Mazda Protege 5. Manual - part 57

 

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Mazda Protege 5. Manual - part 57

 

 

ON-BOARD DIAGNOSTIC [ENGINE CONTROL SYSTEM (FS)]

01–02B–48

Diagnostic procedure

DTC P0123

TP circuit high input

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 REPAIR INFORMATION 
AVAILABILITY

Check for related Service Bulletins availability.

Is any related repair information available?

Yes Perform repair or diagnosis according to available repair 

information.

If vehicle is not repaired, go to next step.

No

Go to next step.

3

CHECK 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.

4

INSPECT TP SENSOR CONNECTOR FOR 
POOR CONNECTION

Disconnect TP sensor connector.

Check 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.

5

CHECK TP SENSOR RESISTANCE

Check resistance between following TP sensor 
terminals (part-side):
Terminals A and B: Within 3.2—4.8 kilohms
Terminals B and C: Within 0.2—1.2 kilohms

Are both resistances within specifications?

Yes Go to next step.

No

Replace TP sensor, then go to Step 9.

6

VERIFY TP SENSOR GROUND CIRCUIT FOR 
OPEN CIRCUIT AT TP SENSOR CONNECTOR

Check for continuity between TP sensor 
terminal B (harness-side) and body ground.

Is there continuity?

Yes Go to Step 8.

No

Go to next step.

1712-1U-01G(01-02B).fm  48 ページ  2001年6月29日 金曜日 午後3時24分

ON-BOARD DIAGNOSTIC [ENGINE CONTROL SYSTEM (FS)]

01–02B–49

01–02B

End Of Sie

DTC P0125 [FS]

A3U010201084W19

Diagnostic procedure

7

CHECK PCM CONNECTOR

Disconnect PCM connector.

Check for poor connection at terminals 89, 90 
and 91 (damaged/pulled-out terminals, 
corrosion, etc.).

Is there any malfunction?

Yes Repair terminal, then go to Step 9.

No

Repair or replace open circuit in wiring harness between 
TP sensor terminal B and PCM connector terminal 91 
(harness-side). Then, go to Step 9.

8

VERIFY TP SIGNAL CIRCUIT FOR SHORT TO 
CONSTANT VOLTAGE CIRCUIT

Check for continuity between TP sensor 
terminals A 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.

Start engine.

Clear DTC from PCM memory using WDS or 
equipment.

Depress and release accelerator pedal several 
times.

Does the same DTC appear?

Yes Replace PCM, then go to next step.

No

Go to next step.

10

VERIFY AFTER REPAIR PROCEDURE

Perform “After Repair Procedure”.
(See 01–02B–9 AFTER REPAIR 
PROCEDURE [FS].)

Is there any DTC present?

Yes Go to applicable DTC inspection.

(See 01–02B–15 DTC TABLE [FS].)

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 38 after engine is started engine is cold. If ECT voltage 
does not reach the expected temperature within 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.

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 REPAIR INFORMATION 
AVAILABILITY

Check for related Service Bulletins availability.

Is any related repair information available?

Yes Perform repair or diagnosis according to available repair 

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

Clear DTC using WDS or equivalent.

Start engine.

Warm up engine completely.

Access ECT PID using WDS or equivalent.

Is ECT PID above 35.6 

°°°°

C {96 

°°°°

F}?

Yes Intermittent concern exists. Go to INTERMITTENT 

CONCERN TROUBLESHOOTING procedure.
(See 01–03B–4 INTERMITTENT CONCERN 
TROUBLESHOOTING [FS].)

No

Go to next step.

1712-1U-01G(01-02B).fm  49 ページ  2001年6月29日 金曜日 午後3時24分

ON-BOARD DIAGNOSTIC [ENGINE CONTROL SYSTEM (FS)]

01–02B–50

End Of Sie

DTC P0126, P0128 [FS]

A3U010201084W20

4

INSPECT ECT SENSOR CONNECTOR FOR 
POOR CONNECTION

Turn ignition key to OFF.

Disconnect ECT sensor connector.

Check for poor connection (damaged/pulled-
out pins, corrosion, etc.).

Is there malfunction?

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

No

Go to next step.

5

INSPECT ECT SENSOR

Measure resistance between ECT sensor 
terminals A and B (part-side).

Is resistance approx. 2 kilohms?

Yes Go to next step.

No

Replace ECT sensor, then go to Step 7.

6

INSPECT PCM CONNECTOR FOR POOR 
CONNECTION

Disconnect PCM connector.

Check for poor connection at terminal 38 and 
91 (damaged/pulled-out pins, corrosion, etc.).

Is there malfunction?

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

No

Go to next step.

7

VERIFY TROUBLESHOOTING OF DTC P0125 
COMPLETED

Make sure to reconnect all disconnected 
connectors.

Turn ignition key to ON (Engine OFF).

Clear DTC from PCM memory using WDS or 
equivalent.

Access ECT PID using WDS or equivalent.

Wait until ECT PID is below 20 

°°°°

C {68 

°°°°

F}.

Start engine and warm it up completely.

Is PENDING CODE of same DTC present?

Yes Replace PCM, then go to next step.

No

Go to next step.

8

VERIFY AFTER REPAIR PROCEDURE

Perform “After Repair Procedure”.
(See 01–02B–9 AFTER REPAIR 
PROCEDURE [FS].)

Is there any DTC present?

Yes Go to applicable DTC inspection.

(See 01–02B–15 DTC TABLE [FS].)

No

Troubleshooting completed.

STEP

INSPECTION

ACTION

DTC P0126 
DTC P0128

Coolant thermostat stuck to open

DETECTION 

CONDITION

DTC P0126

 If 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}

— Difference between ECT at engine start and minimum IAT: Below 6

°°°°

C {43

°°°°

F}

— Vehicle speed over 9.5 km/h {5.9 mph}

DTC P0128

 PCM monitors MAF, IAT, VSS and ECT signals and calculate radiator's 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 35

°°°°

C {95

°°°°

F}

— IAT: Above -10

°°°°

C {14

°°°°

F}

— Difference between ECT at engine start and minimum IAT: Below 6

°°°°

C {43

°°°°

F}

— Vehicle speed above 25 km/h {15 mph} for ATX, 40 km/h {25 mph} for MTX

Diagnostic support note

This is a intermittent monitor (THERMOSTAT)

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

DIAGNOSTIC MONITORING TEST RESULTS is available.

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

Coolant thermostat malfunction

ECT sensor malfunction

PCM malfunction

1712-1U-01G(01-02B).fm  50 ページ  2001年6月29日 金曜日 午後3時24分

ON-BOARD DIAGNOSTIC [ENGINE CONTROL SYSTEM (FS)]

01–02B–51

01–02B

Diagnostic procedure

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 REPAIR INFORMATION 
AVAILABILITY

Check for related Service Bulletins availability.

Is any related repair information available?

Yes Perform repair or diagnosis according to available repair 

information.
If vehicle is not repaired, then go to next step.

No

Go to next step.

3

INSPECT FOR OTHER DTCs

Have other DTCs been stored?

Yes Repair circuit malfunction for applicable DTCs.

No

Go to next step.

4

VERIFY COOLANT THERMOSTAT OPERATION

Turn off E/L and A/C.

Remove cooling fan relay No.1 located next to 
main relay box.

Warm up engine until ECT PID reads 99

°°°°

{210

°°°°

F}.

Short cooling fan relay No.1 terminal A and B 
(harness–side) using a jumper wire.

Monitor ECT PID.

Has ECT PID decreased continuously and stop 
at 80—84

°°°°

C {176—183

°°°°

F} (thermostat 

closed)?

Yes Go to step 6.

No

Go to next step.

5

INSPECT COOLANT THERMOSTAT FOR 
WHETHER STUCK OPEN

Remove coolant thermostat and inspect for 
stuck open.
(See 01–12–7 THERMOSTAT INSPECTION.)

Is thermostat okay?

Yes Inspect ECT sensor.

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

No

Replace coolant thermostat, then go to next step.

6

VERIFY MONITORING CONDITION FOR 
REPAIR VERIFICATION

Make sure to reconnect all disconnected 
connectors.

Cool down engine.

Note

If workshop inside and outside temperature 
difference is significant, PCM might not 
operate thermostat monitor. Therefore, it is 
recommended to cool down engine out of 
workshop.

Turn ignition key to ON (Engine OFF).

Clear DTC from PCM memory using WDS or 
equivalent.

Access ECT, IAT PIDs and make sure that 
each value is within following conditions.
— ECT: below 31

°°°°

C {88

°°°°

F} (for P0128 only)

— IAT: above –10

°°°°

C {14

°°°°

F}

— Difference between ECT and IAT: below 

6

°°°°

C {43

°°°°

F}

Is there any PID that is out of specification?

Yes Take corrective action (e.g. cool down engine), then repeat 

this step.

No

Go to next step for DTC P0126 or go to step 8 for DTC 
P0128.

1712-1U-01G(01-02B).fm  51 ページ  2001年6月29日 金曜日 午後3時24分

 

 

 

 

 

 

 

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