Mazda Protege 5. Manual - part 115

SYMPTOM TROUBLESHOOTING [ENGINE CONTROL SYSTEM (FS)]

01–03B–53

01–03B

End Of Sie

14

•

Carry out compression inspection.

•

Is compression correct?

Yes

Inspect for clogging in exhaust system.

No

Repair or replace malfunctioning part.

15

•

When engine cannot be started, inspect 
intake-air system for air leakage.

•

When engine can be started, carry out intake 
manifold vacuum inspection.

•

Is air sucked in from intake-air system?

Yes

Repair or replace malfunctioning part.

No

Go to next step.

16

•

Carry out fuel line pressure inspection.

•

Is fuel line pressure correct?

Fuel line pressure
260—310 kPa {2.6—3.2 kgf/cm

2

, 37—45 psi}

Yes

Inspect following PIDs.

•

ECT

•

O2S11

•

O2S12

•

MAF

Inspect PCM GND condition.

No

Zero or low:

•

Inspect fuel pump circuit.

•

Inspect open for fuel pump relief valve.

•

Inspect for fuel leakage inside pressure regulator.

•

Inspect for clogged main fuel line.

•

Inspect pulsation damper.

High:

•

Inspect pressure regulator for high pressure cause.

•

Inspect for clogged fuel return line.

17

•

Verify test results.
— If okay, return to diagnostic index to service any additional symptoms.
— If malfunction remains, inspect related Service Bulletins and perform repair or diagnosis.

•

If vehicle is repaired, troubleshooting is completed.

•

If vehicle is not repaired or additional diagnostic information is not available, replace PCM.

STEP

INSPECTION

RESULTS

ACTION

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SYMPTOM TROUBLESHOOTING [ENGINE CONTROL SYSTEM (FS)]

01–03B–54

ENGINE CONTROL SYSTEM OPERATION INSPECTION [FS]

A3U010318881W37

Evaporative System Leak Inspection Using Leak Tester

1. Perform the following SST (Evaporative Emission System Tester MZ254AT3641) self-test:

Note

•

If the tester does not work correctly during self-test, refer to the tester operators manual for more detailed 
self test procedures.

(1) Verify the gas cylinder valve is closed and the control valve located on the tester is in the TEST position. All 

tester displays should be off at this time.

(2) Connect the long hose (part of SST) to the tester.
(3) Connect the manifold assembly (part of SST) 

to the long hose as shown.

(4) Open the gas cylinder valve and verify the 

gas cylinder regulator left gauge reads 10 to 
12 psi (preset at factory).

•

If not, refer to the tester operators manual 
to contact tester manufacturer.

(5) Press the ON/OFF switch to turn on the SST 

and make sure the left display reads 0.0.

(6) Turn the control valve on the tester to the 

FILL position.

(7) Verify the left display reading is within 13.9 to 

14.0 inches of water.

•

If not, adjust the pressure using the 
regulator knob located on the right side of the tester.

(8) Turn the control valve to TEST position and press the START switch.
(9) After the 2-minute countdown (left display) is completed, the right display shows the total pressure loss for 

that period. A 0.5 inch of water loss is acceptable on the self-test.

•

If the loss is more than 0.5 inch of water, do one or more self-test. If the failed test repeats, check for 
leak using the ultrasonic leak detector (part of SST).

2. Press the RESET switch to set the left display reading to 0.0.
3. Connect the fuel cap test adapter (part of SST) to the manifold assembly and fuel-filler cap from the vehicle.

•

If the fuel-filler cap is not a genuine part, replace it.

4. Connect the threaded test adapter (part of SST) 

to the manifold assembly and fuel-filler neck.

5. Connect the WDS or equivalent to DLC-2.
6. Turn the ignition key to ON (engine OFF).
7. Close the canister drain cut valve (CDCV) using 

ON BOARD DEVICE CONTOROL function.

Note

•

The CDCV is closed for 10 minutes unless 
the following any action is done:
— The engine is started.
— The ignition key is turned to OFF.
— The fuel tank pressure sensor signal 

exceeds 6.43 kPa {48.3 mmHg, 1.9 
inHg}.

8. Turn the control valve to the FILL position.
9. Wait (maximum 40 seconds) until the left display reads 13.5 to 14 inches of water.

•

If the reading is slightly below, adjust it using the regulator knob.

•

If the reading is far below, the EVAP system has large leak. Check for leak (using the ultrasonic leak 
detector if necessary) and repair.

10. Turn the control valve to the TEST position and press the START switch.
11. After the 2-minute countdown (left display) is completed, check the test result (the failed/passed light on the 

tester).

•

If the green light turns on, the EVAP system is OK.

•

If the red light turns on, the EVAP system has leakage. Check for leak using the ultrasonic leak detector) 
and repair.

12. Close the gas cylinder valve.
13. Turn the control valve to the FILL position.
14. Press the ON/OFF switch to turn off the tester.

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SYMPTOM TROUBLESHOOTING [ENGINE CONTROL SYSTEM (FS)]

01–03B–55

01–03B

Evaporative System Leak Inspection Using Vacuum Pump
Whole system inspection

1. Disconnect the vacuum hose between the purge solenoid valve and the catch tank from the purge solenoid 

valve.

2. Insert hose on the vacuum pump.
3. Connect WDS or equivalent to DLC-2.
4. Turn ignition key to ON (Engine OFF).
5. Close the canister drain cut valve (CDCV) using ON BOARD DEVICE CONTROL function.

Note

•

The CDCV is closed for 10 minutes unless the following any action is done:
— The engine is started.
— The ignition key is turned to OFF.
— The fuel tank pressure sensor signal exceeds 6.43 kPa {48.3 mmHg, 1.9 inHg}.

6. Apply 1.7 kPa vacuum and monitor FTP output voltage.
7. Verify that the voltage holds at the specified readings for a minimum of 2 minites.

•

If the voltage does not hold, inspect the fuel tank pressure sensor.

•

If the fuel tank pressure sensor is okay, carry out the “Inspection from charcoal canister to fuel tank”.

Inspection from charcoal canister to fuel tank

1. Inspect for loose and wrongly connected hoses between the charcoal canister and the fuel tank. (See 01–16–2 

EMISSION SYSTEM LOCATION INDEX.)

2. Disconnect the vacuum hose between the charcoal canister and the fuel tank from the charcoal canister.
3. Insert hose on the vacuum pump.
4. Apply 1.7 kPa vacuum.
5. Verify that the vacuum holds at the specified readings for a minimum of 2 minites.

•

If the vacuum does not hold, inspect the fuel tank, related vacuum hoses and fuel-filler cap.

•

If the the fuel tank, related vacuum hoses and fuel-filler cap are okay, carry out the “Inspection from 
charcoal canister to fuel tank”.

Inspection from charcoal canister to purge solenoid valve

1. Inspect for loose and wrongly connected hoses between the charcoal canister and the purge solenoid valve. 

(See 01–16–2 EMISSION SYSTEM LOCATION INDEX.)

2. Disconnect the vacuum hose between the charcoal canister and the catch tank from the charcoal canister.
3. Insert hose on the vacuum pump.
4. Apply 3.3 kPa {25 mmHg, 1.0 inHg} vacuum. Vacuum should hold at the specified readings for a minimum of 

2 minutes.

•

If the vacuum does not hold, inspect the following:
— Catch tank for plugging, damages and pinhole using vacuum pump
— Purge solenoid valve (See 01–16–12 PURGE SOLENOID VALVE INSPECTION.)
— Charcoal canister for damage and pinhole (See 01–16–9 CHARCOAL CANISTER INSPECTION.)
— CDCV for damage and leakage (See 01–16–10 CANISTER DRAIN CUT VALVE (CDCV) 

INSPECTION .)

— Detached, incorrectly installed or cracked hose from charcoal canister to CDCV

Main Relay Operation Inspection

1. Verify that the main relay clicks when the ignition 

key is turned to ON and LOCK.

2. If there is no operation sound, inspect the 

following:

•

Main relay

•

Harness and connector between ignition key 
and main relay

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SYMPTOM TROUBLESHOOTING [ENGINE CONTROL SYSTEM (FS)]

01–03B–56

Intake Manifold Vacuum Inspection

1. Verify air intake hoses are installed properly.
2. Start the engine and run it at idle.
3. Measure the intake manifold vacuum using a vacuum gauge.

•

If not as specified, inspect the following:
— Air suction at throttle body, intake manifold and PCV valve installation points
— Fuel injector insulator
— Accelerator cable free play
— Engine compression (See 01–10B–8 COMPRESSION INSPECTION [FS].)

Specification

More than 60 kPa {450 mmHg, 18 inHg}

Note

•

Air suction can be located by engine speed 
change when lubricant is sprayed on the 
area where suction is occurring.

Idle Air Control (IAC) Inspection
Engine coolant temperature compensation inspection

1. Connect the WDS or equivalent to DLC-2.
2. Select the following PIDs.

•

ECT

•

RPM

3. Verify that the engine is in cold condition, then start the engine.
4. Verify that the engine speed decreases as the engine warms up.

•

If the engine speed does not decrease or decreases slowly, carry out the following:
— ECT sensor inspection
— IAC valve inspection

Load compensation inspection

1. Warm up the engine to normal operating temperature and run it at idle.
2. Connect the WDS or equivalent to DLC-2.
3. Select the following PID.

•

RPM

4. Turn the electrical loads on and verify that the engine speed is within the specification.

•

If not as specified, carry out the following:
— A/C switch inspection
— P/S pressure switch inspection
— IAC valve inspection

Engine speed (rpm)

*

: Neutral or P position

Note

•

Excludes temporary idle speed drop just after the loads are turned on.

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Load condition

Idle-up speed (rpm)*

No load

650—750 (700

±

50)

Headlight switch is on.

P/S on

700—800 (750

±

50)

A/C on

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