Engine Control System (L3): Diagnosis Mazda 5 I

Inspection Using An Oscilloscope (Reference)

Shift solenoid A signal

NEUTRAL SWITCH INSPECTION [L3]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart.

Scheme 25

1. Remove the neutral switch. (See «NEUTRAL SWITCH REMOVAL/INSTALLATION [G35M-R]»(ref-244336-S15325510132006092100000) ).
2. Verify that the continuity between neutral switch terminals A and B is as indicated in the table. If it can be verified, perform the "Circuit Open/Short Inspection". If it cannot be verified, replace the neutral switch. TERMINALS CONTINUITY CHART Measured condition Continuity Rod pushed Continuity detected Except above No continuity

Circuit Open/Short Inspection

1. Disconnect the PCM connector.
2. Inspect the following wiring harness for an open or short circuit. (Continuity inspection)

Open circuit

1. If there is no continuity in the following wiring harnesses, there is an open circuit. Repair or replace the wiring harness. Neutral switch terminal A and PCM terminal 1S Neutral switch terminal B and body ground

Short circuit

Scheme 26

1. If there is continuity in the following wiring harnesses, there is a short circuit. Repair or replace the wiring harness. Neutral switch terminal A and power supply Neutral switch terminal A and body ground Neutral switch terminal B and power supply

CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [L3]

Note. Before performing the following inspection, make sure to follow the troubleshooting flowchart. (See FOREWORD [L3] ).

Scheme 27

1. Remove the CPP switch.
2. Verify that the continuity between CPP switch terminals A and B is as indicated in the table. If there is no malfunction, perform the "Circuit Open/Short Inspection". If there is any malfunction, replace the CPP switch. TERMINALS CONTINUITY CHART Measurement condition Continuity Push the rod. Continuity detected Except above No continuity

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

Open circuit

1. If there is no continuity in the following wiring harnesses, there is an open circuit. Repair or replace the wiring harness. CPP switch terminal B and PCM terminal 1O CPP switch terminal A and body ground

Short circuit

1. If there is continuity in the following wiring harnesses, there is a short circuit. Repair or replace the wiring harness. CPP switch terminal A and body ground CPP switch terminal A and body ground CPP switch terminal B and body ground

Scheme 28

1. Remove the battery cover. (See «BATTERY REMOVAL/INSTALLATION [L3]»(ref-244326-S41790335602006092100000) ).
2. Disconnect the negative battery cable.
3. Remove the plug hole cover.
4. Drain the engine coolant. (See «ENGINE COOLANT REPLACEMENT [L3]»(ref-244337-S29195014592006092100000) ).
5. Disconnect the ECT sensor connector.
6. Remove the ECT sensor using the SST .
7. Install in the reverse order of removal. Tightening torque 10-14 N.m {102-142 kgf.cm, 89-123 in.lbf}

Resistance Inspection

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart.

1. Disconnect the ECT sensor connector.
2. Remove the ECT sensor. (See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [L3]»(ref-244330-S17883351852006092100000) ).
3. Place the ECT sensor in the water and while increasing the water temperature, measure the resistance between ECT sensor terminals A and B. If the monitor item status/specification (reference) is not within the specification, even though the ECT sensor resistance is within the specification, perform the "Circuit Open/Short Inspection". If not within the specification, replace the ECT sensor.

Standard

TEMPERATURE AND RESISTANCE CHART

Scheme 29

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

Open circuit

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness.
2. ECT sensor terminal A and PCM terminal 2AK
3. ECT sensor terminal B and PCM terminal 2AA

Short circuit

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. ECT sensor terminal A and power supply ECT sensor terminal A and body ground ECT sensor terminal B and power supply

INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTION [L3]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart.

Scheme 30

1. Disconnect the mass air flow sensor connector.
2. Verify that the resistance between MAF sensor terminals D and E is within the specification. If the monitor item status/specification (reference) is not within the specification, even though the IAT sensor resistance is within the specification, perform the "Circuit Open/Short Inspection". If not within the specification, replace the MAF sensor.

Standard

TEMPERATURE AND RESISTANCE CHART

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

Open circuit

Scheme 31

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. MAF/IAT sensor terminal D and PCM terminal 1AH MAF/IAT sensor terminal E and PCM terminal 1AA

Short circuit

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. MAF/IAT sensor terminal D and power supply MAF/IAT sensor terminal D and body ground MAF/IAT sensor terminal E and power supply

CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [L3]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart.

Scheme 32

1. Disconnect the CKP sensor connector.
2. Measure the resistance between CKP sensor connector terminals A and B. If not within the specification, replace the CKP sensor. 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", and repair or replace the malfunctioning part. Resistance 400-550 ohms

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

Open circuit

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. CKP sensor terminal A and PCM terminal 2Y CKP sensor terminal B and PCM terminal 2Z

Short circuit

Scheme 33

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. CKP sensor terminal A and power supply CKP sensor terminal A and body ground CKP sensor terminal B and power supply CKP sensor terminal B and body ground

CAMSHAFT POSITION (CMP) SENSOR INSPECTION [L3]

Note. Before performing the following inspection, make sure to follow the troubleshooting flowchart. (See FOREWORD [L3] ).

Scheme 34

1. Disconnect the CMP sensor connector.
2. Measure the resistance between CMP sensor connector terminals A and B . If not within the specification, replace the CMP sensor. 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", and repair or replace the malfunctioning part. Resistance 400-550 ohms

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

Open circuit

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. CMP sensor terminal A and PCM terminal 2V CMP sensor terminal B and PCM terminal 2U

Short circuit

Scheme 35

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. CMP sensor terminal A and power supply CMP sensor terminal A and body ground CMP sensor terminal B and power supply CMP sensor terminal B and body ground

Scheme 36

1. Remove the battery cover. (See «BATTERY REMOVAL/INSTALLATION [L3]»(ref-244326-S41790335602006092100000) ).
2. Disconnect the negative battery cable.
3. Remove the plug hole cover. CAUTION: When replacing the CMP sensor, make sure there is no foreign material on it such as metal shavings. If it is installed with foreign material, the sensor output signal will malfunction resulting from fluctuation in magnetic flux and cause a deterioration in engine control.
4. Disconnect the CMP sensor connector.
5. Remove the CMP sensor installation bolt.
6. Remove the CMP sensor from the cylinder head cover.
7. Install in the reverse order of removal. Tightening torque 5.5-7.5 N.m {57-76 kgf.cm, 49-66 in.lbf}

VARIABLE TUMBLE SHUTTER VALVE SWITCH INSPECTION [L3]

Note. Perform the following inspection only when directed.

Scheme 37

Scheme 38

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 tumble shutter valve actuator rod is depressed and released by hand. If not as specified, perform the "Circuit Open/Short Inspection". IF there is no open or short circuit, replace the intake manifold.

Variable tumble shutter valve switch output voltage

TERMINAL CONDITION CHART

1. Disconnect the PCM connector.
2. Inspect the following harness for an open or short wiring. (Continuity inspection)

Open circuit

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. Variable tumble shutter valve switch terminal A and PCM terminal 2W Variable tumble shutter valve switch terminal B and PCM terminal 2AA Variable tumble shutter valve switch terminal C and PCM terminal 2AE

Short circuit

Scheme 39

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. Variable tumble shutter valve switch terminal A and power supply Variable tumble shutter valve switch terminal A and body ground Variable tumble shutter valve switch terminal B and power supply Variable tumble shutter valve switch terminal C and power supply Variable tumble shutter valve switch terminal C and body ground

THROTTLE POSITION (TP) SENSOR INSPECTION [L3]

Note. Before performing the following inspection, make sure to follow the troubleshooting flowchart. (See FOREWORD [L3] ).

Scheme 40

1. Verify that no DTC related to APP sensor has been detected. If any DTCs related to APP sensor have been detected, perform the DTC inspection. (See «DTC TABLE [L3]»(ref-244323-S35277163902006092100000) ).
2. Connect the WDS or equivalent to the DLC-2.
3. Turn the ignition switch to ON position.
4. Select TP1 or TP2 PID (percentage) on the WDS or equivalent.
5. Verify that the TP1 or TP2 PID is within the specification when the accelerator pedal not depressed. (See «PCM INSPECTION [L3]»(ref-244330-S02642715442006092100000) ).
6. Operate the accelerator pedal and verify that the TP1 or TP2 PID (percentage) changes as shown in the following graph. 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 [L3]»(ref-244332-S08851886592006092100000) ).

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

Open circuit

Scheme 41

1. If there is no continuity in the following wiring harnesses, there is an open circuit. Repair or replace the wiring harness. Throttle body terminal A and PCM terminal 2M Throttle body terminal B and PCM terminal 2K Throttle body terminal C and PCM terminal 2I Throttle body terminal D and PCM terminal 2O

Short circuit

1. If there is continuity in the following wiring harnesses, there is a short circuit. Repair or replace the wiring harness. Throttle body terminal A and body ground Throttle body terminal A and power supply Throttle body terminal B and body ground Throttle body terminal B and power supply Throttle body terminal C and body ground Throttle body terminal C and power supply Throttle body terminal D and body ground Throttle body terminal D and power supply

ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [L3]

Note. Before performing the following inspection, make sure to follow the troubleshooting flowchart. (See FOREWORD [L3] ).

1. Connect the WDS or equivalent to the DLC-2.
2. Turn the ignition switch to ON position.
3. Select APP1 and APP2 PID on the WDS or equivalent.
4. Verify that the APP1 and APP2 PID is within the specification when the accelerator pedal not depressed. (See «PCM INSPECTION [L3]»(ref-244330-S02642715442006092100000) ).

Scheme 42

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

Open circuit

1. If there is no continuity in the following wiring harnesses, there is an open circuit. Repair or replace the wiring harness. APP sensor terminal A and PCM terminal 1AE APP sensor terminal B and PCM terminal 1Y APP sensor terminal C and PCM terminal 1AA APP sensor terminal D and PCM terminal body ground APP sensor terminal E and PCM terminal 1AL APP sensor terminal F and main relay terminal C

Short circuit

1. If there is continuity in the following wiring harnesses, there is a short circuit. Repair or replace the wiring harness. APP sensor terminal A and body ground APP sensor terminal A and power supply APP sensor terminal B and body ground APP sensor terminal B and power supply APP sensor terminal C and power supply APP sensor terminal D and power supply APP sensor terminal E and body ground APP sensor terminal E and power supply APP sensor terminal F and power supply APP sensor terminal F and body ground

MASS AIR FLOW (MAF) SENSOR INSPECTION [L3]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart.

Visual Inspection

1. Visually inspect the MAF sensor for the following: Damage, cracks Rusted sensor terminal Bent sensor terminal If there is any malfunction, replace the MAF 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 1AC (WDS PID: MAF) varies. If it cannot be verified even though the related harnesses have no malfunction, replace the MAF/IAT sensor. (See «INTAKE AIR SYSTEM REMOVAL/INSTALLATION [L3]»(ref-244332-S08851886592006092100000) ).

Scheme 43

1. Disconnect the PCM connector. (See «PCM REMOVAL/INSTALLATION [L3]»(ref-244330-S07461751642006092100000) ).
2. Disconnect the MAF sensor connector.
3. Inspect the following wiring harnesses for an open or short circuit. (Continuity inspection)

Open circuit

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. MAF sensor terminal A and main relay terminal C MAF sensor terminal B and PCM terminal 1 BD MAF sensor terminal C and PCM terminal 1 AC

Short circuit

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. MAF sensor terminal A and body ground MAF sensor terminal C and power supply MAF sensor terminal C and body ground MAF sensor terminal B and power supply

FRONT HEATED OXYGEN SENSOR (HO2S) INSPECTION [L3]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart.

Scheme 44

1. Warm up the engine to normal operating temperature.
2. Using the WDS or equivalent, monitor the following: Vehicle speed (PID: VSS) Engine speed (PID: RPM) Front HO2S voltage (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 front HO2S outputs a voltage of 0.6 V or more , one time or more, then verify that the front HO2S voltage (PID: O2S11) is 0.3 V or less while decelerating as shown in the figure. If not within the specification, inspect the HO2S for an open or short circuit. (See «FRONT HO2S CIRCUIT OPEN/SHORT INSPECTION (SENSOR)»(ref-244330-S37259266262006092100000) ). Then if there is no malfunction in the wiring harness, replace the front HO2S.

Front HO2S circuit open/short inspection (sensor)

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

Open circuit

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. HO2S terminal A and PCM terminal 2AG HO2S terminal B and PCM terminal 2AA

Short circuit

Scheme 45

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. HO2S terminal A and body ground HO2S terminal A and power supply HO2S terminal B and power supply

Scheme 46

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

Front HO2S heater circuit open/short inspection (heater)

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

Open circuit

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. HO2S terminal D and PCM terminal 2G

Short circuit

Scheme 47

1. If there is no continuity, there is a short circuit. Repair or replace the wiring harness. HO2S terminal C and body ground HO2S terminal D and power supply HO2S terminal D and body ground

REAR HEATED OXYGEN SENSOR (HO2S) INSPECTION [L3]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart.

Scheme 48

1. Warm up the engine to normal operating temperature.
2. Using the WDS or equivalent, monitor the following: Vehicle speed (PID: VSS) Engine speed (PID: RPM) Rear HO2S voltage (PID: O2S12)
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 rear HO2S outputs a voltage of 0.6 V or more , one time or more, then verify that the rear HO2S voltage (PID: O2S12) is 0.3 V or less while decelerating as shown in the figure. If not within the specification, inspect the HO2S for an open or short circuit. (See «REAR HO2S CIRCUIT OPEN/SHORT INSPECTION (SENSOR)»(ref-244330-S00102562022006092100000) ). Then if there is no malfunction in the wiring harness, replace the rear HO2S.

Rear HO2S circuit open/short inspection (sensor)

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

Open circuit

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. HO2S terminal A and PCM terminal 2AH HO2S terminal B and PCM terminal 2AA

Short circuit

Scheme 49

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. HO2S terminal A and body ground HO2S terminal A and power supply HO2S terminal B and power supply

Scheme 50

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

Rear HO2S circuit open/short inspection (heater)

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

Open circuit

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. HO2S terminal D and PCM terminal 2C

Short circuit

Scheme 51

1. If there is no continuity, there is a short circuit. Repair or replace the wiring harness. HO2S terminal C and body ground HO2S terminal D and power supply HO2S terminal D and body ground

MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR INSPECTION [L3]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart.

1. Remove the MAP sensor with the connector still connected. (See «MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR REMOVAL/INSTALLATION [L3]»(ref-244330-S08906892772006092100000) ).
2. Remove the vacuum hose of the MAP sensor.
3. Verify that the voltage at PCM terminal 2AL is within the specification when the ignition switch is turned to the ON position. If not within the specification, replace the MAP sensor. Voltage 2.69-4.37 V
4. Install the vacuum pump.
5. Turn the ignition switch to the ON position.
6. Verify that change in voltage is within the specification when a vacuum of 30 kPa {225 mm Hg, 8.86 in Hg} is applied using a vacuum pump. If not within the specification, replace the MAP sensor. Voltage variance 1.16-1.27 V

Scheme 52

1. Disconnect the PCM connector.
2. Inspect the following wiring harness for an open or short circuit. (Continuity inspection)

Open circuit

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. MAP sensor terminal A and PCM terminal 2AA MAP sensor terminal D and PCM terminal 2AL MAP sensor terminal C and PCM terminal 2W

Short circuit

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. MAP sensor terminal A and power supply. MAP sensor terminal C and body ground. MAP sensor terminal D and power supply. MAP sensor terminal D and body ground

Scheme 53

1. Remove the battery cover. (See «BATTERY REMOVAL/INSTALLATION [L3]»(ref-244326-S41790335602006092100000) ).
2. Disconnect the negative battery cable.
3. Remove the plug hole cover.
4. Remove the vacuum hose.
5. Disconnect the MAP sensor connector.
6. Remove the MAP sensor installation screw.
7. Remove MAP sensor from the intake manifold.
8. Install in the reverse order of removal. Tightening torque 2.7-3.7 N.m {28-37 kgf.cm, 24-32 in.lbf}

KNOCK SENSOR (KS) INSPECTION [L3]

Note. Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart.

1. Disconnect the knock sensor connector.
2. Measure resistance between KS terminals A and B. If not within the specification, replace the KS. If the monitor item status/specification (reference) is not within the specification, even though the KS resistance is within the specification, perform the "Circuit Open/Short Inspection". Resistance Approx. 4.87 megohms

Scheme 54

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

Open circuit

1. If there is no continuity, there is an open circuit. Repair or replace the wiring harness. Knock sensor terminal A and PCM terminal 2Q Knock sensor terminal B and PCM terminal 2R

Short circuit

1. If there is continuity, there is a short circuit. Repair or replace the wiring harness. Knock sensor terminal A and power supply Knock sensor terminal A and body ground Knock sensor terminal B and power supply Knock sensor terminal B and body ground

Scheme 55

1. Remove the following part for easier access. Intake manifold (See «INTAKE AIR SYSTEM REMOVAL/INSTALLATION [L3]»(ref-244332-S08851886592006092100000) ).
2. Disconnect the KS connector.
3. Remove the KS installation bolt, then remove the KS.
4. Install in the reverse order of removal. Tightening torque 16-24 N.m {1.7-2.4 kgf.m, 12-17 ft.lbf}

BAROMETRIC PRESSURE (BARO) SENSOR INSPECTION [L3]

Note. Perform the following inspection only when directed. The following vacuum values are indicated by relative pressure from the PCM. (See PCM REMOVAL/INSTALLATION [L3] ).

1. Connect the WDS or equivalent to the DLC-2.
2. Turn the ignition switch to the ON position.
3. Select BARO on the WDS or equivalent.
4. Verify that the BARO 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 PCM.