Engine Control System: Diagnosis Mazda CX-7 I facelift

PCM inspection preparation

1. Disconnect the negative battery cable.
2. Remove the battery and battery tray. (See «BATTERY REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343783-S22929626792009101500000) ).
3. Remove the windshield wiper arm and blade. (See «WINDSHIELD WIPER ARM AND BLADE REMOVAL/INSTALLATION»(ref-343767-S09185334432009101500000) ).
4. Remove the cowl grille. (See «COWL GRILLE REMOVAL/INSTALLATION»(ref-343791-S10664681202009101500000) ).
5. Remove the windshield wiper motor. (See «WINDSHIELD WASHER MOTOR REMOVAL/INSTALLATION»(ref-343767-S08738785032009101500000) ).
6. Remove the cowl panel. (See «COWL PANEL REMOVAL/INSTALLATION»(ref-343787-S28884932782009101500000) ).
7. Remove the PCM bracket with the PCM connector still connected. (See «PCM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S36886452072009101500000) .)
8. Connect the negative battery cable.

Scheme 5

PCM TERMINAL VOLTAGE TABLE

Scheme 6

POWER STEERING PRESSURE (PSP) SWITCH INSPECTION [L3 WITH TC]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

Continuity Inspection

1. Inspect the following if the power steering is inoperative (See «POWER STEERING FLUID INSPECTION»(ref-343793-S15611318132009101500000) .): Power steering fluid level Power steering fluid leakage Power steering fluid pressure
2. Disconnect the PSP switch connector.
3. Start the engine.
4. Inspect for continuity between the PSP switch terminal and ground using a tester. If not as specified, replace the PSP switch. (See «POWER STEERING OIL PUMP REMOVAL/INSTALLATION»(ref-343793-S40861938122009101500000) ). If the PSP switch is normal, but PID value is out of specification, perform the "Circuit Open/Short Inspection".

Specification

Scheme 7

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Scheme 9

1. Disconnect the PCM connector. (See «PCM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S36886452072009101500000) .)
2. Inspect the following harnesses for an open or short circuit. (Continuity check)

VARIABLE SWIRL SHUTTER VALVE SWITCH INSPECTION [L3 WITH TC]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

Scheme 10

Scheme 11

1. Turn the ignition switch to the ON position (Engine off).
2. Verify that the PCM terminal 2AE voltage is as shown in the following table when the variable swirl shutter valve actuator rod is depressed and released by hand.

1. If not as specified, perform the "Circuit Open/Short Inspection". If there is no open or short circuit, replace the intake manifold. (See «INTAKE AIR SYSTEM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343780-S31334616152009101500000) ).

VARIABLE SWIRL SHUTTER VALVE SWITCH OUTPUT VOLTAGE

Scheme 12

1. Disconnect the PCM connector. (See «PCM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S36886452072009101500000) .)
2. Inspect the following harnesses for an open or short circuit. (Continuity check)

ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [L3 WITH TC]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

ECT Sensor Resistance Inspection

1. Drain the engine coolant. (See «COOLING SYSTEM SERVICE WARNINGS [L3 WITH TC]»(ref-343779-S34361020942009101500000) ).
2. Remove the ECT sensor (located above the starter).
3. Place the ECT sensor in water with a thermometer, and heat the water gradually.
4. Measure the resistance between the ECT sensor terminals A and B using a tester. If not as specified, replace the ECT sensor. If the ECT sensor is normal, but PID value is out of specification, perform the "Circuit Open/Short Inspection".

WATER TEMPERATURE AND RESISTANCE SPECIFICATION

Scheme 13

Scheme 14

1. Disconnect the PCM connector. (See «PCM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S36886452072009101500000) .)
2. Inspect the following wiring harnesses for an open or short circuit. (Continuity check)

Visual Inspection

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

1. Visually inspect for the following on the MAF sensor. (See «INTAKE AIR SYSTEM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343780-S31334616152009101500000) ). Damage Cracks Bent terminals Terminal rust If any of the above are found, replace the MAF/IAT sensor. If the monitor item status/specification (reference) is not within the specification even though there is no malfunction, perform the "Circuit Open/Short Inspection".

Voltage Inspection

1. Remove the MAF/IAT sensor without disconnect the MAF/IAT sensor connector.
2. Turn the ignition switch to the ON position.
3. As the air gradually approaches the MAF detection part of the MAF/IAT sensor, verify that the voltage at PCM terminal 1AK (M-MDS PID: MAF) varies. If it cannot be verified even though the related harnesses have no malfunction, replace the MAF/IAT sensor.

Scheme 15

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Scheme 17

1. Disconnect the PCM connector. (See «PCM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S36886452072009101500000) .)
2. Disconnect the MAF/IAT sensor connector.
3. Inspect the following wiring harnesses for an open or short circuit. (Continuity check)

Resistance Inspection

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

1. Disconnect the MAF/IAT sensor.
2. Measure the resistance between the MAF/IAT sensor terminals D and E using a tester. If not as specified, replace the MAF/IAT sensor. (See «INTAKE AIR SYSTEM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343780-S31334616152009101500000) ). If the MAF/IAT sensor is normal, but the PID is out of specification, perform the "Circuit Open/Short Inspection".

AMBIENT TEMPERATURE AND RESISTANCE SPECIFICATION

Scheme 18

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Scheme 20

1. Disconnect the PCM connector. (See «PCM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S36886452072009101500000) .)
2. Inspect the following wiring harnesses for an open or short circuit. (Continuity check)

MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR INSPECTION [L3 WITH TC]

Note. Perform the following inspection only when directed. The following vacuum values are indicated by relative pressure from the MAP sensor.

1. Connect the M-MDS to the DLC-2.
2. Turn the ignition switch to ON (Engine off).
3. Select MAP PID on the M-MDS.
4. Verify that the MAP PID (pressure) and barometric pressure are practically equal. If not as verified, perform the "Circuit Open/Short Inspection". If there is no open or short circuit, replace the MAP sensor. If as verified, go to next step.
5. Apply vacuum of -25.0 kPa {-187 mmHg, -7.38 inHg} to the MAP sensor, and verify that the MAP variation from that of Step 4 is approx. 25.0 kPa {187 mmHg, 7.38 inHg}. If not as verified, perform the "Circuit Open/Short inspection". If there is no open or short circuit, replace the barometric pressure sensor. (See «INTAKE AIR SYSTEM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343780-S31334616152009101500000) ).

Scheme 21

Scheme 22

1. Disconnect the PCM connector. (See «PCM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S36886452072009101500000) .)
2. Inspect the following wiring harnesses for an open or short circuit. (Continuity check)

BAROMETRIC PRESSURE (BARO) SENSOR INSPECTION (L3 WITH TC)

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

1. Connect the M-MDS to the DLC-2.
2. Turn the ignition switch to the ON position.
3. Select BARO on the M-MDS.
4. Verify that the BARO PID (pressure) and barometric pressure are practically equal. If not as verified, replace the PCM. (See «PCM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S36886452072009101500000) .)

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

Scheme 23

1. Disconnect MAP/boost air temperature sensor.
2. Measure the resistance between the MAP/boost air temperature sensor terminals A and B using a tester. If not as specified, replace the MAP/boost air temperature sensor. (See «INTAKE AIR SYSTEM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343780-S31334616152009101500000) ). If the MAP/boost air temperature sensor is normal, but PID are out of specification, perform the "Circuit Open/Short Inspection". AMBIENT TEMPERATURE AND RESISTANCE SPECIFICATION Ambient temperature (°C {°F}) Resistance (kilohm) 20 {68} 2.4-2.7 60 {140} 0.59-0.64

Scheme 24

1. Disconnect the PCM connector. (See «PCM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S36886452072009101500000) .)
2. Inspect the following wiring harnesses for an open or short circuit. (Continuity check)

THROTTLE POSITION (TP) SENSOR INSPECTION [L3 WITH TC]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

Scheme 25

1. Verify that no DTC related to the APP sensor has been detected. If any DTCs related to the APP sensor have been detected, perform the DTC inspection. (See «DTC TABLE [L3 WITH TC]»(ref-343763-S21425878652009101500000) ).
2. Connect the M-MDS to the DLC-2.
3. Start the engine and warm it up (ECT: more than 80°C {176 °F}).
4. Verify that the voltage (M-MDS PID: TP1, TP2) changes according the engine racing. If not as verified, perform the "Circuit Open/Short Inspection". If there is no open or short circuit, replace the throttle body. (See «INTAKE AIR SYSTEM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343780-S31334616152009101500000) .)

Scheme 26

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Scheme 28

1. Disconnect the PCM connector. (See «PCM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S36886452072009101500000) .)
2. Inspect the following wiring harnesses for an open or short circuit. (Continuity check)

ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [L3 WITH TC]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

Scheme 29

1. Turn the ignition switch to the ON position (Engine off).
2. Verify that the PCM terminal 1Y and 1AC change smoothly while throttle valve is gradually opened. If as verified, go to next step. If not as verified, perform the "Circuit Open/Short Inspection". If there is no open or short circuit, replace the throttle body. (See «INTAKE AIR SYSTEM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343780-S31334616152009101500000) ).
3. Verify that the PCM terminal 1Y and 1AC voltages are as shown in the following table. If the voltage is not according to the following table, perform the "Circuit Open/Short Inspection". If there is no open or short circuit, replace accelerator pedal. (See «ACCELERATOR PEDAL REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343780-S12864234142009101500000) ).

APP SENSOR OUTPUT VOLTAGE SPECIFICATION

Scheme 30

Scheme 31

1. Disconnect the PCM connector. (See «PCM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S36886452072009101500000) .)
2. Inspect the following wiring harnesses for an open or short circuit. (Continuity check)

FUEL PRESSURE SENSOR INSPECTION [L3 WITH TC]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

1. Connect the M-MDS to the DLC-2.
2. Turn the ignition switch to the ON position (Engine off).
3. Select the FUEL_PRES PID on the M-MDS.
4. After warming up the engine, verify that the FUEL_PRES PID is at the standard value under the following conditions. If not as verified, replace the fuel delivery pipe. FUEL_PRES PID VALUE Step Condition FUEL_PRES PID 1 Idle 90 s after engine is started Approx. 3 MPa 2 Idle Spill valve solenoid valve connector is disconnected Approx. 530 kPa
5. After connecting the spill valve control solenoid valve connector, clear the DTC.

Scheme 32

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1. Disconnect the PCM connector. (See «PCM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S36886452072009101500000) .)
2. Inspect the following wiring harnesses for an open or short circuit. (Continuity check)

AIR FUEL RATIO (A/F) SENSOR, HEATED OXYGEN SENSOR (HO2S) INSPECTION [L3 WITH TC]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

Scheme 34

1. Warm up the engine to normal operating temperature.
2. Using the M-MDS, monitor the following: Vehicle speed (PID: VSS) Engine speed (PID: RPM) A/F sensor current (PID: O2S11)
3. Drive the vehicle and decelerate the engine speed by releasing the accelerator pedal fully when the engine speed is 3,000 rpm or more .
4. Verify that the A/F sensor current (PID: O2S11) is 0.25 mA or more while decelerating as shown in the figure. If not within the specification, inspect the A/F sensor for an open or short circuit. (See «A/F SENSOR CIRCUIT OPEN/SHORT INSPECTION»(ref-343775-S01650451082009101500000) ).) Then if there is no malfunction in the wiring harness, replace the A/F sensor.

Scheme 35

1. Disconnect the A/F sensor connector.
2. Measure the resistance between A/F sensor terminals 2B and 2D. If not within the specification, replace the A/F sensor. (See «AIR FUEL RATIO (A/F) SENSOR, HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S41294741122009101500000) .) A/F sensor heater resistance 1-10 ohms

Scheme 36

1. Disconnect the PCM connector.
2. Disconnect the A/F sensor connector.
3. Inspect the following wiring harnesses for an open or short circuit. (Continuity inspection)

Scheme 37

HO2S Heater Resistance Inspection

1. Disconnect the HO2S connector.
2. Measure the HO2S resistance between terminals C and D. If not within the specification, replace the HO2S. HO2S heater resistance 2-50 ohms

Scheme 38

HO2S Heater Circuit Open/Short Inspection

1. Disconnect the PCM connector.
2. Disconnect the HO2S connector.
3. Inspect the following wiring harnesses for an open or short circuit. (Continuity check)

CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [L3 WITH TC]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

Scheme 39

1. Verify that the CKP sensor is securely installed.
2. Using a thickness gauge, measure the air gap between the plate projections at the back of crankshaft pulley and the CKP sensor. If not within the specification, inspect the plate projections for cracks or bending. If there is any malfunction, replace the plate. If the monitor item condition/specification (reference) is not within the specification, even though there is no malfunction, carry out the "Circuit Open/Short Inspection". Air gap 0.5-1.5 mm {0.02-0.05 in}

1. Disconnect the negative battery cable.
2. Remove the CKP sensor. (See «CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S29988514872009101500000) .)
3. Verify that there are no metal shavings on the sensor. If the monitor item condition/specification (reference) is without the specification even though there is no malfunction, carry out the "Circuit Open/Short Inspection".

Scheme 40

1. Idle the engine. CAUTION: Water penetrating the connector will cause sensor malfunction. To prevent this, be careful not to damage the wiring harnesses or the waterproof connector so as to cause water penetration.
2. Measure the output voltage using an oscilloscope. If not within the specification, replace the CKP sensor. If the monitor item condition/specification (reference) is without the specification, even though the voltage is within the specification, carry out the "Circuit Open/Short Inspection".

VOLTAGE SPECIFICATION

Scheme 41

1. Inspect the following wiring harnesses for an open or short circuit. (Continuity check)

CAMSHAFT POSITION (CMP) SENSOR INSPECTION [L3 WITH TC]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

1. Disconnect the negative battery cable.
2. Remove the CMP sensor. (See «CAMSHAFT POSITION (CMP) SENSOR REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S29847308182009101500000) .)
3. Verify that there are no metal shavings on the sensor. If the monitor item condition/specification (reference) is not within the specification even though there is no malfunction, carry out the "Circuit Open/Short Inspection".

Scheme 42

1. Idle the engine. CAUTION: Water penetrating the connector will cause sensor malfunction. To prevent this, be careful not to damage the wiring harnesses or the waterproof connector so as to cause water penetration.
2. Measure the output voltage using an oscilloscope. If not within the specification, replace the CMP sensor. If the monitor item condition/specification (reference) is not within the specification, even though the voltage is within the specification, carry out the "Circuit Open/Short Inspection".

VOLTAGE SPECIFICATION

Scheme 43

1. Inspect the following wiring harnesses for an open or short circuit. (Continuity check)

KNOCK SENSOR (KS) INSPECTION [L3 WITH TC]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

1. Turn the ignition switch to the LOCK position.
2. Disconnect the KS connector.
3. Measure the resistance between KS terminals A and B using a tester. If not as specified, replace the KS. (See «KNOCK SENSOR (KS) REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S12143207262009101500000) .) If the KS is normal, but the PID value is out of specification, perform the "Circuit Open/Short Inspection". Specification Approx. 4.87 megohms

Scheme 44

Scheme 45

1. Disconnect the PCM connector. (See «PCM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S36886452072009101500000) .)
2. Inspect the following wiring harnesses for an open or short circuit. (Continuity check)

BAROMETRIC PRESSURE (BARO) SENSOR INSPECTION [L3 WITH TC]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL ).

Scheme 46

1. Connect the M-MDS to the DLC-2.
2. Turn the ignition switch to the ON position.
3. Select BARO on the M-MDS.
4. Verify that the BARO PID (pressure) and barometric pressure are practically equal. If not as verified, replace the PCM. (See «PCM REMOVAL/INSTALLATION [L3 WITH TC]»(ref-343775-S36886452072009101500000) .)