Mazda Protege 5. Manual - part 79

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

01–02B–136

End Of Sie

4

INSPECT EGR VALVE FOR POOR 
CONNECTION

•

Turn ignition key to OFF.

•

Disconnect EGR valve connector.

•

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

•

Is there malfunction?

Yes Repair or replace terminals, then go to Step 11.

No

Go to next step.

5

INSPECT POWER CIRCUIT FOR OPEN 
CIRCUIT

•

Turn ignition key to ON (Engine OFF).

•

Measure voltage between EGR valve terminal 
C (harness-side) and body ground.

•

Is voltage B+?

Yes Inspect EGR valve coils 1 and 2.

(See 01–16–15 EGR VALVE INSPECTION.)

•

If there is a malfunction, replace EGR valve, and then 
go to Step 11.

•

If there is no malfunction, go to Step 11.

No

Repair or replace harness, then go to Step 11.

6

INSPECT EGR VALVE FOR POOR 
CONNECTION

•

Turn ignition key to OFF.

•

Disconnect EGR valve connector.

•

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

•

Is there malfunction?

Yes Repair or replace terminals, then go to Step 11.

No

Go to next step.

7

INSPECT EGR VALVE

•

Measure resistance between EGR valve 
terminals C and E (part-side).

•

Is resistance within 20—24 ohms?

Yes Go to next step.

No

Replace EGR valve, then go to Step 11.

8

INSPECT PCM CONNECTOR FOR POOR 
CONNECTION

•

Disconnect PCM connector.

•

Check for poor connection at terminal 68 
(damaged/pulled-out terminals, corrosion, 
etc.).

•

Is there malfunction?

Yes Repair terminal, then go to Step 11.

No

Go to next step.

9

INSPECT CONTROL CIRCUIT FOR SHORT

•

Check continuity between EGR valve terminal 
E (harness-side) and body ground.

•

Is there continuity?

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

Step 11.

No

Measure voltage between EGR valve terminal E and body 
ground.

•

If voltage is B+, repair or replace harness for short to 
power, then go to next step.

•

If voltage is approx. 0 V, go to next step.

10

INSPECT CONTROL CIRCUIT FOR OPEN 
CIRCUIT

•

Connect breakout box with PCM disconnected.

•

Check for continuity between EGR valve 
terminal E (harness-side) and breakout box 
terminal 68.

•

Is there continuity?

Yes Go to next step.

No

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

11

VERIFY TROUBLESHOOTING OF DTC P1496 
COMPLETED

•

Make sure to reconnect all disconnected 
connectors.

•

Turn ignition key to OFF then ON (Engine 
OFF).

•

Is same DTC present?

Yes Replace PCM, then go to next step.

No

Go to next step.

12

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

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

01–02B–137

01–02B

DTC P1497 [FS]

A3U010201083W06

Diagnostic procedure

DTC P1497

EGR valve stepping motor coil 2 open or short circuit

DETECTION 

CONDITION

•

PCM monitors input voltages from EGR valve coil control circuit just after turning ignition key to ON. If 
voltage at PCM terminal 72 remains low or high, PCM determines that EGR valve circuit has malfunction.

Diagnostic support note

•

This is a diagnostic support DTC (monitored once per key cycle).

•

MIL does not illuminate.

•

FREEZE FRAME DATA is not available.

•

DTC is not stored in PCM memory.

POSSIBLE 

CAUSE

•

EGR valve malfunction

•

Connector or terminal malfunction

•

Short to ground circuit in wiring between EGR valve terminal A and PCM terminal 72

•

Open circuit in wiring between EGR valve terminal A and PCM terminal 72

•

Short to power circuit in wiring between EGR valve terminal A and PCM terminal 72

•

Open circuit in wiring between main relay terminal D and EGR valve terminal C

•

PCM malfunction

STEP

INSPECTION

ACTION

1

VERIFY RELATED REPAIR INFORMATION 
AVAILABILITY

•

Check for related Service Bulletins availability.

•

Is any 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.

2

CLASSIFY INTERMITTENT CONCERN OR 
CONTINUOUS CONCERN

•

Turn ignition key to OFF then ON (Engine 
OFF).

•

Is same DTC present?

Yes Go to next step.

No

Refer to intermittent concern.
(See 01–03B–4 INTERMITTENT CONCERN 
TROUBLESHOOTING [FS].)

3

CLASSIFY POWER CIRCUIT OR CONTROL 
CIRCUIT MALFUNCTION

•

Is same DTC and P1496 present?

Yes Malfunction at EGR valve or power circuit.

Go to next step.

No

Malfunction at EGR valve or control circuit.
Go to Step 6.

1712-1U-01G(01-02B).fm  137 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–138

End Of Sie

4

INSPECT EGR VALVE FOR POOR 
CONNECTION

•

Turn ignition key to OFF.

•

Disconnect EGR valve connector.

•

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

•

Is there malfunction?

Yes Repair or replace terminals, then go to Step 11.

No

Go to next step.

5

INSPECT POWER CIRCUIT FOR OPEN 
CIRCUIT

•

Turn ignition key to ON (Engine OFF).

•

Measure voltage between EGR valve terminal 
C (harness-side) and body ground.

•

Is voltage B+?

Yes Inspect EGR valve coils 1 and 2.

(See 01–16–15 EGR VALVE INSPECTION.)

•

If there is a malfunction, replace EGR valve, and then 
go to Step 11.

•

If there is no malfunction, then go to Step 11.

No

Repair or replace harness for open circuit, then go to Step 
11.

6

INSPECT EGR VALVE FOR POOR 
CONNECTION

•

Turn ignition key to OFF.

•

Disconnect EGR valve connector.

•

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

•

Is there malfunction?

Yes Repair or replace terminals, then go to Step 11.

No

Go to next step.

7

INSPECT EGR VALVE

•

Measure resistance between EGR valve 
terminals C and A (part-side).

•

Is resistance within 20—24 ohms?

Yes Go to next step.

No

Replace EGR valve, then go to Step 11.

8

INSPECT PCM CONNECTOR FOR POOR 
CONNECTION

•

Disconnect PCM connector.

•

Check for poor connection at terminal 72 
(damaged/pulled-out terminals, corrosion, 
etc.).

•

Is there malfunction?

Yes Repair terminal, then go to Step 11.

No

Go to next step.

9

INSPECT CONTROL CIRCUIT FOR SHORT

•

Check continuity between EGR valve terminal 
A (harness-side) and body ground.

•

Is there continuity?

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

Step 11.

No

Measure voltage between EGR valve terminal A and body 
ground.

•

If voltage is B+, repair or replace harness for short to 
power, then go to next step.

•

If voltage is approx. 0 V, go to next step.

10

INSPECT CONTROL CIRCUIT FOR OPEN 
CIRCUIT

•

Connect breakout box with PCM disconnected.

•

Check for continuity between EGR valve 
terminal A (harness-side) and breakout box 
terminal 72.

•

Is there continuity?

Yes Go to next step.

No

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

11

VERIFY TROUBLESHOOTING OF DTC P1497 
COMPLETED

•

Make sure to reconnect all disconnected 
connectors.

•

Turn ignition key to OFF, then ON (Engine 
OFF).

•

Is same DTC present?

Yes Replace PCM, then go to next step.

No

Go to next step.

12

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

1712-1U-01G(01-02B).fm  138 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–139

01–02B

DTC P1498 [FS]

A3U010201083W07

Diagnostic procedure

DTC P1498

EGR valve stepping motor coil 3 open or short circuit

DETECTION 

CONDITION

•

PCM monitors input voltages from EGR valve coil control circuit just after turning ignition key to ON. If 
voltage at PCM terminal 46 remains low or high, PCM determines that EGR valve circuit has malfunction.

Diagnostic support note

•

This is a diagnostic support DTC (monitored once per key cycle).

•

MIL does not illuminate.

•

FREEZE FRAME DATA is not available.

•

DTC is not stored in PCM memory.

POSSIBLE 

CAUSE

•

EGR valve malfunction

•

Connector or terminal malfunction

•

Short to ground circuit in wiring between EGR valve terminal B and PCM terminal 46

•

Open circuit in wiring between EGR valve terminal B and PCM terminal 46

•

Short to power circuit in wiring between EGR valve terminal B and PCM terminal 46

•

Open circuit in wiring between main relay terminal D and EGR valve terminal D

•

PCM malfunction

STEP

INSPECTION

ACTION

1

VERIFY RELATED REPAIR INFORMATION 
AVAILABILITY

•

Check for related Service Bulletins availability.

•

Is any 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.

2

CLASSIFY INTERMITTENT CONCERN OR 
CONTINUOUS CONCERN

•

Turn ignition key to OFF then ON (Engine 
OFF).

•

Is same DTC present?

Yes Go to next step.

No

Refer to intermittent concern.
(See 01–03B–4 INTERMITTENT CONCERN 
TROUBLESHOOTING [FS].)

3

CLASSIFY POWER CIRCUIT OR CONTROL 
CIRCUIT MALFUNCTION

•

Is same DTC and P1499 present?

Yes Malfunction at EGR valve or power circuit.

Go to next step.

No

Malfunction at EGR valve or control circuit.
Go to Step 6.

1712-1U-01G(01-02B).fm  139 ページ  ２００１年６月２９日 金曜日 午後３時２４分