Engine Control System [MZI-3.7]: Diagnosis Mazda CX-9 I рестайлинг

PCM INSPECTION [MZI-3.7]

PCM inspection preparation

1. Disconnect the negative battery cable.
2. Remove the battery and battery tray. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
3. Remove the windshield wiper arm and blade. (See WINDSHIELD WIPER ARM AND BLADE REMOVAL/INSTALLATION .)
4. Remove the cowl grille. (See COWL GRILLE REMOVAL/INSTALLATION .)
5. Remove the windshield wiper motor. (See WINDSHIELD WASHER MOTOR REMOVAL/INSTALLATION .)
6. Remove the cowl panel. (See «COWL PANEL REMOVAL/INSTALLATION»(ref-663033-S42069854372014101600000) .)
7. Remove the PCM connector still connected.
8. Install the battery and battery tray. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
9. Connect the negative battery cable.

Typical Diagnostic Reference Values

Scheme 6

PID VALUES CHART

PID VALUES CHART

PID VALUES CHART

Continuity Inspection

1. Disconnect the PSP switch connector. (See POWER STEERING OIL PUMP DISASSEMBLY/ASSEMBLY .)
2. Start the engine.
3. Verify no continuity between the PSP switch terminals while rotating the steering wheel. If there is continuity, verify that the power steering oil pump is normal and replace the PSP switch. (See POWER STEERING OIL PUMP DISASSEMBLY/ASSEMBLY .) If the monitor item condition/specification (reference) is not within the specification, even though there is no malfunction, perform the "Circuit Open/Short Inspection".

Scheme 7

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the PSP switch connector
3. Disconnect the PCM connector.
4. Inspect the following wiring harness for open or short. (Continuity inspection)

MASS AIR FLOW (MAF) SENSOR INSPECTION [MZI-3.7]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS SERVICE INFORMATION .) The MAF sensor and IAT sensor cannot be removed as a single unit. When replacing the MAF sensor or IAT sensor, replace it together with the MAF/IAT sensor as a single unit.

Visual Inspection

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the MAF/IAT sensor connector.
3. Remove the MAF/IAT sensor (See «MASS AIR FLOW (MAF)/INTAKE AIR TEMPERATURE (IAT) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S28773844622014101600000) )
4. Verify the following items of the MAF sensor. Damage, cracks Rusted sensor terminal Bent sensor terminal If there is any malfunction, replace the MAF sensor. (See «MASS AIR FLOW (MAF)/INTAKE AIR TEMPERATURE (IAT) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S28773844622014101600000) .)

Scheme 8

1. Remove the MAF sensor with the connector still connected. (See «MASS AIR FLOW (MAF)/INTAKE AIR TEMPERATURE (IAT) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S28773844622014101600000) .)
2. Connect the M-MDS to the DLC-2.
3. Turn the ignition switch to the ON position.
4. Verify that the MAF sensor output voltage (PID: MAF) changes when wind is introduced gradually to the sensor part of the MAF sensor. (See «ON-BOARD DIAGNOSTIC TEST [MZI-3.7]»(ref-663050-S41925731952014101600000) ) If it cannot be verified even though the related harnesses have no malfunction, replace the MAF sensor. (See «MASS AIR FLOW (MAF)/INTAKE AIR TEMPERATURE (IAT) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S28773844622014101600000) .) If the monitor item status/specification (reference) is not within the specification, even though the resistance is within the specification, perform the "Circuit Open/Short Inspection".

Scheme 9

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the MAF/IAT sensor connector.
3. Disconnect the PCM connector.
4. Inspect the following wiring harnesses for open or short. (Continuity inspection)

INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTION [MZI-3.7]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS SERVICE INFORMATION .) The MAF sensor and IAT sensor cannot be removed as a single unit. When replacing the MAF sensor or IAT sensor, replace together with the MAF/IAT sensor as a single unit.

Scheme 10

Scheme 11

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the MAF/IAT sensor connector.
3. Measure the resistance between MAF/IAT sensor terminals A and F. If not within the specification, replace the MAF/IAT sensor. (See «MASS AIR FLOW (MAF)/INTAKE AIR TEMPERATURE (IAT) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S28773844622014101600000) .) If the monitor item status/specification (reference) is not within the specification, even though the resistance is within the specification, perform the "Circuit Open/Short Inspection". IAT sensor resistance IAT SENSOR RESISTANCE CHART IAT (°C {°F}) Resistance (kilohm) 10 {50} Approx. 58.75 20 {68} Approx. 37.30 30 {86} Approx. 24.27 60 {140} Approx. 7.70 IAT sensor characteristics graph (reference)

Scheme 12

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the MAF/IAT sensor connector.
3. Disconnect the PCM connector.
4. Inspect the following wiring harnesses for open or short. (Continuity inspection)

THROTTLE POSITION (TP) SENSOR INSPECTION [MZI-3.7]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS SERVICE INFORMATION .) The TP sensor cannot be removed as a single unit. When replacing the TP sensor, replace it together with the throttle body as a single unit.

Scheme 13

Scheme 14

1. Verify that no DTC related to APP sensor has been detected. (See «ON-BOARD DIAGNOSTIC TEST [MZI-3.7]»(ref-663050-S41925731952014101600000) .) If any DTCs related to APP sensor have been detected, perform the DTC inspection. (See «DTC TABLE [MZI-3.7]»(ref-663050-S00956222322014101600000) .)
2. Connect the M-MDS to the DLC-2.
3. Turn the ignition switch to the ON position.
4. Operate the accelerator pedal and verify that the TP sensor output voltage (PID: TP1, TP2) changes as shown in the following graph. (See «ON-BOARD DIAGNOSTIC TEST [MZI-3.7]»(ref-663050-S41925731952014101600000) .) If not 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 [MZI-3.7]»(ref-663036-S20639303202014101600000) .)

Scheme 15

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the throttle body connector.
3. Disconnect the PCM connector.
4. Inspect the following wiring harnesses for open or short circuit. (Continuity inspection)

ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [MZI-3.7]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS SERVICE INFORMATION .) The APP sensor cannot be removed as a single unit. When replacing the APP sensor, replace it together with the accelerator pedal as a single unit.

Scheme 16

1. Turn the ignition switch to the ON position (Engine OFF).
2. Verify that the PCM terminal 1Y and 1U 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 [MZI-3.7]»(ref-663036-S20639303202014101600000) .)
3. Verify that the PCM terminal 1Y and 1U voltages are as shown in the following table. If voltage is not as following table, perform the "Circuit Open/Short Inspection". If there is no open or short circuit, replace accelerator pedal. (See «ACCELERATOR PEDAL REMOVAL/INSTALLATION [MZI-3.7]»(ref-663036-S42696752502014101600000) .) APP sensor output voltage APP SENSOR OUTPUT VOLTAGE CHART Condition PCM terminal 1Y (APP sensor No. 2) PCM terminal 1U (APP sensor No. 3) Accelerator pedal released Approx. 4.1 V Approx. 1.5 V Accelerator pedal depressed Approx. 1.0 V Approx. 3.9 V

Scheme 17

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the APP sensor
3. Disconnect the PCM connector.
4. Inspect the following wiring harnesses for open or short circuit. (Continuity inspection)

AIR FUEL RATIO (A/F) SENSOR INSPECTION [MZI-3.7]

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

Scheme 18

1. Connect the M-MDS to the DLC-2.
2. Warm up the engine to normal operating temperature.
3. Drive the vehicle.
4. Release the accelerator pedal while the engine speed is at 3,000 rpm or more and verify that the following monitor items fluctuate as shown in the illustration while the vehicle decelerates. (See «ON-BOARD DIAGNOSTIC TEST [MZI-3.7]»(ref-663050-S41925731952014101600000) .) VSS RPM O2S11, O2S21 If not within the specification, replace the A/F sensor. (See «AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S24330976482014101600000) .

Scheme 19

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the A/F sensor connector.
3. Measure the resistance between A/F sensor terminals C and E. If it is not within the specification, replace the A/F sensor. (See «AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S24330976482014101600000) .) If the monitor item status/specification (reference) is not within the specification, even though the resistance is within the specification, perform the "Circuit Open/Short Inspection" A/F sensor heater resistance 1-10 ohms

Scheme 20

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the A/F sensor connector.
3. Disconnect the PCM
4. Inspect the following wiring harness for open or short. (Continuity inspection)

HEATED OXYGEN SENSOR (HO2S) INSPECTION [MZI-3.7]

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

Scheme 21

1. Connect the M-MDS to the DLC-2.
2. Warm up the engine to normal operating temperature.
3. Access the following PIDs using the M-MDS. (See «ON-BOARD DIAGNOSTIC TEST [MZI-3.7]»(ref-663050-S41925731952014101600000) .) VSS (Vehicle speed) RPM (Engine speed) O2S11, O2S21 (HO2S output voltage)
4. Drive the vehicle and decelerate the engine speed by releasing the accelerator pedal fully when the engine speed is 3,000 rpm or more .
5. Verify that the front HO2S outputs a voltage of 0.6 V or more , one time or more, then verify that the front HO2S voltage (PID: O2S11, O2S21) is 0.3 V is or less while decelerating as shown in the illustration. If not within the specification, inspect the front HO2S for an open or short circuit. (See «HEATED OXYGEN SENSOR (HO2S) VOLTAGE INSPECTION»(ref-663049-S14030805012014101600000) .) Then if there is no malfunction in the wiring harness, replace the front HO2S. (See «HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S21525227472014101600000) .)

Scheme 22

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the HO2S connector.
3. Measure the resistance between HO2S terminals A and C. If it is not within the specification, replace the HO2S. (See «HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S21525227472014101600000) .) If the monitor item status/specification (reference) is not within the specification, even though the resistance is within the specification, perform the "Circuit Open/Short Inspection". HO2S heater resistance 2-50 ohms

Scheme 23

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the HO2S connector
3. Disconnect the PCM connector.
4. Inspect the following wiring harness for open or short (continuity check).

CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [MZI-3.7]

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

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Remove the Catalytic Converter (WU-TWC) (LH) for easier access. (See «EXHAUST SYSTEM REMOVAL/INSTALLATION [MZI-3.7]»(ref-663045-S14419216032014101600000) .)
3. Remove the CKP sensor. (See «CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S11918435872014101600000) .)
4. Verify that there are no metal shavings on the CKP sensor. If there is a malfunction, remove any metal shavings that are adhearing.

Scheme 24

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Remove the Catalytic Converter (WU-TWC) (LH) for easier access. (See «EXHAUST SYSTEM REMOVAL/INSTALLATION [MZI-3.7]»(ref-663045-S14419216032014101600000) .)
3. Remove the CKP sensor. (See «CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S11918435872014101600000) .)
4. Measure the resistance between the CKP sensor terminals A and B. If not within the specification, replace the CKP sensor. (See «CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S11918435872014101600000) .) If the monitor item status/specification (reference) is not within the specification, even though the resistance is within the specification, perform the "Circuit Open/Short Inspection". CKP sensor resistance 607-743 ohms

Scheme 25

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Remove the CKP sensor. (See «CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S11918435872014101600000) .)
3. Disconnect the PCM connector.
4. Inspect the following harness for open or short circuit. (Continuity check)

CAMSHAFT POSITION (CMP) SENSOR INSPECTION [MZI-3.7]

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

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Remove the battery. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
3. Remove the resonance chamber and air cleaner assembly for easier access. (See «INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZI-3.7]»(ref-663036-S20639303202014101600000) .)
4. Disconnect the CMP sensor.
5. Remove the CMP sensor. (See «CAMSHAFT POSITION (CMP) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S24203731282014101600000) .)
6. Verify that there are no metal shavings on the CMP sensor. If there is a malfunction, remove any metal shavings that are adhearing.

Resistance Inspection

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the CMP sensor connector.
3. Measure the resistance between the CMP sensor terminals A and B. If not within the specification, replace the CMP sensor. (See «CAMSHAFT POSITION (CMP) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S24203731282014101600000) .) If the monitor item status/specification (reference) is not within the specification, even though the resistance is within the specification, perform the "Circuit Open/Short Inspection". CMP sensor resistance 1,146-1,420 ohms

Scheme 26

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the CMP connector.
3. Disconnect the PCM connector.
4. Inspect the following harness for open or short circuit. (Continuity check)

KNOCK SENSOR (KS) INSPECTION [MZI-3.7]

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

Scheme 27

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the KS connector. (See «KNOCK SENSOR (KS) REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S11236648192014101600000) .)
3. Measure the resistance between the KS terminals. KS: terminals A and B (KS (LH)) KS: terminals C and D (KS (RH)) If not as specified, replace the KS. (See «KNOCK SENSOR (KS) REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S11236648192014101600000) .) If the KS is normal, but PID value is out of specification, perform the "Circuit Open/Short Inspection". KS resistance Approx. 4.87 Mohms

Scheme 28

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the KS connector. (See «KNOCK SENSOR (KS) REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S11236648192014101600000) .)
3. Disconnect the PCM connector.
4. Inspect the following wiring harnesses for open or short. (Continuity inspection)

CYLINDER HEAD TEMPERATURE (CHT) SENSOR INSPECTION [MZI-3.7]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS SERVICE INFORMATION .) Do not use the CHT sensor, install a new sensor.

Scheme 29

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the CHT sensor connector. (See «CYLINDER HEAD TEMPERATURE (CHT) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S14506382692014101600000) .)
3. Measure the resistance between the CHT sensor terminals A and B. If it is not within the specification, replace the CHT sensor.(See «CYLINDER HEAD TEMPERATURE (CHT) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S14506382692014101600000) .) If the monitor item status/specification (reference) is not within the specification, even though the resistance is within the specification, perform the "Circuit Open/Short Inspection". CHT sensor Resistance CHT SENSOR RESISTANCE CHART Cylinder head temperature (°C{°F}) Resistance (kilohm) 20 {68} 37.387 80 {176} 3.775

Cylinder head temperature sensor characteristics graph (reference)

Scheme 30

Scheme 31

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the CHT sensor connector. (See «CYLINDER HEAD TEMPERATURE (CHT) SENSOR REMOVAL/INSTALLATION [MZI-3.7]»(ref-663049-S14506382692014101600000) .)
3. Disconnect the PCM connector.
4. Inspect the following wiring harnesses for open or short. (Continuity inspection)

Voltage Inspection

1. Remove the evaporative hose component. (See «FUEL TANK REMOVAL/INSTALLATION [MZI-3.7]»(ref-663018-S09340888332014101600000) .)
2. Turn the ignition switch to the ON position.
3. Plug one end of the evaporative hose component and verify that the output voltage from the fuel tank pressure sensor changes when pressure is applied from the other hose end. If it cannot be verified even though the related harnesses have no malfunction, replace the evaporative hose component. (See «FUEL TANK REMOVAL/INSTALLATION [MZI-3.7]»(ref-663018-S09340888332014101600000) .) If the monitor item status/specification (reference) is not within the specification, even though the resistance is within the specification, perform the "Circuit Open/Short Inspection".

Scheme 32

1. Disconnect the negative battery cable. (See «BATTERY REMOVAL/INSTALLATION [MZI-3.7]»(ref-663012-S16021955892014101600000) .)
2. Disconnect the fuel tank pressure sensor connector.
3. Disconnect the PCM connector.
4. Inspect the following wiring harnesses for open or short. (Continuity inspection)