Mazda CX 7. Manual — part 150

CONTROL SYSTEM [L3 WITH TC]

01-40–41

01-40

Open circuit

• If there is no continuity, there is an open circuit. Repair or replace the wiring harness.

— Rear HO2S terminal A and PCM terminal 2Q

— Rear HO2S terminal B and PCM terminal 1BC

Short circuit

• If there is continuity, there is a short circuit. Repair or replace the wiring harness.

— Rear HO2S terminal A and body ground

— Rear HO2S terminal A and power supply

— Rear HO2S terminal B and power supply

Rear HO2S Heater Resistance Inspection

1. Disconnect the rear HO2S connector.
2. Measure the rear HO2S resistance between

terminals C and D.

• If not within the specification, replace the

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 check)

Open circuit

• If there is no continuity, there is an open circuit. Repair or replace the wiring harness.

— Rear HO2S terminal C and ignition switch

— Rear HO2S terminal D and PCM terminal 2D

Short circuit

• If there is no continuity, there is a short circuit. Repair or replace the wiring harness.

Rear

— Rear HO2S terminal A and body ground

— Rear HO2S terminal B and power supply

— Rear HO2S terminal B and body ground

REAR HO2S

A

B

C

D

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REAR HO2S

WIRING HARNESS SIDE CONNECTOR

A

B

C

D

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2BE 2BA 2AW 2AS 2AO 2AK 2AG 2AC 2Y 2U 2Q 2M

2E

2A

2I

2BH 2BD 2AZ 2AV 2AR 2AN 2AJ 2AF 2AB 2X 2T 2P

2H

2D

2L

2BG 2BC 2AY 2AU 2AQ 2AM 2AI 2AE 2AA 2W 2S 2O

2G

2C

2K

2BF 2BB 2AX 2AT 2AP 2AL 2AH 2AD 2Z

2V 2R 2N

2F

2B

2J

1BE 1BA 1AW 1AS 1AO 1AK 1AG 1AC 1Y 1U 1Q 1M

1E

1A

1I

1BH 1BD 1AZ 1AV 1AR 1AN 1AJ 1AF 1AB 1X

1T

1P

1H

1D

1L

1BG 1BC 1AY 1AU 1AQ 1AM 1AI 1AE 1AA 1W 1S 1O

1G

1C

1K

1BF 1BB 1AX 1AT 1AP 1AL 1AH 1AD 1Z

1V

1R 1N

1F

1B

1J

PCM

WIRING HARNESS-SIDE CONNECTOR

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CONTROL SYSTEM [L3 WITH TC]

01-40–42

End Of Sie
WM: CRANKSHAFT POSITION PLATE

CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION[L3 WITH TC]

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Removal

1. Disconnect the negative battery cable.
2. Remove the charge air cooler duct. (See01-13-5 INTAKE AIR SYSTEM REMOVAL/INSTALLATION[L3 WITH

TC].)

3. Remove the under cover.
4. Remove the splash shield (RH).
5. Disconnect the CKP sensor connector.
6. Remove the installation bolts to remove the CKP sensor.

Installation

Caution

• When foreign material, such as an iron chips, gets on the CKP sensor, it can cause abnormal

output from the sensor because of flux turbulence and adversely affect engine control. Be sure
there is no foreign material on the CKP sensor when replacing.

1. Perform the following procedure so that piston No.1 is at the top dead center.

(1) Rotate the crankshaft in the direction of the

engine rotation and remove the cylinder block
lower blind plug when the No. 1 cylinder is at
the point prior to top dead center (TDC) of
compression, then install the SST.

(2) Rotate the crankshaft in the direction of the

engine rotation so that the No.1 piston is at
TDC of the compression stroke. (Until the
crank weight contacts SST and stops.)

2. Using a straight edge, draw a straight line directly

in the center of the twentieth tooth of the
crankshaft pulley pulse wheel (counting
counterclockwise from the empty space).

Caution

• If the line is not accurately drawn,

ignition timing, fuel injection and other
engine control systems will be adversely
effected. Draw the straight line carefully
using a straight edge.

3. Align the center line of the crankshaft position

sensor and the line drawn in Step 2, then install
the sensor.

4. Install the CKP sensor fitting bolts.

Tightening torque

5.5— 7.5 N·m {57— 76 kgf·cm, 49— 66 in·lbf}

5. Remove the SST then install the cylinder block lower blind plug.

Tightening torque

18— 22 N·m {1.9— 2.2 kgf·m, 14— 16 ft·lbf}

End Of Sie

303-507

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EMPTY SPACE

MARK LINE AT CENTER
OF 20TH TOOTH

CENTER LINE
OF SENSOR

CKP SENSOR

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CONTROL SYSTEM [L3 WITH TC]

01-40–43

01-40

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

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Note

• Before performing the following inspection, make sure to follow the procedure as indicated in the

troubleshooting flowchart. (See 00-00-3 HOW TO USE THIS MANUAL.)

Air Gap Inspection

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}

Visual Inspection

1. Disconnect the negative battery cable.
2. Remove the CKP sensor. (See01-40-42 CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/

INSTALLATION[L3 WITH TC].)

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”.

Voltage Inspection

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

*

: Output voltage varies with crankshaft rotation.

CKP SENSOR

AIR GAP

PROJECTION

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Terminal

Voltage (V)

Condition

A

Below 1.0

Under any condition

B

4.8 or more

High output

*

0.8 or less

Low output

*

C

B+

Under any condition

A

B

CKP SENSOR

WIRING HARNESS SIDE CONNECTOR

C

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CONTROL SYSTEM [L3 WITH TC]

01-40–44

Circuit Open/Short Inspection

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

Open circuit

• If there is no continuity, the circuit is open. Repair or replace the wiring harness.

— CKP sensor terminal A and PCM terminal 2P

— CKP sensor terminal B and PCM terminal 2W

— CKP sensor terminal C and main relay terminal E

Short circuit

• If there is continuity, the circuit is shorted. Repair or replace the wiring harness.

— CKP sensor terminal A and power supply

— CKP sensor terminal B and power supply

— CKP sensor terminal B and body ground

— CKP sensor terminal C and body ground

End Of Sie

WM: CAMSHAFT POSITION SENSOR

A

B

CKP SENSOR

WIRING HARNESS SIDE CONNECTOR

C

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FUSE BOX

(MAIN RELAY)

A

E

B

D

FRONT

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2BE 2BA 2AW 2AS 2AO 2AK 2AG 2AC 2Y 2U 2Q 2M

2E

2A

2I

2BH 2BD 2AZ 2AV 2AR 2AN 2AJ 2AF 2AB 2X 2T 2P

2H

2D

2L

2BG 2BC 2AY 2AU 2AQ 2AM 2AI 2AE 2AA 2W 2S 2O

2G

2C

2K

2BF 2BB 2AX 2AT 2AP 2AL 2AH 2AD 2Z

2V 2R 2N

2F

2B

2J

1BE 1BA 1AW 1AS 1AO 1AK 1AG 1AC 1Y 1U 1Q 1M

1E

1A

1I

1BH 1BD 1AZ 1AV 1AR 1AN 1AJ 1AF 1AB 1X

1T

1P

1H

1D

1L

1BG 1BC 1AY 1AU 1AQ 1AM 1AI 1AE 1AA 1W 1S 1O

1G

1C

1K

1BF 1BB 1AX 1AT 1AP 1AL 1AH 1AD 1Z

1V

1R 1N

1F

1B

1J

PCM

WIRING HARNESS-SIDE CONNECTOR

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