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2008 - MX-5 - Engine

ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF]

Input Signal System Inspection Procedure

1. Find an irregular signal. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF].)
2. Locate source. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF].)
3. Repair or replace the malfunctioning part.
4. Confirm that the irregular signal is no longer detected.
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

CAUTION:

Variable resistance type 1 (TP sensor and EGR boost sensor)

Input signal system inspection for variable resistance type 1
1. When an irregular signal is detected, measure the #1 PCM terminal voltage.
2. Measure the #2 sensor terminal voltage.
Standard power supply system inspection for variable resistance type 1
GND system inspection for variable resistance type 1
Variable resistance type 2 (mass air flow (MAF) sensor and VSS)

GND system inspection for variable resistance type 2
Input signal system inspection for variable resistance type 2
1. When an irregular signal is detected, measure the #1 PCM terminal voltage.
2. Measure the #2 sensor terminal voltage.
Electrical supply system inspection for variable resistance type 2
Thermistor type (IAT sensor and ECT sensor)

Input signal system inspection for thermistor type
1. When an irregular signal is detected, measure the #1 PCM terminal voltage.
2. Measure the #2 sensor terminal voltage.
GND system inspection for thermistor type

Main Relay Operation Inspection

1. Verify that the main relay clicks when the ignition switch is turned to ON position and off.

Intake Manifold Vacuum Inspection

1. Verify that the intake air hoses are installed securely.
2. Disconnect the vacuum hose connecting the intake manifold and the purge solenoid valve (purge solenoid valve side) and install the vacuum gauge.
3. Warm up the engine.
4. Measure the intake manifold vacuum while idling (no load) using the vacuum gauge. (See INTAKE MANIFOLD VACUUM INSPECTION [LF].)

Electronic Throttle Control System Inspection

Engine coolant temperature compensation inspection
1. Connect the M-MDS to the DLC-2.
2. Access the following PIDs:
3. Verify that the engine is cold, then start the engine.
4. Verify that the engine speed decreases as the engine warms up.
Load compensation inspection
1. Start the engine and idle it.
2. Connect the M-MDS to the DLC-2.
3. Verify that P0506, P0507, or P0511 is not displayed.
4. Access the RPM PID.

NOTE:

5. Verify that the engine speed is within the specification under each load condition. (See ENGINE TUNE-UP [LF].)
Throttle position (TP) sweep inspection
1. Connect the M-MDS to the DLC-2.
2. Turn the ignition switch to the ON position.
3. Verify that none of the following DTC are displayed:
4. Access TP_REL PID.
5. Verify that the PID reading is within the CTP value. (See PCM INSPECTION [LF].)
6. Gradually depress the throttle pedal and verify that the PID reading increases accordingly.
7. Fully depress the throttle pedal and verify that the PID reading is within WOT value. (See PCM INSPECTION [LF].)

Variable Intake air Control Operation Inspection

1. Start the engine.
2. Inspect the rod operation. (See VARIABLE INTAKE AIR SHUTTER VALVE ACTUATOR INSPECTION [LF].)
a. Stop the engine.
b. Connect the M-MDS to the DLC-2.
c. Verify that DTC P0661 or P0662 is not displayed.

  • If DTC P0661 or P0662 is shown, perform DTC inspection.

    (See DTC TABLE [LF].)

d. Inspect the variable intake air solenoid valve. (See VARIABLE INTAKE AIR SOLENOID VALVE INSPECTION [LF].)

Variable Tumble Control Operation Inspection

1. Connect the M-MDS to the DLC-2.
2. Access ECT PID.
3. Verify that ECT PID is below 60 °C {140 °F}.
4. Start the engine.
5. Inspect rod operation under the following conditions: Rod operation

Accelerator pedal position

Release

Depress

Shutter valve actuator

Operate

Not operate

a. Verify that DTC No. P2004, P2006, P2009 or P2010 is not displayed.

  • If DTC No. P2004, P2006, P2009 or P2010 are shown, perform DTC inspection.

    (See DTC TABLE [LF].)

b. Inspect the variable tumble solenoid valve. (See VARIABLE TUMBLE SOLENOID VALVE INSPECTION [LF].)

Fuel Injector Operation Inspection

If simulation function of M-MDS is used:

STEP

INSPECTION

RESULTS

ACTION

1

Start the engine and warm it up until normal operating temperature.

Connect the M-MDS to DLC-2.

Select the INJ_1, INJ_2, INJ_3, and INJ_4 PIDs

Turn the fuel injector from on to off using the PIDs for each cylinder.

Does the engine speed drop?

Yes

Fuel injector work properly.

No

Engine speed does not drop any cylinders:

Go to the next step.

Engine speed drop some cylinders:

Go to Step 3.

2

Perform main relay operation inspection.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF].)

Does the main relay work properly?

Yes

Go to the next step.

No

Repair or replace malfunctioning parts.

3

Inspect the fuel injector for suspected cylinder.

(See FUEL INJECTOR INSPECTION [LF].)

Is the fuel injector okay?

Yes

Inspect the following for suspected cylinder:

  • Fuel injector power and/or GND systems related harness and connectors.

No

Replace the fuel injector.

(See FUEL INJECTOR REMOVAL/INSTALLATION [LF].)

4

Perform KOER self-test function using M-MDS.

(See KOEO/KOER SELF TEST [LF].)

Are DTC P0201, P0202, P0203 and/or P0204 present?

Yes

Go to appropriate DTC test.

(See DTC TABLE [LF].)

No

Go to the next step.

5

Inspect the fuel injector for suspected cylinder.

(See FUEL INJECTOR INSPECTION [LF].)

Is the fuel injector okay?

Yes

Inspect the following for suspected cylinder:

  • PCM terminals (pulled-out pins, corrosion)

  • Fuel injector terminals (pulled-out pins, corrosion)

No

Replace the fuel injector.

(See FUEL INJECTOR REMOVAL/INSTALLATION [LF].)

If simulation function of M-MDS is not used:

STEP

INSPECTION

RESULTS

ACTION

1

While cranking the engine, inspect for fuel injector operation sound at each cylinder using a soundscope.

Is operation sound heard?

Yes

Fuel injector operation is normal.

No

All cylinders not heard:

Go to the next step.

Some cylinders not heard:

Go to Step 3.

2

Perform main relay operation inspection.

Is main relay operation normal?

Yes

Inspect the following:

  • Fuel injector power system related wiring harness and connectors

  • PCM connectors

  • Fuel injector GND and related wiring harness and connectors

No

Repair or replace malfunctioning parts.

3

Switch fuel injector connector of not operating fuel injector with operating fuel injector.

Is operation sound heard?

Yes

Go to the next step.

No

Replace the fuel injector.

4

Are wiring harness and connectors of not operation fuel injector normal? (Open or short)

Yes

Inspect PCM terminal voltage of fuel injector signal.

No

Repair or replace malfunctioning parts.

Fuel Cut Control System Inspection

NOTE:

If simulation function of M-MDS is used:
1. Warm up the engine and idle it.
2. Connect the M-MDS to DLC-2.
3. Select the RPM and FUELPW1 PIDs.
4. Monitor the both PIDs while performing the following steps.
a. Depress the accelerator pedal and increase the RPM PID to 4,000 rpm.
b. 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 simulation function of M-MDS is not used:
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.
a. Depress the accelerator pedal and increase the engine speed to 4,000 rpm.
b. 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].)

Fuel Pump Operation Inspection

1. Remove the fuel-filler cap.
2. Turn the ignition switch to the ON position.
3. Turn the fuel pump relay from off to on using the FP PID and inspect if the operation sound is heard.
4. Measure voltage at wiring harness side fuel pump connector terminal B.

Fuel Pump Control System Inspection

1. Crank the engine and verify that fuel pump relay operation sound is heard.
2. If operation sound is not heard, inspect the following:

Spark Test

1. Disconnect the fuel pump relay.
2. Verify that each ignition coil and connector is connected properly.
3. Inspect the ignition system in the following procedure.

WARNING:



STEP

INSPECTION

ACTION

1

  • Disconnect the ignition coil from spark plugs.

  • Remove the spark plugs.

    • Verify that the spark plugs do not have carbon deposits.

  • Are the spark plugs normal?

Yes

Go to the next step.

No

Perform no-load racing at 4,000 rpm for 2 min, 2 times to burn off the carbon deposits.

Repeat Step 1.

2

  • Inspect the spark plugs for damage, wear, and proper plug gap.

  • Are the spark plugs normal?

Yes

Go to the next step.

No

Replace spark plugs, then go to the next step.

3

  • Reconnect the spark plugs to the ignition coil.

  • Ground the spark plugs to the engine.

  • Is a strong blue spark visible at each cylinder while cranking the engine?

Yes

Ignition system is normal.

No
    Some cylinders do not spark:

  • Go to the next step.

    All cylinders do not spark:

  • Go to Step 5.

4

  • Inspect the following wiring harnesses for open or short:

    • Ignition coil No.1 terminal C—PCM terminal 2BA

    • Ignition coil No.2 terminal C—PCM terminal 2AW

    • Ignition coil No.3 terminal C—PCM terminal 2AX

    • Ignition coil No.4 terminal C—PCM terminal 2AT

  • Are the wiring harnesses normal?

Yes

Inspect and replace the ignition coil.

(See IGNITION COIL INSPECTION [LF].)

No

Repair or replace the malfunctioning part, then go to Step 1.

5

  • Measure the voltage at terminal A in each ignition coils.

  • Is the voltage B+?

Yes

Go to the next step.

No

Inspect power supply circuit of ignition coils.

6

Verify continuity between each ignition coils terminal B and battery negative post.

Is there any continuity?

Yes

Go to the next step.

No

Inspect GND circuit of ignition coils.

7

  • Does the PCM connector or ignition coil connectors have poor connection?

Yes

Repair or replace the connector, then go to Step 1.

No

Go to the next step.

8

  • Are the following parts normal?

    • CKP sensor and crankshaft pulley

Yes

Inspect for open or short circuit in wiring harness and connector of CKP sensor.

No

Repair or replace the malfunctioning part, then go to Step 1.

EGR Control System Inspection

If simulation function of M-MDS is used:
1. Crank the engine and verify that EGR valve operation (initial operation) sound is heard.
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.
a. Stop the engine.
b. Remove the EGR valve.
c. Connect the EGR valve connector.
d. Turn the ignition switch to the ON position.
e. Increase the step value of EGR valve from 0 to 52 using SEGRP PID.
f. 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.
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.
10. Stop the vehicle and verify that the SEGRP value is returned to 0.
If simulation function of M-MDS is not used:
1. Crank the engine and verify that EGR valve operation (initial operation) sound is heard.
2. Start the engine and idle it.
3. Warm up the engine to normal operating temperature.
4. Access the following PIDs:
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.
8. Stop the vehicle and verify that the SEGRP value returns to 0.

Purge Control System Inspection

If simulation function of M-MDS is used:
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.
4. Connect the M-MDS to the DLC-2 and verify that the DTC P0443 is shown. Perform the DTC inspection.

(See DTC TABLE [LF].)

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.
7. Warm up the engine to normal operating temperature.
8. Monitor the EVAPCP PID using the M-MDS, and drive the vehicle approx. 2,000 rpm for 30 sec. or more.
If simulation function of M-MDS is not used:
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.
4. Connect the M-MDS to the DLC-2 and verify that the DTC P0443 is shown. Perform the DTC inspection.

(See DTC TABLE [LF].)

5. Access EVAPCP and ECT PIDs.
6. Verify that the ECT PID is more than 78 °C {173 °F}.
7. Set the vehicle on the dynamometer or chassis roller.

WARNING:

8. Drive the vehicle approx. 2,000 rpm for 30 sec. or more.

A/C Cut-off Control System Inspection

1. Start the engine.
2. Turn the A/C switch and the fan switch on.
3. Verify that the A/C compressor magnetic clutch actuates.
4. Fully open the throttle valve and verify that the A/C compressor magnetic clutch does not actuate for 2—5 s.

Cooling Fan Control System Inspection

If simulation function of M-MDS is used:
1. Connect the M-MDS to DLC-2.
2. Start the engine and warm it up to normal operating temperature.
3. Perf Verify that the DTC P0480, P0481 or P0482 is not shown and cooling fan operating while the KOER self-test.orm the KOER self-test. (See KOEO/KOER SELF TEST [LF].)
4. Verify that the DTC P0480, P0481 or P0482 is not shown and cooling fan operating while the KOER self-test.
a. Inspect the cooling fan motor and wiring harness between cooling fan motor and GND.
b. Select FAN1, FAN2 and FAN3 PIDs.
c. Turn ignition switch off and disconnect the cooling fan motor connector.
d. 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.

If simulation function of M-MDS is not used:
1. Connect the M-MDS 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].)
4. Verify that the DTC P0480, P0481 or P0482 is not shown and cooling fan operating while the KOER self-test.
a. Inspect the cooling fan motor and wiring harness between cooling fan motor and GND.
b. Turn the ignition switch to off.
c. Disconnect ECT sensor connector.
d. 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.

e. Turn the ignition switch off and disconnect the ECT sensor connector.
f. Reconnect the ECT sensor and clear the DTC from PCM memory using the M-MDS.

Variable Valve Timing Control System Operation Inspection

If simulation function of M-MDS is used:
1. Warm up the engine to normal operating temperature.
2. Connect the M-MDS 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.
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.
10. If they are okay, replace the intake camshaft pulley (with a built-in variable valve timing actuator).
If simulation function of M-MDS is not used:
1. Start the engine and run it at idle.
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.
6. Inspect the variable valve timing actuator. (See VARIABLE VALVE TIMING ACTUATOR INSPECTION [LF].)
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.
10. Remove the oil control valve (OCV) and perform spool valve operation inspection.

(See OIL CONTROL VALVE (OCV) INSPECTION [LF].)

11. If they are normal, replace the camshaft pulley (with built-in variable valve timing actuator).

Evaporative Emission (EVAP) System Leak Inspection

EVAP system leak inspection using M-MDS

NOTE:



DTC No.

Condition

P0442

Evaporative emission control system leak detected (small leak)

P0446

Change over valve (COV) (EVP system leak detection pump) stuck close

P0455

Evaporative emission control system leak detected (gross leak)

P0456

Evaporative emission system leak detected (very small leak)

P2401

EVAP system leak detection pump motor circuit low

P2402

EVAP system leak detection pump motor circuit high

P2404

EVAP system leak detection pump sense circuit problem

P2405

EVAP system leak detection pump sense circuit low input

P2407

EVAP system leak detection pump sense circuit intermittent

Evaporative system test procedure
1. Select the EVAP system test from the Toolbox on the M-MDS display and follow the instructions.
2. Verify that all of the following PIDs are within the specifications at the pre-test confirmation screen.

NOTE:

Specification

PID

PID Range

BARO

72.2 kPa {543 mmHg, 21.3 inHg} or more

FLI

15—85%

IAT

5—45 °C {41—113 °F}

VPWR

11.0 V or more

3. Start the engine.
4. Drive the vehicle or let the engine idle more than 20 min.
5. Turn ignition switch off, then turn it to the ON position again (Key On Engine Off).
6. Press the tick icon to start the test.
7. Verify that no DTCs present after the completion of the test.
EVAP system leak inspection using leak tester
1. Perform the following SST (EVAP System Tester 134-01049) self-test:

NOTE:

a. Verify that the control valve on the panel is in the HOLD position then open the nitrogen bottle valve.

b. Connect the vehicle interface hose (part of the SST) to the SELF-TEST port located on the control panel. Hand tighten the fitting. (Do not overtighten.)
c. Turn the control valve to the TEST position.
d. The gauge should read 331—381 mm {13—15 in} of water.

  • If the gauge is not reading in this range, adjust the pressure by turning the black knob on the low pressure regulator at the nitrogen bottle.

e. Turn the control valve to the HOLD position.
f. Verify that the gauge holds pressure and that the flow meter reads no flow.

  1. If there is no drop in pressure and no flow, the tester passes the self-test.

  2. If the gauge leaks down, refer to the tester operators manual.

2. Connect the SST to the vehicle.
a. Verify that the control valve on the panel is in the HOLD position then open the nitrogen bottle valve.
b. Remove the fuel-filler cap from the vehicle.

  • If the fuel-filler cap is not a MAZDA part or equivalent, replace it.

c. Connect the receiver assembly (SST: AKS441130) to the vehicle cap test hose assembly (part of the SST) and the fuel-filler cap from the vehicle.

d. Connect the cap adaptor (SST: AKS441131) to the vehicle cap test hose assembly (part of the SST) and to the fuel-filler neck.
e. Connect the vehicle interface hose (part of the SST) to the center fitting of the vehicle cap test hose assembly (part of the SST).
3. Connect the M-MDS to the DLC-2.
4. Turn the ignition switch to the ON position (Engine off).
5. Request the PCM on-board device control (Mode 08) using the M-MDS to close the change-over valve (COV) in the EVAP system leak detection pump.

NOTE:

6. Make sure the control valve on the 134-01049 is in the HOLD position and that the valve on the cylinder of nitrogen gas is open.
7. Turn the control valve to the open position and let the system fill. You should note a drop in the gauge pressure along with the flow meter being pegged at maximum flow for several minutes depending on how full or empty the fuel tank is, and how long it takes to completely fill and pressurize the evaporative emissions system hoses.
8. If the gauge and the flow meter do not settle to a measurable level after 2—3 min, then refer to the Mazda Workshop Manual to verify that the cut or vent valve is properly closed.
9. Verify the pressure gauge and flow meter reading to determine if there is an evaporative emissions leak:

NOTE:

  1. Turn the control valve to the HOLD position then disconnect the SST.



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