Mazda Protege 5. Manual - part 108

SYMPTOM TROUBLESHOOTING [ENGINE CONTROL SYSTEM (FS)]

01–03B–25

01–03B

End Of Sie

13

•

Connect WDS or equivalent to DLC-2.

•

Start engine and run it at idle.

•

Access LONG FT1 PID.

•

Measure LONG FT1 PID at idle.

•

Is PID value between -15% and +15%?

Yes

Go to next step.

No

LONG FT1 PID is out of specification.
Less than specification (too rich):

•

Inspect evaporative emission control system.

•

If system is okay, go to Step 15.

Greater than specification (too lean):

•

Inspect for air leakage at intake-air system 
components.

•

If system okay, go to next step.

14

•

Disconnect vacuum hose between purge 
solenoid valve and intake manifold from 
purge solenoid valve side.

•

Plug opening end of vacuum hose.

•

Start engine.

•

Does engine condition improve?

Yes

Inspect if purge solenoid valve is stuck open 
mechanically.
Inspect evaporative emission control system.

No

Go to next step.

15

•

Remove and shake PCV valve.

•

Does PCV valve rattle?

Yes

Go to next step.

No

Replace PCV valve.

16

•

Is there any restriction in exhaust system?

Yes

Inspect exhaust system.

No

Go to next step.

17

•

Visually inspect CMP sensor and projections 
of camshaft pulley.

•

Are CMP sensor and projections of camshaft 
pulley okay?

Yes

Go to next step.

No

Replace malfunctioning parts.

18

•

Inspect engine condition while tapping EGR 
valve housing.

•

Does engine condition improve?

Yes

Replace EGR valve.

No

Go to next step.

19

•

Is engine compression correct?

Yes

Inspect valve timing.

No

Inspect for causes.

20

•

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

•

If vehicle is repaired, troubleshooting 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–26

NO.9 FAST IDLE/RUNS ON [FS]

A3U010318881W14

Diagnostic procedure

End Of Sie

NO.10 LOW IDLE/STALLS DURING DECELERATION [FS]

A3U010318881W15

Diagnostic procedure

9

Fast idle/runs on

DESCRIPTION

•

Engine speed continues at fast idle after warm-up.

•

Engine runs after ignition key is turned to OFF.

POSSIBLE CAUSE

•

ECT sensor malfunction

•

Air leakage from intake-air system

•

Throttle body malfunction

•

Accelerator cable free play misadjustment

•

Cruise actuator cable misadjustment

STEP

INSPECTION

RESULTS

ACTION

1

•

Connect WDS or equivalent to DLC-2.

•

Access ECT PID.

•

Start and warm-up engine to normal 
operating temperature.

•

Is ECT PID reading between 82—112

°°°°

C 

{180—234

°°°°

F}?

Yes

Go to next step.

No

ECT PID is higher than 112

°°°°

C {234

°°°°

F}:

•

Go to symptom troubleshooting “NO.17 COOLING 
SYSTEM CONCERNS — OVERHEATING [FS].”

ECT PID is less than 82

°°°°

C {180

°°°°

F}:

•

Go to symptom troubleshooting “NO.18 COOLING 
SYSTEM CONCERNS - RUNS COLD [FS].”

2

•

Connect WDS or equivalent to DLC-2.

•

Turn ignition key to ON.

•

Retrieve any DTC.

•

Is “DTC” displayed?

Yes

DTC displayed:

•

Go to appropriate DTC test.

No

No DTC displayed:

•

Go to next step.

3

•

Is there air leakage felt or heard at intake-air 
system components while racing engine to 
higher speed?

Yes

Repair or replace parts as necessary.

No

Inspect accelerator cable free play.
(See 01–13B–17 ACCELERATOR CABLE 
INSPECTION [FS].)

4

•

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

•

If vehicle is repaired, troubleshooting completed.

•

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

10

Low idle/stalls during deceleration

DESCRIPTION

•

Engine stops unexpectedly at beginning of deceleration or recovery from deceleration.

POSSIBLE CAUSE

•

Vacuum leakage

•

IAC valve malfunction

•

Air leakage from intake-air system

•

TP sensor or related circuit malfunction

•

MAF sensor or related circuit malfunction

•

Brake switch or related circuit malfunction

•

Neutral/clutch switch or related circuit malfunction (MTX)

STEP

INSPECTION

RESULTS

ACTION

1

•

Does engine idle rough?

Yes

Go to symptom troubleshooting “NO.8 ENGINE RUNS 
ROUGH/ROLLING IDLE [FS].”

No

Go to next step.

2

•

Inspect for following:
— Proper routing and no damage of vacuum 

lines

— IAC valve is connected properly.
— No air leakage from intake-air system

•

Are all items okay?

Yes

Go to next step.

No

Service as necessary.
Repeat Step 2.

3

•

Connect WDS or equivalent to DLC-2.

•

Turn ignition key to ON.

•

Retrieve any DTC.

•

Is “DTC” displayed?

Yes

No DTC displayed:

•

Go to next step.

No

DTC displayed:

•

Go to appropriate DTC test.

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SYMPTOM TROUBLESHOOTING [ENGINE CONTROL SYSTEM (FS)]

01–03B–27

01–03B

End Of Sie

4

•

Does idle speed drop or stall when 
disconnecting IAC valve?

Yes

Go to next step.

No

Inspect following:

•

Circuit from IAC valve to PCM connector terminal 
54 or 83 for open and short

•

IAC valve for sticking

If okay, go to next step.

5

•

Disconnect vacuum hose between purge 
solenoid valve and intake manifold from 
purge solenoid valve side.

•

Plug opening end of vacuum hose.

•

Drive vehicle.

•

Does engine condition improve?

Yes

Inspect evaporative emission control system.

No

Go to next step.

6

•

Connect WDS or equivalent to DLC-2.

•

Access TP, MAF , VSS PIDs.

•

Monitor each PID while driving vehicle.

•

Are PIDs okay?

Yes

Go to symptom troubleshooting “NO.29 
INTERMITTENT CONCERNS [FS].”

No

TP PID: Inspect TP sensor.
MAF PID: Inspect MAF sensor.
VSS PID: Inspect VSS.

7

•

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

•

If vehicle is repaired, troubleshooting 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–28

NO.11 ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE, 
SURGES [FS]

A3U010318881W16

Diagnostic procedure

11

Engine stalls/quits — Acceleration/cruise
Engine runs rough — Acceleration/cruise
Misses — Acceleration/cruise
Buck/jerk — Acceleration/cruise/deceleration
Hesitation/stumble — Acceleration
Surges — Acceleration/cruise

DESCRIPTION

•

Engine stops unexpectedly at beginning of acceleration or during acceleration.

•

Engine stops unexpectedly while cruising.

•

Engine speed fluctuates during acceleration or cruising.

•

Engine misses during acceleration or cruising.

•

Vehicle bucks/jerks during acceleration, cruising or deceleration.

•

Momentary pause at beginning of acceleration or during acceleration

•

Momentary minor irregularity in engine output

POSSIBLE CAUSE

•

A/C system improper operation

•

Erratic signal or no signal from CMP sensor

•

Air leakage from intake-air system parts

•

Purge solenoid valve malfunction

•

IAC valve improper operation

•

EGR valve malfunction

•

Erratic signal from CKP sensor

•

Low engine compression

•

Vacuum leakage

•

Poor fuel quality

•

Spark leakage from high-tension leads

•

Air cleaner restriction

•

PCV valve malfunction

•

Improper valve timing due to jumping out of timing belt

•

Restriction in exhaust system

•

Intermittent open or short in fuel pump circuit

•

Inadequate fuel pressure

•

Fuel pump mechanical malfunction

•

Fuel leakage from fuel injector

•

Fuel injector clogging

•

Intermittent open or short of MAF sensor, throttle position sensor and VSS

•

ATX malfunction

•

Clutch slippage

Warning
The following troubleshooting flow chart contains fuel system diagnosis and repair 
procedures. Read following warnings before performing fuel system services:

••••

Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always 
keep sparks and flames away from fuel.

••••

Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or 
death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete 
“BEFORE REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this 
manual.
(See 01–14–4 BEFORE REPAIR PROCEDURE.)
(See 01–14–5 AFTER REPAIR PROCEDURE.)

STEP

INSPECTION

RESULTS

ACTION

1

•

Inspect for following:
— Vacuum connection
— Air cleaner element
— No air leakage from intake-air system
— No restriction of intake-air system
— Proper sealing of intake manifold and 

components attached to intake manifold: 
EGR valve, IAC valve

— Ignition wiring
— Fuel quality: proper octane, 

contamination, winter/summer blend

— Electrical connections
— Smooth operation of throttle

•

Are all items okay?

Yes

Go to next step.

No

Service as necessary.
Repeat Step 1.

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