Evaporative Emission (Evap) System Leak Inspection - Mazda CX-7 2007 Workshop Manual

SYMPTOM TROUBLESHOOTING [L3 WITH TC]
When idling can be continued
If simulation function of M-MDS is used:
1. Warm up the engine to normal operating temperature.
2. Connect the M-MDS to the DLC-2.
3. Start the engine and run it is idling.
4. Select the 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) while the 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 circuit (Oil control valve (OCV) —PCM terminal 2AF)
10. If they are normal, replace the intake camshaft pulley (with a built-in variable valve timing actuator).
If simulation function of M-MDS is not used:
1. Disconnect the oil control valve (OCV) connector.
2. Warm up the engine and idle it.
3. 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.
4. Remove the oil control valve (OCV) and perform the spool valve operation inspection.
(See01-10-29 OIL CONTROL VALVE (OCV) INSPECTION[L3 WITH TC].)
• If not as specified, inspect the following:
— Oil control valve (OCV)
— Harnesses and connectors between oil control valve (OCV) and PCM have an open or short circuit.
• 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
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 the 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:
i. The PCM turns the air pump on and retrieves the air pump load current value (LDP_MON PID) as a
reference current (LDP_REF PID).
ii. After retrieving the reference current value, the PCM commands the change-over-valve to open, then
captures the air pump load current value (LDP_MON PID) as the idle current (LDP_IDL PID). The
EVAP system will be pressurized from this phase.
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