Mazda CX 7. Manual - part 98

SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–89

01-03

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 
contact or be caught up in any of the rotating parts.

11. Drive vehicle at an engine speed to 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 during Step 2.

• If there is no vacuum, inspect the following:

— Wiring harness and connector (Main relay—purge solenoid valve—PCM terminal 2AB)

— 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 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 ground circuit in the 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. Connect the M-MDS to the DLC-2.
2. Start the engine and warm it up to normal operating temperature.
3. Perform the KOER self-test.

(See01-02-10 KOEO/KOER SELF TEST[L3 WITH TC].)

4. Verify that the DTC P0480 is not shown and the cooling fan operates during the KOER self-test.

• If DTC P0480 is shown, perform the DTC troubleshooting procedure.

(See01-02-152 DTC P0480[L3 WITH TC].)

• If the cooling fans do not operate, proceed to the following:

(1) Verify the clicking sound of the cooling fan relay when the ignition switch is turned from the off to the ON 

position.

(2) If there is no the clicking sound, inspect the cooling fan relay for an open circuit between the ignition switch 

and the cooling fan relay.

• If there is a clicking sound, go to the next step.

• Inspect the following parts in the indicated order in accordance with fan operation conditions.

Cooling fans do not operate

— Open circuit between the fan control module and the cooling fan relay

— Open circuit between fan control module and ground

— Poor connection of the fan control module connector

— Fan control module

(See01-12-14 FAN CONTROL MODULE INSPECTION[L3 WITH TC].)

Cooling fan motor No.1 does not operate

— Open or short to ground circuit between the fan control module and cooling fan motor No.1

— Poor connection of the fan control module connector or cooling fan motor No.1 connector

— Cooling fan motor No.1

(See01-12-14 FAN MOTOR INSPECTION[L3 WITH TC].)

— Fan control module

(See01-12-14 FAN CONTROL MODULE INSPECTION[L3 WITH TC].)

Cooling fan motor No.2 does not operate

— Open or short to ground circuit between the fan control module and the cooling fan motor No.2

— Poor connection of the fan control module connector or the cooling fan motor No.1 connector

— Cooling fan motor No.2

(See01-12-14 FAN MOTOR INSPECTION[L3 WITH TC].)

— Fan control module

(See01-12-14 FAN CONTROL MODULE INSPECTION[L3 WITH TC].)

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SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–90

Wastegate Control System Operation Inspection
If simulation function of M-MDS is used:

1. Start the engine and run it is idling.
2. Disconnect the hose between the wastegate control solenoid valve and the intake pipe.
3. Put a finger to the wastegate control solenoid valve and verify that there is no pressure applied.

• If there is pressure, inspect the following:

— Wiring harness and connectors (Wastegate control solenoid valve— PCM terminal 2AA)

— Wastegate control solenoid valve (Stuck open)

4. Warm up the engine to normal operating temperature.
5. Connect the M-MDS to the DLC-2 and verify that DTC P0245 or P0246 are shown. Perform the DTC 

inspection.
(See01-02-112 DTC P0245[L3 WITH TC].)
(See01-02-114 DTC P0246[L3 WITH TC].)

6. Select the VGT PID.
7. Increase the duty value of the wastegate control solenoid valve and inspect if the operation sound of the 

solenoid valve is heard.

• If the operation sound is heard, inspect for loose or damaged vacuum hoses. (Wastegate actuator—

wastegate control solenoid valve—intake hose)

• If the operation sound is not heard, perform the wastegate control solenoid valve inspection.

(See01-13-14 WASTEGATE CONTROL SOLENOID VALVE INSPECTION[L3 WITH TC].)

8. Warm up the engine to normal operating temperature.
9. Monitor the VGT and APP PIDs using the M-MDS.

10. Run the engine with the APP PID above 30% and verify that the VGT PID value increases from 0%.

• If the VGT PID is 0%, inspect the APP PID.

If simulation function of M-MDS is not used:

1. Start the engine and run it is idling.
2. Disconnect the hose between the wastegate control solenoid valve and the intake pipe.
3. Put a finger to the wastegate control solenoid valve and verify that there is no pressure applied.

• If there is pressure, inspect the following:

— Wiring harness and connectors (Wastegate control solenoid valve—PCM terminal 2AA)

— Wastegate control solenoid valve (Stuck open)

4. Warm up the engine to normal operating temperature.
5. Connect the M-MDS to the DLC-2 and verify that the DTC P0245 or P0246 are shown. Perform the DTC 

inspection.
(See01-02-112 DTC P0245[L3 WITH TC].)
(See01-02-114 DTC P0246[L3 WITH TC].)

6. Warm up the engine to normal operating temperature.
7. Monitor the VGT and APP PIDs using the M-MDS.
8. The hose between the wastegate control solenoid valve and intake pipe is disconnected.
9. Run the engine with the APP PID above 30% and verify that the VGT PID value increases from 0% and there 

is pressure applied.

• If the VGT PID is 0%, inspect the TP_REL PID.

• If there is no pressure applied, inspect for the following:

— Wastegate control solenoid valve (Stuck closed)

— Hose connection (Intake hose (turbocharger compressor downstream side) —wastegate actuator—

intake hose (turbocharger compressor upstream side))

Variable Valve Timing Control System Operation Inspection
When idling cannot be continued

1. Remove the oil control valve (OCV) and verify that the spool valve is at maximum retard position.
2. Connect the oil control valve (OCV).
3. Turn the ignition switch to the ON position.
4. Verify that the spool valve is at the 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.

5. Inspect the variable timing actuator.

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SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–91

01-03

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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SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–92

iii. 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 EVAP gas leak 

has occurred or not by reading the test 
results.

EVAP system malfunction judgment

• The PCM calculates the stored air pump load current value and sends the results to the M-MDS as DTCs:

CHANGE-
OVER-VALVE

LOAD 
CURRENT 
(LDP-MON)

 (LDP-IDL)

 (LDP-REF)

 FAIL

 PASS

OFF

ON

CLOSED

OPEN

AIR-PUMP

acxuuw00000321

FUEL TANK

INTAKE 
MANIFOID

CANISTER

PURGE-VALVE

CHANGE-OVER-VALVE

ORIFICE

AIR-PUMP

AIR FILTER

AIR

EVAPORATIVE EMISSION 
SYSTEM LEAK DETECTION 
PUMP

P

acxuuw00000322

DTC No.

Condition

P0442

EVAP control system leak detected (small leak)

P0446

Change over valve (COV) (EVAP system leak detection pump) stuck closed

P0455

EVAP control system leak detected (gross leak)

P0456

EVAP control 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 sensor circuit malfunction

P2405

EVAP system leak detection pump sensor circuit low input

P2407

EVAP system leak detection pump sensor circuit intermittent

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