Part 2
ENGINE CONTROL SYSTEM OPERATION INSPECTION [L3]
Part 2
Continued From Part 1 Part 1
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:
- Fuel pump relay
Testing and Inspection
- Wiring harness and connectors (Main relay - fuel pump relay - PCM terminal 1BG)
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:
- High voltage in the ignition system can cause strong electrical shock which can result in serious injury. Avoid direct contact to the vehicle body during the following spark test.
Step 1-Step 8:
EGR Control System Inspection
1. Crank the engine and verify that EGR valve operation (initial operation) sound is heard.
- If the operation sound is not heard, connect the M-MDS to the DLC-2 and verify that the DTC P0403 is shown. Perform DTC inspection. DTC Table [Engine]
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.
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.
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 REL and ECT PIDs. Component Tests and General Diagnostics
8. Stop the vehicle and verify that the SEGRP value returns to 0.
Purge Control System Inspection
1. Start the engine.
2. Disconnect the vacuum hose between the purge solenoid valve and the charcoal canister.
3. Put a 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 valve
4. Warm up the engine to the normal operating temperature.
5. Stop the engine.
6. Connect the M-MDS to the DLC-2 and verify that the DTC P0443 is shown. Perform DTC inspection. DTC Table [Engine]
7. Turn the ignition switch to the ON position.
8. Access ECT PID.
9. Verify that the engine coolant temperature is more than 78 °C {172 °F}.
- If the M-MDS indicates less than 78 °C {172 °F}, perform the ECT sensor inspection.
10. 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 be caught up in any of the rotating parts.
11. Drive vehicle at engine speed approx. 2000 rpm for 30 s or more.
12. Put a finger to the purge solenoid valve and verify that there is no vacuum applied while step 2.
- 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 REL and LOAD PIDs
- If there is vacuum, inspect the following:
- Vacuum hose (Purge solenoid valve - charcoal canister)
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.
- If it does not actuate, go to symptom troubleshooting "No.23 A/C does not work sufficiently".
4. Fully open the throttle valve and verify that the A/C compressor magnetic clutch does not actuate for 2-5 s.
- If it actuates, inspect as follows:
- A/C relay
- Open or short to GND circuit in wiring harness and connectors (Ignition switch-A/C relay-PCM terminal 1I)
- A/C related parts
- APP1, APP2 PIDs
Cooling Fan Control System Inspection
1. Verify that the battery voltage is more than 12.4 V.
- If the battery voltage is less than 12.4 V, charge the battery or connect the external power supply.
2. Connect the M-MDS and access ECT PID.
3. Turn A/C switch to off.
4. Verify ECT PID is less than 98 °C {208 °F}.
- If ECT PID more than 98 °C {208 °F}, inspect ECT sensor and related wiring harnesses.
5. Verify that the cooling fan does not operate with ECT PID is less than 98 °C {209 °F} while the ignition switch is ON.
- If the cooling fan operates, inspect for following parts and related wiring harnesses:
- ECT sensor
- A/C switch
- A/C refrigerant pressure switch (High/low pressure)
- A/C refrigerant pressure switch (Medium pressure)
- VSS
- A/C magnetic clutch
- Fan control signal circuit (between fan control module terminal B and PCM terminal 1R)
- If the all items are normal, replace fan control module.
6. Verify the cooling fan operates while the A/C switch to ON with the ignition switch at ON position.
- If the cooling fan does not operate, inspect for following:
- A/C switch
- A/C refrigerant pressure switch (High/low pressure)
- Fan control module power supply circuit
- Fan control module GND circuit
- Fan control signal circuit (between fan control module terminal B and PCM terminal 1R)
- If the all items are normal, replace fan control module.
7. Verify that the cooling fan operates with following table.
*
A/C refrigerant pressure switch (medium pressure) condition
- If the cooling fan operation is not specified, inspect for following:
- A/C refrigerant pressure switch (Medium pressure)
- If the A/C refrigerant pressure switch (Middle pressure) is normal, replace fan control module.
8. Turn A/C switch to off.
9. Start the engine and idle it.
10. Verify that the cooling fan operating speed increases relative to ECT PID increases.
- If the cooling fan speed does not increase inspect following:
- ECT sensor (characteristic)
Testing and Inspection
- Fan control signal circuit (between fan control module terminal B and PCM terminal 1R)
- If the all items are normal, replace fan control module.
Variable Valve Timing Control System Operation Inspection
When idling cannot be continued
1. Remove the OCV and verify that the spool valve is at maximum retard position.
2. Connect the OCV.
3. Turn the ignition switch to the ON position.
4. 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 OCV and the PCM.
5. Inspect the variable valve timing actuator. Testing and Inspection
When idling can be continued
1. Disconnect OCV connector.
2. Warm up the engine and idle it.
3. Apply battery voltage to the 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.
4. Remove the OCV and perform spool valve operation inspection.
Testing and Inspection
- If not as specified, inspect the following:
- OCV
- Harnesses and connectors between OCV and PCM open or short.
- If as specified, inspect the following hydraulic passages for clogging or leakage or both:
- Oil pressure switch - OCV
- OCV - camshaft
- Camshaft internal passage
5. If they are normal, replace the camshaft pulley (with built-in variable valve timing actuator).
Evaporative Emission (EVAP) System Leak Inspection
- To verify that the problem has been fixed properly after repairs, the run drive cycle or EVAP system leak inspection must be performed.
EVAP system leak inspection using M-MDS
NOTE:
EVAP system test outline
- The EVAP system test, which can substituted for the run drive cycle as an EVAP control system repair confirmation method, can be done while operating the M-MDS in the KOEO (Key On Engine Off) condition instead of actually driving the vehicle.
EVAP system test description
- The EVAP system test finds gas leaks in the system using the PCM to monitor changes in the air pump load current of the EVAP system leak detection pump. This test starts after sending an on-demand test signal from the M-MDS to the PCM. The PCM controls the air pump and change-over-valve operation and also stores the load current of the air pump as follows:
- The PCM commands turn the air pump on and retrieve the air pump load current value (LDP_MON PID) as a reference current (LDP_REF PID).
- After retrieving a reference current value, the PCM commands the change-over-valve to open, then captures the air pump load current value (LDP_MON PID) as idle current (LDP_IDL PID). The EVAP system will be pressurized from this phase.
- The PCM continues to monitor the air pump load current value (LDP_MON PID) until the end of the test.
- You can confirm whether any evaporative gas leak occurred or not by reading the test results.
EVAP system malfunction judgment
- The PCM calculates the stored air pump load current value and send the results to the M-MDS as DTCs:
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:
- To successfully perform this procedure, all PIDs must be within the following specifications before proceeding to the next step.
- The PCM will cancel the EVAP system test if the VPWR PID value falls lower than 11.0 V during the test.
Specification
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.
- If any test result is indicated with red, diagnose the problem using the following DTC troubleshooting procedure or component inspection procedure.
- If any DTCs are detected, diagnose the problem using the appropriate DTC troubleshooting procedure.
EVAP system leak inspection using leak tester
1. Perform the following SST (EVAP System Tester 134-01049) self-test:
NOTE:
- If the tester does not work correctly during the self-test, refer to the tester operators manual for a more detailed self-test procedure.
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 to the vehicle cap test hose assembly (part of the SST) and the fuel-filler cap from the vehicle.
d. Connect the cap adaptor to the vehicle cap test hose assembly (part of the SST) and to the fuel-filler neck.
e. Connect the vehicle interface hose to the center fitting of the vehicle cap test hose assembly.
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:
- The COV is closed for 10 min unless the following any actions are done:
- The engine is started.
- The ignition switch is turned off position.
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 appropriate service information 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:
NO EVAPORATIVE LEAK:
- The flow meter registers "zero flow" and the pressure gauge returns to the pre-set pressure of 356 mm {14 in} of water (H2O).
EVAPORATIVE LEAK:
- The pressure does not return to the preset level of 356 mm {14 in} of water (H2O) when measuring the flow. See "SETTING LEAK STANDARD FOR TESTING" (.020 to.040 inch H2O) of the Evaporative Emissions Tester operators manual (134-01067).
NOTE:
1 Turn the control valve to the HOLD position then disconnect the SST.