Mazda CX 7. Manual — part 29

ON-BOARD DIAGNOSTIC [L3 WITH TC]

01-02–71

01-02

Diagnostic procedure

STEP

INSPECTION

ACTION

1

VERIFY FREEZE FRAME DATA HAS BEEN
RECORDED

• Has the FREEZE FRAME DATA been

recorded?

Yes

Go to the next step.

No

Record FREEZE FRAME DATA on the repair order, then go
to the next step.

2

VERIFY RELATED REPAIR INFORMATION
AVAILABILITY

• Check for related Service Bulletins and/or on-

line repair information availability.

• Is any related repair information available?

Yes

Perform the repair or diagnosis according to the available
repair information.

• If the vehicle is not repaired, go to the next step.

No

Go to the next step.

3

INSPECT THROTTLE BODY CONNECTOR

• Turn the ignition switch off.

• Verify that the throttle body connector is

connected securely.

• Is connector normal?

Yes

Go to the next step.

No

Connect the connector securely, then go to Step 10.

4

INSPECT THROTTLE BODY CONNECTION FOR
POOR CONNECTION

• Disconnect throttle body connector.

• Inspect for poor connection (such as damaged/

pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the suspected wiring terminal, then go to
Step 10.

No

Go to the next step.

5

INSPECT TP SENSOR

• Perform the TP sensor inspection.

(See01-40-32 THROTTLE POSITION (TP)
SENSOR INSPECTION[L3 WITH TC])

• Is the TP sensor normal?

Yes

Go to the next step.

No

Replace the throttle body, then go to Step 10.

DTC P0123

TP sensor No.1 circuit high input

B

A

D

PCM

(THROTTLE BODY)

3

5

8

6

3

2AO

2AK

2AP

9

7

4

4

4

3

8

8

PCM

HARNESS SIDE CONNECTOR

THROTTLE BODY

HARNESS SIDE CONNECTOR

B

A

D

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

TP SENSOR NO.1

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ON-BOARD DIAGNOSTIC [L3 WITH TC]

01-02–72

End Of Sie

DTC P0125[L3 WITH TC]

id010239804400

6

INSPECT TP1 SIGNAL CIRCUIT FOR OPEN
CIRCUIT

• Turn ignition switch to the ON position (Engine

off).

• Measure the voltage between throttle body

terminal B (harness-side) and body ground.

• Is the voltage above 4.9 V?

Yes

Go to the next step.

No

Repair or replace for short to a power supply. Then, go to
Step 10.

7

VERIFY TP SENSOR GROUND CIRCUIT FOR
OPEN CIRCUIT

• Inspect for continuity between throttle body

connector terminal D (harness-side) and PCM
connector terminal 2AP.

• Is there continuity?

Yes

Go to the next step.

No

Repair or replace for an open circuit between TP sensor
connector terminal B (harness-side) and PCM connector
terminal 3P (harness-side). Then, go to Step 10.

8

INSPECT PCM CONNECTOR FOR POOR
CONNECTION

• Disconnect the PCM connector.

• Inspect for poor connection (such as damaged/

pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair terminal, then go to Step 10.

No

Go to Step 10.

9

VERIFY TP SIGNAL CIRCUIT FOR SHORT TO
CONSTANT VOLTAGE CIRCUIT

• Inspect for continuity between throttle body

terminals A and B (harness-side).

• Is there continuity?

Yes

Repair or replace the suspected wiring harness, then go to
the next step.

No

Go to the next step.

10

VERIFY TROUBLESHOOTING OF DTC P0123
COMPLETED

• Make sure to reconnect all disconnected

connectors.

• Turn ignition switch to the ON position (Engine

off).

• Clear the DTC from the PCM memory using

the M-MDS.

• Start the engine and warm it up completely.

• Is same DTC present?

Yes

Replace PCM, then go to the next step.
(See01-40-6 PCM REMOVAL/INSTALLATION[L3 WITH
TC].)

No

Go to the next step.

11

VERIFY AFTER REPAIR PROCEDURE

• Perform the “After Repair Procedure”.

(See01-02-10 AFTER REPAIR
PROCEDURE[L3 WITH TC].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.
(See01-02-13 DTC TABLE[L3 WITH TC].)

No

Troubleshooting completed.

STEP

INSPECTION

ACTION

DTC P0125

Excessive time to enter closed loop fuel control

DETECTION

CONDITION

• The PCM monitors the ECT sensor signal after the engine is started while the engine is cold. If the engine

coolant temperature does not reach the expected temperature for a specified period, the PCM determines
that it has taken an excessive amount of time for the engine coolant temperature to reach the temperature
necessary to start closed-loop fuel control.

Diagnostic support note

• This is a continuous monitor (Engine cooling system).

• MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in

one drive cycle while the DTC for the same malfunction has been stored in the PCM.

• PENDING CODE is available if the PCM detects the above malfunction condition during the first drive

cycle.

• FREEZE FRAME DATA is available.

• DTCs are stored in the PCM memory.

POSSIBLE

CAUSE

• ECT sensor malfunction

• Cooling system malfunction

• Poor connection of connectors

• PCM malfunction

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ON-BOARD DIAGNOSTIC [L3 WITH TC]

01-02–73

01-02

Diagnostic procedure

End Of Sie

STEP

INSPECTION

ACTION

1

VERIFY FREEZE FRAME DATA AND
DIAGNOSTIC MONITORING TEST RESULTS
HAVE BEEN RECORDED

• Have the FREEZE FRAME DATA and

DIAGNOSTIC MONITORING TEST RESULTS
(Engine cooling system related) been
recorded?

Yes

Go to the next step.

No

Record FREEZE FRAME DATA and DIAGNOSTIC
MONITORING TEST RESULTS on the repair order, then
go to the next step.

2

VERIFY RELATED SERVICE INFORMATION
AVAILABILITY

• Verify related Service Information availability.

• Is any related Service Information available?

Yes

Perform the repair or diagnosis according to available
Service Information.

• If the vehicle is not repaired, go to the next step.

No

Go to the next step.

3

VERIFY CURRENT INPUT SIGNAL STATUS: IS
CONCERN INTERMITTENT OR CONSTANT

• Start the engine.

• Warm up the engine completely.

• Access the ECT PID using the M-MDS.

• Is the ECT PID above 60 °C {140 °F}?

Yes

Intermittent concern exists. Go to the INTERMITTENT
CONCERNS TROUBLESHOOTING procedure.
(See01-03-76 INTERMITTENT CONCERN
TROUBLESHOOTING[L3 WITH TC].)

No

Go to the next step.

4

INSPECT ECT SENSOR CONNECTOR FOR
POOR CONNECTION

• Turn the ignition switch off.

• Disconnect the ECT sensor connector.

• Inspect for poor connection (such as damaged/

pulled-out pins, corrosion.)

• Is there any malfunction?

Yes

Repair or replace the terminal, then go to Step 7.

No

Go to the next step.

5

INSPECT ECT SENSOR

• Inspect the ECT sensor.

(See01-40-25 ENGINE COOLANT
TEMPERATURE (ECT) SENSOR
INSPECTION[L3 WITH TC].)

• Is it normal?

Yes

Go to the next step.

No

Replace the ECT sensor, then go to Step 7.

6

INSPECT PCM CONNECTOR FOR POOR
CONNECTION

• Disconnect the PCM connector.

• Inspect for poor connection (such as damaged/

pulled-out pins, corrosion.)

• Is there any malfunction?

Yes

Repair or replace the terminal, then go to the next step.

No

Go to the next step.

7

VERIFY TROUBLESHOOTING OF DTC P0125
COMPLETED

• Make sure to reconnect all disconnected

connectors.

• Clear the DTC from the PCM memory using

the M-MDS.

• Turn the ignition switch to the ON position

(Engine off).

• Access the ECT PID using the M-MDS.

• Wait until ECT PID below 8 °C {46 °F}.

• Start the engine and warm it up completely.

• Is the PENDING CODE for this DTC present?

Yes

Replace the PCM, then go to the next step.
(See01-40-6 PCM REMOVAL/INSTALLATION[L3 WITH
TC].)

No

Go to the next step.

8

VERIFY AFTER REPAIR PROCEDURE

• Perform the “AFTER REPAIR PROCEDURE”.

(See01-02-10 AFTER REPAIR
PROCEDURE[L3 WITH TC].)

• Are any DTCs present?

Yes

Go to the applicable DTC troubleshooting.
(See01-02-13 DTC TABLE[L3 WITH TC].)

No

Troubleshooting completed.

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ON-BOARD DIAGNOSTIC [L3 WITH TC]

01-02–74

DTC P0126, P0128[L3 WITH TC]

id010239815400

Diagnostic procedure

DTC P0126
DTC P0128

Coolant thermostat stuck open

DETECTION

CONDITION

DTC P0126

• If the ECT signal never exceeds 71 °C {160 °F} after engine start for specified period, PCM determines that

the coolant thermostat is stuck open.

MONITORING CONDITIONS

— IAT: above –10 °C {14 °F}

— Vehicle speed: over 9.4 km/h {5.8 mph}

DTC P0128

• PCM monitors MAF, IAT, VSS and EAT signals and calculate radiator heat radiation ratio while following

monitoring conditions are met. If calculated value exceeds threshold, PCM determines that the coolant
thermostat is stuck open.

MONITORING CONDITIONS

— ECT at engine start: below 36 °C {97 °F}

— IAT: above –10 °C {14 °F}

— Difference between ECT at engine start and minimum IAT: below 6 °C {10.8 °F}

— Vehicle speed: over 32 km/h {20 mph}

Diagnostic support note

• This is an intermittent monitor (Engine cooling system).

• MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in

one drive cycle while the DTC for the same malfunction has been stored in the PCM.

• PENDING CODE is available if PCM detects the above malfunction condition during first the drive cycle.

• FREEZE FRAME DATA is available.

• DTC is stored in PCM memory.

• DIAGNOSTIC MONITORING TEST RESULTS is available.

POSSIBLE
CAUSE

• ECT sensor malfunction

• Coolant thermostat malfunction

• PCM malfunction

STEP

INSPECTION

ACTION

1

VERIFY FREEZE FRAME DATA AND
DIAGNOSTIC MONITORING TEST RESULTS
HAVE BEEN RECORDED

• Have FREEZE FRAME DATA and

DIAGNOSTIC MONITORING TEST RESULTS
(Engine cooling system related) been
recorded?

Yes

Go to the next step.

No

Record FREEZE FRAME DATA and DIAGNOSTIC
MONITORING TEST RESULTS on repair order, then go to
the next step.

2

VERIFY RELATED REPAIR INFORMATION
AVAILABILITY

• Check for related Service Bulletins and/or on-

line repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to the available
repair information.

• If the vehicle is not repaired, go to the next step.

No

Go to the next step.

3

INSPECT FOR OTHER DTCS

• Have other DTCs been stored?

Yes

Repair circuit malfunction for applicable DTCs.

No

Go to the next step.

4

INSPECT COOLANT THERMOSTAT FOR
WHETHER STUCK OPEN

• Perform coolant thermostat inspection.

• Is coolant thermostat normal?

Yes

Inspect ECT sensor.
Replace ECT sensor if necessary, then go to the next step.

No

Replace coolant thermostat, then go to the next step.

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