4. Verify that the DTC P0480, P0481 or P0482 is not shown and cooling fan while operating the KOER self-test. If the DTC P0480 is shown, perform the DTC troubleshooting procedure. (See «DTC P0480 [LF]»(ref-244449-S25640152412006092400000) .) (See «DTC P0481 [LF]»(ref-244449-S21249586672006092400000) .) (See «DTC P0482 [LF]»(ref-244449-S14148814262006092400000) .) If the cooling fans do not operate while KOER self-test, proceed the followings: Inspect the cooling fan motor and wiring harness between cooling fan motor and GND. Select FAN1, FAN2 and FAN3 PIDs. Turn ignition switch off and disconnect the cooling fan motor connector. Verify that each cooling fan relay operating sound is heard, when turn each cooing fan relay to on from off using simulation function of FAN1, FAN2 and FAN3 PIDs. If the operation sound is not heard, inspect for suspected cooling fan relay is stuck open or close. If the operation sound is heard, inspect wiring harness and connector between all cooling fan relays and cooling fan motor.

1. Connect the WDS or equivalent to DLC-2.
2. Start the engine and warm it up to normal operating temperature.
3. Perform the KOER self-test. (See «KOEO/KOER SELF TEST [LF]»(ref-244449-S37627504482006092400000) .)
4. Verify that the DTC P0480, P0481 or P0482 is not shown and cooling fan operating while the KOER self-test. If the DTC P0480 is shown, perform the DTC troubleshooting procedure. (See «DTC P0480 [LF]»(ref-244449-S25640152412006092400000) .) (See «DTC P0481 [LF]»(ref-244449-S21249586672006092400000) .) (See «DTC P0482 [LF]»(ref-244449-S14148814262006092400000) .) If the cooling fans do not operate while KOER self-test, proceed the followings: Inspect the cooling fan motor and wiring harness between cooling fan motor and GND. Turn the ignition switch to off. Disconnect ECT sensor connector. Verify that the operation sound heard form all cooling fan relays (No.1, No.2 and No.3), when the ignition switch to ON position. If the operation sound is not heard, inspect for suspected cooling fan relay is stuck open or close. If the operation sound is heard, inspect wiring harness and connector between all cooling fan relays and cooling fan motor. Turn the ignition switch off and disconnect the ECT sensor connector. Reconnect the ECT sensor and clear the DTC from PCM memory using the WDS or equivalent.

1. Warm up the engine to normal operating temperature.
2. Connect the WDS or equivalent to DLC-2.
3. Start the engine and run it at idle.
4. Select VT DUTY1 PID.
5. Increase the oil control valve (OCV) duty value and verify that the engine idles roughly or stalls. If as specified, inspect the timing belt component (valve timing deviation). If not as specified, go to the next step.
6. Remove the oil control valve (OCV) with connector is connected.
7. Turn the ignition switch to the ON position.
8. Select VT DUTY1 PID.
9. Increase the oil control valve (OCV) duty value and verify that the spool valve operates in the advance direction. If as specified, inspect the following hydraulic passage for clogging and/or leakage. Oil pressure switch-oil control valve (OCV) Oil control valve (OCV)-camshaft Camshaft internal passage If not as specified, inspect the following: Oil control valve (OCV) operation Harness and connectors for open or short (Oil control valve (OCV)-PCM terminal 2E)
10. If they are okay, replace the intake camshaft pulley (with a built-in variable valve timing actuator).

1. Start the engine and run it at idle. If idling cannot be continued, go to Step 2 . If idling can be continued, go to Step 7 .
2. Remove the oil control valve (OCV) and verify that the spool valve is at maximum retard position.
3. Connect the oil control valve (OCV).
4. Turn the ignition switch to the ON position.
5. Verify that the spool valve is at maximum retard position. If the spool valve is stuck in the advance direction, inspect for the following: Short circuit in wiring harnesses or connectors between the oil control valve (OCV) and the PCM.
6. Inspect the variable valve timing actuator. (See «VARIABLE VALVE TIMING ACTUATOR INSPECTION [LF]»(ref-244453-S12756088732006092400000) .)
7. Disconnect oil control valve (OCV) connector.
8. Warm up the engine and idle it.
9. Apply battery voltage to the oil control valve (OCV) and verify that the engine idles roughly or stalls. If the engine idles roughly or stalls, inspect the timing belt component (valve timing deviation). If the engine does not idle roughly or stalls, go to the next step.
10. Remove the oil control valve (OCV) and perform spool valve operation inspection. (See «OIL CONTROL VALVE (OCV) INSPECTION [LF]»(ref-244453-S19001742712006092400000) .) If not as specified, inspect the following: Oil control valve (OCV) Harnesses and connectors between oil control valve (OCV) and PCM open or short. If as specified, inspect the following hydraulic passages for clogging or leakage or both: Oil pressure switch-oil control valve (OCV) Oil control valve (OCV)-camshaft Camshaft internal passage
11. If they are normal, replace the camshaft pulley (with built-in variable valve timing actuator).

EVAP System Malfunction Judgment

1. The PCM calculates the stored air pump load current value and send the results to the WDS as DTCs

DTC & CONDITION TABLE