Mazda Protege 5. Manual - part 19

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

01–02A–42

End Of Sie

DTC P0122 [ZM]

A3U010201084W43

4

CLASSIFY ECT SENSOR OR HARNESS 
MALFUNCTION

•

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

•

Is resistance within 0.111—25.403 kilohms? 

Yes Go to next step.

No

Replace ECT sensor, then go to Step 10.

5

INSPECT ECT SENSOR SIGNAL CIRCUIT FOR 
SHORT TO POWER

•

Turn ignition key to ON (Engine OFF).

•

Measure voltage between ECT sensor terminal 
A (harness-side) and body ground.

•

Is there voltage B+?

Yes Repair or replace harness for short to power, then go to 

Step 10.

No

Go to next step.

6

INSPECT PCM CONNECTOR FOR POOR 
CONNECTION

•

Disconnect PCM connector.

•

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

•

Is there malfunction?

Yes Repair or replace terminal, then go to Step 10.

No

Go to next step.

7

INSPECT ECT SENSOR SIGNAL CIRCUIT FOR 
OPEN CIRCUIT

•

Connect breakout box with PCM disconnected.

•

Check for continuity between ECT sensor 
terminal A (harness-side) and breakout box 
terminal 38.

•

Is there continuity?

Yes Go to next step.

No

Repair or replace harness for open, then go to Step 10.

8

INSPECT ECT SENSOR GROUND CIRCUIT 
FOR OPEN CIRCUIT

•

Check for continuity between ECT sensor 
terminal B (harness-side) and breakout box 
terminal 91.

•

Is there continuity?

Yes Go to next step.

No

Repair or replace harness for open, then go to next step.

9

VERIFY TROUBLESHOOTING OF DTC P0118 
COMPLETED

•

Make sure to reconnect all disconnected 
connectors.

•

Clear DTC from PCM memory using WDS or 
equivalent.

•

Start engine.

•

Is same DTC present?

Yes Replace PCM, then go to next step.

No

No concern is detected. Go to next step.

10

VERIFY AFTER REPAIR PROCEDURE

•

Perform “After Repair Procedure”.
(See 01–02A–10 AFTER REPAIR 
PROCEDURE [ZM].)

•

Is there any DTC present?

Yes Go to applicable DTC inspection.

(See 01–02A–15 DTC TABLE [ZM].)

No

Troubleshooting completed.

STEP

INSPECTION

ACTION

DTC P0122

TP circuit low input

DETECTION 

CONDITION

•

If PCM detects TP sensor voltage at PCM terminal 89 below 0.10 V after engine start, PCM determines 
that TP circuit has a malfunction.

Diagnostic support note

•

This is a continuous monitor (CCM).

•

MIL illuminates if PCM detects the above malfunction conditions during first drive cycle. Therefore, 
PENDING CODE is not available.

•

FREEZE FRAME DATA is available.

•

DTC is stored in PCM memory.

POSSIBLE 

CAUSE

•

TP sensor malfunction

•

Connector or terminal malfunction

•

Open circuit between TP sensor terminal C and PCM terminal 89

•

Short to ground circuit between TP sensor terminal C and PCM terminal 89

•

Open circuit between TP sensor terminal A and PCM terminal 90

•

Short to ground circuit between TP sensor terminal A and PCM terminal 90

•

PCM malfunction

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

01–02A–43

01–02A

Diagnostic procedure

DTC P0122

TP circuit low 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 CIRCUIT FOR OPEN 
CIRCUIT

•

Turn ignition key to OFF.

•

Check for continuity between TP sensor 
terminals A and C (part-side).

•

Is there continuity?

Yes Check TP sensor connector terminal A for poor connection. 

Repair or replace as necessary, then go to Step 8.

No

Go to Step 8.

4

CHECK POWER SUPPLY CIRCUIT VOLTAGE 
AT TP SENSOR CONNECTOR

Note

•

If DTC P0107 and P0452 are also retrieved 
with P0122, go to REFERENCE VOLTAGE 
troubleshooting procedure.
(See 01–03A–50 NO.30 CONSTANT 
VOLTAGE [ZM].)

•

Turn ignition key to ON (Engine OFF).

•

Check voltage at TP sensor terminal A 
(harness-side).

•

Is voltage within 4.5—5.5 V?

Yes Go to next step.

No

Repair or replace open circuit in wiring harness between 
TP sensor terminal A (harness-side) and PCM terminal 90 
(harness-side), then go to Step 8.

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

01–02A–44

End Of Sie

5

VERIFY TP SIGNAL CIRCUIT FOR OPEN 
CIRCUIT

•

Turn ignition key to OFF.

•

Disconnect PCM connector.

•

Connect breakout box with PCM disconnected.

•

Disconnect TP sensor connector.

•

Check for continuity between TP sensor 
terminal C (harness-side) and breakout box 
terminal 89.

•

Is there continuity?

Yes Go to next step.

No

Repair or replace suspected harness, then go to Step 8.

6

VERIFY TP SIGNAL CIRCUIT FOR SHORT TO 
GROUND

•

Check for continuity between TP sensor 
connector terminal C and body ground.

•

Is there continuity?

Yes Repair or replace suspected harness, then go to Step 8.

No

Go to next step.

7

INSPECT TP SENSOR

•

Perform TP sensor inspection.
(See 01–40A–28 THROTTLE POSITION (TP) 
SENSOR INSPECTION [ZM].)

•

Is TP sensor Okay?

Yes Go to next step.

No

Replace TP sensor.

8

VERIFY TROUBLESHOOTING OF DTC P0122 
COMPLETED

•

Make sure to reconnect all disconnected 
connectors.

•

Start engine.

•

Clear DTC from PCM memory using WDS or 
equivalent.

•

Depress and release accelerator pedal several 
times.

•

Is same DTC present?

Yes Replace PCM, then go to next step.

No

Go to next step.

9

VERIFY AFTER REPAIR PROCEDURE

•

Perform “After Repair Procedure”.
(See 01–02A–10 AFTER REPAIR 
PROCEDURE [ZM].)

•

Is there any DTC present?

Yes Go to applicable DTC inspection.

(See 01–02A–15 DTC TABLE [ZM].)

No

Troubleshooting completed.

STEP

INSPECTION

ACTION

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

01–02A–45

01–02A

DTC P0123 [ZM]

A3U010201084W44

Diagnostic procedure

DTC P0123

TP circuit high input

DETECTION 

CONDITION

•

If PCM detects TP sensor voltage at PCM terminal 89 is above 4.77 V after engine start, PCM determines 
that TP circuit has a malfunction.

Diagnostic support note

•

This is a continuous monitor (CCM).

•

MIL illuminates if PCM detects the above malfunction conditions during first drive cycle. Therefore, 
PENDING CODE is not available.

•

FREEZE FRAME DATA is available.

•

DTC is stored in PCM memory.

POSSIBLE 

CAUSE

•

TP sensor malfunction

•

Connector or terminal malfunction

•

Open circuit between TP sensor terminal B and PCM terminal 91

•

Short to reference voltage (Vref) supply circuit between TP sensor terminal C and PCM terminal 89

•

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

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.

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