Mazda 6. Manual - part 145

F–102

ON-BOARD DIAGNOSTIC 

End Of Sie

DTC P0123

A6E397001084W20

5

VERIFY TP SIGNAL CIRCUIT FOR OPEN 
CIRCUIT

• Turn ignition key to OFF.

• Inspect continuity between TP sensor terminal 

B (harness-side) and PCM terminal 2A.

• Is there continuity?

Yes Go to next step.

No

Repair or replace suspected harness, then go to Step 7.

6

VERIFY TP SIGNAL CIRCUIT FOR SHORT TO 
GROUND

• Inspect continuity between TP sensor terminal 

B (harness-side) and body ground.

• Is there continuity?

Yes Repair or replace suspected harness, then go to Step 7.

No

Go to next step.

7

VERIFY TROUBLESHOOTING OF DTC P0122 
COMPLETED

• Make sure to reconnect all disconnected 

connectors.

• Clear DTC from PCM memory using WDS or 

equivalent.

• Perform KOEO/KOER self-test.

(See 

F–66 KOEO/KOER SELF-TEST

.)

• Is same DTC present?

Yes Replace PCM, then go to next step.

(See 

F–43 PCM REMOVAL/INSTALLATION

.)

No

Go to next step.

8

VERIFY AFTER REPAIR PROCEDURE

• Perform “After Repair Procedure”.

(See 

F–66 AFTER REPAIR PROCEDURE

.)

• Is there any DTC present?

Yes Go to applicable DTC troubleshooting.

(See 

F–67 DTC TABLE

.)

No

Troubleshooting completed.

STEP

INSPECTION

ACTION

DTC P0123

TP circuit high input

DETECTION 

CONDITION

• If PCM detects TP sensor voltage at PCM terminal 2A is above 4.9 V after ignition key to on, the PCM 

determines that TP circuit has malfunction.

Diagnostic support note

• This is a continuous monitor (CCM).

• MIL illuminates if PCM detects the above malfunction condition in first drive cycles.

• PENDING CODE is available if PCM detects the above malfunction condition.

• FREEZE FRAME DATA is available.

• DTC is stored in the PCM memory.

POSSIBLE 

CAUSE

• TP sensor malfunction

• Connector or terminal malfunction

• Open circuit between TP sensor terminal A and PCM terminal 2H

• Short to constant voltage supply circuit between TP sensor terminal B and PCM terminal 2A 

ON-BOARD DIAGNOSTIC 

F–103

F

Diagnostic procedure

STEP

INSPECTION

ACTION

1

PERFORM DTC CONFIRMATION PROCEDURE

• Perform DTC CONFIRMATION PROCEDURE.

(See 

F–66 DTC CONFIRMATION 

PROCEDURE

.)

• Is same DTC present?

Yes Go to next step.

No

Intermittent concern exists. Go to INTERMITTENT 
CONCERN TROUBLESHOOTING procedure.
(See 

F–227 INTERMITTENT CONCERN 

TROUBLESHOOTING

.)

2

INSPECT TP SENSOR CONNECTOR

• Turn ignition key to OFF.

• Verify that the TP sensor connector is 

connected securely.

• Is connector okay?

Yes Go to next step.

No

Connect the connector securely, then go to Step 9.

3

INSPECT POOR CONNECTION OF TP SENSOR 
CONNECTOR

• Disconnect TP sensor connector.

• Inspect for poor connection (damaged, pulled-

out terminals, corrosion, etc.).

• Is there any malfunction?

Yes Repair or replace suspected terminal, then go to Step 9.

No

Go to next step.

4

INSPECT TP SENSOR

• Perform TP sensor inspection.

(See 

F–51 THROTTLE POSITION (TP) 

SENSOR INSPECTION

)

• Is TP sensor okay?

Yes Go to next step.

No

Replace TP sensor, then go to Step 9.

5

INSPECT TP SENSOR SIGNAL CIRCUIT FOR 
SHORT TO POWER

• Turn ignition key to ON (Engine OFF).

• Measure voltage between terminal B and body 

ground.

• Is voltage above 4.9?

Yes Repair or replace short to power circuit. Then, go to Step 9.

No

Go to next step.

6

VERIFY TP SENSOR GROUND CIRCUIT FOR 
OPEN CIRCUIT

• Inspect continuity between TP sensor 

connector terminal A and body ground.

• Is there continuity?

Yes Repair or replace open circuit between TP sensor 

connector terminal A (harness-side) and PCM connector 
terminal 2H (harness-side). Then, go to Step 9.

No

Go to next step.

DTC P0123

TP circuit high input

F–104

ON-BOARD DIAGNOSTIC 

End Of Sie

DTC P0125

A6E397001084W21

Diagnostic procedure

7

INSPECT PCM CONNECTOR

• Disconnect PCM connector.

• Inspect for poor connection (damaged, pulled-

out terminals, corrosion, etc.).

• Is there any malfunction?

Yes Repair terminal, then go to Step 9.

No

Go to Step 9.

8

VERIFY TP SIGNAL CIRCUIT FOR SHORT TO 
CONSTANT VOLTAGE CIRCUIT

• Inspect continuity between TP sensor 

connector terminals B and C.

• Is there continuity?

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

No

Go to next step.

9

VERIFY TROUBLESHOOTING OF DTC P0123 
COMPLETED

• Make sure to reconnect all disconnected 

connectors.

• Clear DTC from PCM memory using WDS or 

equivalent.

• Perform KOEO/KOER self-test.

(See 

F–66 KOEO/KOER SELF-TEST

.)

• Is same DTC present?

Yes Replace PCM, then go to next step.

(See 

F–43 PCM REMOVAL/INSTALLATION

.)

No

Go to next step.

10

VERIFY AFTER REPAIR PROCEDURE

• Perform “After Repair Procedure”.

(See 

F–66 AFTER REPAIR PROCEDURE

.)

• Is there any DTC present?

Yes Go to applicable DTC troubleshooting.

(See 

F–67 DTC TABLE

.)

No

Troubleshooting completed.

STEP

INSPECTION

ACTION

DTC P0125

Excessive time to enter closed loop fuel control

DETECTION 

CONDITION

• PCM monitors ECT sensor signal at PCM terminal 1M after engine is started while engine is cold. If engine 

coolant temperature does not reach the expected temperature for specified period, 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 (CCM).

• MIL illuminates if 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 drive cycle.

• FREEZE FRAME DATA is available.

• DTC is stored in PCM memory.

POSSIBLE 

CAUSE

• ECT sensor malfunction

• Poor connection of connectors

• PCM malfunction

STEP

INSPECTION

ACTION

1

VERIFY FREEZE FRAME DATA HAS BEEN 
RECORDED

• Has FREEZE FRAME DATA been recorded?

Yes Go to next step.

No

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

2

VERIFY RELATED SERVICE INFORMATION 
AVAILABILITY

• Check for related Service Information 

availability.

• Is any related Service Information available?

Yes Perform repair or diagnosis according to available Service 

Information.

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

No

Go to next step.

3

VERIFY CURRENT INPUT SIGNAL STATUS-IS 
CONCERN INTERMITTENT OR CONSTANT

• Start engine.

• Warm up engine completely.

• Access ECT PID using WDS or equivalent.

• Is ECT PID above 60 °C {140 °F}?

Yes Intermittent concern exists. Go to INTERMITTENT 

CONCERNS TROUBLESHOOTING procedure.
(See 

F–227 INTERMITTENT CONCERN 

TROUBLESHOOTING

.)

No

Go to next step.

4

INSPECT POOR CONNECTION OF ECT 
SENSOR CONNECTOR

• Turn ignition key to OFF.

• Disconnect ECT sensor connector.

• Inspect for poor connection (damaged, pulled-

out pins, corrosion, etc.).

• Are there any malfunctions?

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

No

Go to next step.

ON-BOARD DIAGNOSTIC 

F–105

F

End Of Sie

DTC P0131, P0132

A6E397001084W22

Diagnostic procedure

5

INSPECT ECT SENSOR

• Inspect ECT sensor.

(See 

F–53 ENGINE COOLANT 

TEMPERATURE (ECT) SENSOR 
INSPECTION

.)

• Is it okay?

Yes Go to next step.

No

Replace ECT sensor, then go to Step 7.

6

INSPECT POOR CONNECTION OF PCM 
CONNECTOR

• Disconnect PCM connector.

• Inspect for poor connection (damaged, pulled-

out pins, corrosion, etc.).

• Are there any malfunctions?

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

No

Go to next step.

7

VERIFY TROUBLESHOOTING OF DTC P0125 
COMPLETED

• Make sure to reconnect all disconnected 

connectors.

• Clear DTC from PCM memory using WDS or 

equivalent.

• Turn ignition key to ON (Engine OFF).

• Access ECT PID using WDS or equivalent.

• Wait until ECT PID below 20 °C {68 °F}.

• Start engine and warm it up completely.

• Is PENDING CODE the same as DTC stored?

Yes Replace PCM, then go to next step.

(See 

F–43 PCM REMOVAL/INSTALLATION

.)

No

Go to next step.

8

VERIFY AFTER REPAIR PROCEDURE

• Perform “After Repair Procedure”.

(See 

F–66 AFTER REPAIR PROCEDURE

.)

• Is there any DTC present?

Yes Go to applicable DTC troubleshooting.

(See 

F–67 DTC TABLE

.)

No

Troubleshooting completed.

STEP

INSPECTION

ACTION

DTC P0131
DTC P0132

Front HO2S stuck low
Front HO2S stuck high

DETECTION 

CONDITION

• PCM monitors input voltage from front HO2S when the following monitoring conditions are met. If input 

voltage from sensor remains below or above 0.45 V for 41.2 s, PCM determines that there is no front 
HO2S inversion.

MONITORING CONDITIONS

— Engine speed is above 1,500 rpm.
— Engine coolant temperature is above 80 

°C {176°F}.

Diagnostic support note

• This is a continuous monitor (CCM).

• MIL illuminates if 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 drive cycle.

• FREEZE FRAME DATA is available.

• DTC is stored in the PCM memory.

POSSIBLE 

CAUSE

• Front HO2S malfunction

• Front HO2S heater malfunction

• Fuel injector malfunction

• Pressure regulator malfunction

• Fuel pump malfunction

• Fuel delivery hose clogging or leakage

• Fuel filter clogging

• Fuel return hose clogging or leakage

• Air suction or leakage

• PCV valve malfunction

• Purge solenoid valve malfunction

• Purge solenoid hoses are hooked up incorrectly.

• Ignition coil malfunction

• Insufficient compression

• Engine malfunction

STEP

INSPECTION

ACTION

1

VERIFY FREEZE FRAME DATA HAS BEEN 
RECORDED

• Has FREEZE FRAME DATA been recorded?

Yes Go to next step.

No

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