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Mazda Protege 5. Manual - part 114

SYMPTOM TROUBLESHOOTING [ENGINE CONTROL SYSTEM (FS)]

01–03B–49

01–03B

End Of Sie

NO.30 REFERENCE VOLTAGE [FS]

A3U010318881W35

Diagnostic procedure

•

Start engine.

•

Lightly tap on suspect component, wiggle
and pull each wire/connector at suspect
component or PCM.

•

Are any PID values out of range, or do they
suddenly change and go back into range?

Yes

Inspect each wire for corrosion, bent or loose terminal
crimps.

Go to next step.

•

Start engine.

•

Accurately spray water on suspect
component wire, component or vacuum line
related to possible fault area.

•

Are any PID values out of range, or suddenly
change and go back into range, or was there
a noticeable engine misfire/stumble?

Yes

Fault occurred while spraying on component:

•

Replace part and verify repair.

Fault occurred while spraying wiring:

•

Inspect each wire for corrosion, bent or loose
terminals and poor wire terminal crimps.

Fault occurred while spraying vacuum line:

•

Repair vacuum hoses.

Inspect wire and connector at suspect component for
corrosion, bent or loose terminals, poor wire terminal
crimps and high tension of wire.
Repair as necessary.

STEP

INSPECTION

RESULTS

ACTION

Reference voltage

DESCRIPTION

•

Incorrect reference voltage

POSSIBLE CAUSE

•

Reference voltage circuit malfunction

Note

•

TP sensor, EGR boost sensor and fuel tank pressure sensor use reference voltage.

STEP

INSPECTION

RESULTS

ACTION

•

Disconnect appropriate sensor connector
when reference voltage circuit inspection
failed.

•

Turn ignition key to ON.

•

Measure voltage between following
appropriate sensor connector terminals:
— Reference voltage terminal — GND

terminal

•

Is reference voltage greater than 6.0 V?

Yes

Go to Step 13.

Go to next step.

•

Is voltage across battery terminals greater
than 10.5 V?

Yes

Go to next step.

Inspect charging system.

•

Turn ignition key to LOCK.

•

Leave appropriate sensor connector
disconnected.

•

Measure voltage between battery positive
terminal and GND (between PCM and
appropriate sensor) circuit at appropriate
sensor connector.

•

Is voltage greater than 10.5 V and within
1.0 V of battery voltage?

Yes

Go to next step.

Go to Step 8.

Note

•

The purpose of this step is to determine if
WDS or equivalent is communicating with
PCM.

•

Turn ignition key to ON.

•

Attempt to access ECT PID.

•

Can ECT PID be accessed?

Yes

Go to Step 7.

Go to next step.

•

Turn ignition key to LOCK.

•

Disconnect TP sensor, EGR boost sensor,
FTP sensor and PCM connectors.

•

Turn ignition key to ON.

•

Measure voltage between PCM connector
terminals 71/97 and 24/51/76/77/103.

•

Is voltage greater than 10.5 V?

Yes

Go to next step.

Repair open circuit between PCM terminal 71/97 and
main relay.

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SYMPTOM TROUBLESHOOTING [ENGINE CONTROL SYSTEM (FS)]

01–03B–50

•

Leave TP sensor, EGR boost sensor, FTP
sensor and PCM connectors disconnected.

•

Measure resistance between PCM connector
terminals 90 and 24/51/76/77/103.

•

Is resistance greater than 10,000 ohms?

Yes

Inspect for reference voltage at suspect sensor
connector again.
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 and
repeat Step 6.

Repair constant voltage circuit short to GND.

•

Turn ignition key to LOCK.

•

Leave TP sensor disconnected.

•

Disconnect PCM connector.

•

Measure resistance between PCM connector
terminal 90 and constant voltage circuit at
appropriate sensor connector.

•

Is resistance less than 5.0 ohms?

Yes

Inspect for reference voltage at suspect sensor
connector again.
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 and
repeat Step 7.

Repair open constant voltage circuit.

Note

•

The purpose of this step is to determine if
WDS or equivalent is communicating with
PCM.

•

Reconnect TP sensor connector.

•

Turn ignition key to ON.

•

Attempt to access ECT PID.

•

Can ECT PID be accessed?

Yes

Go to next step.

Go to Step 11.

•

Are DTCs present for two or more sensors
connected to PCM terminal 91?

•

Sensor connected to PCM terminal 91:
— TP sensor (P0122, P0123, P1122, P1123)
— EGR boost sensor (P0106, P0107,

P0108)

— FTP sensor (P0452, P0453)
— ECT sensor (P0117, P0118, P0125)
— IAT sensor (P0111, P0112, P0113)
— HO2S (front) (P0130, P0134)
— HO2S (rear) (P0138, P0140)

Yes

Go to next step.

Repair open GND circuit to sensor where reference
voltage circuit inspection failed.

•

Turn ignition key to LOCK.

•

Disconnect WDS or equivalent from DLC-2.

•

Disconnect PCM connector.

•

Measure resistance between GND circuit at
appropriate sensor connector and PCM
connector terminal 91.

•

Is resistance less than 5.0 ohms?

Yes

Reconnect sensor connector.
Go to appropriate DTC test.

Repair open GND circuit.

•

Turn ignition key to LOCK.

•

Disconnect PCM connector.

•

Measure resistance between battery
negative terminal and PCM terminals 24/51/
76/77/103.

•

Is each resistance less than 5.0 ohms?

Yes

Go to next step.

Repair open GND circuit.

•

Turn ignition key to LOCK.

•

Measure resistance between GND circuit at
following sensor connector and GND:
— TP sensor
— EGR boost sensor
— FTP sensor
— ECT sensor
— IAT sensor
— HO2S sensor (front)
— HO2S sensor (rear)

•

Is each resistance less than 5.0 ohms?

Yes

GND circuits are okay.
Inspect for reference voltage at suspect sensor
connector again.

•

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 and
repeat Step 12.

Inspect for open GND circuit.

STEP

INSPECTION

RESULTS

ACTION

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SYMPTOM TROUBLESHOOTING [ENGINE CONTROL SYSTEM (FS)]

01–03B–51

01–03B

End Of Sie

NO.31 SPARK PLUG CONDITION [FS]

A3U010318881W36

Diagnostic procedure

•

Turn ignition key to LOCK.

•

Disconnect TP sensor, EGR boost sensor,
fuel tank pressure sensor and PCM
connectors.

•

Turn ignition key on.

•

Measure voltage between reference voltage
circuit at TP sensor connector and battery
negative terminal.

•

Is voltage less than 0.5 V?

Yes

Inspect for reference voltage at suspect sensor
connector again.

•

information is not available, replace PCM and
repeat Step 13.

Repair constant voltage circuit short to power in
harness.

STEP

INSPECTION

RESULTS

ACTION

Spark plug condition

DESCRIPTION

•

Incorrect spark plug condition

POSSIBLE CAUSE

Note

•

Inspecting spark plugs condition can determine whether problem is related to a specific cylinder or
possibly to all cylinders.

Wet/carbon is stuck on specific plug:

•

Spark—Weak, not visible

•

Air/fuel mixture—Excessive fuel injection volume

•

Compression—No compression, low compression

•

Faulty spark plug

Grayish white with specific plug:

•

Air/fuel mixture—Insufficient fuel injection volume

•

Faulty spark plug

Wet/carbon is stuck on all plugs:

•

Spark—Weak

•

Air/fuel mixture—Too rich

•

Compression—Low compression

•

Clogging in intake/exhaust system

Grayish white with all plugs:

•

Air/fuel mixture—Too lean

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

•

Remove all spark plugs.

•

Inspect each spark plug.

•

Is condition of spark plugs okay?

Yes

Troubleshooting completed.

Specific plug is wet or covered with carbon:

•

Go to next step.

Specific plug looks grayish white:

•

Go to Step 7.

All plugs are wet or covered with carbon:

•

Go to Step 9.

All plugs look grayish white:

•

Go to Step 15.

•

Are any of spark plug wet/covered with
carbon from engine oil?

Yes

Working up and down, inspect all areas related to oil.

Go to next step.

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SYMPTOM TROUBLESHOOTING [ENGINE CONTROL SYSTEM (FS)]

01–03B–52

•

Inspect spark plug for following.
— Cracked insulator
— Heating value
— Air gap
— Worn electrode

•

Are spark plugs okay?

Yes

Go to next step.

Replace spark plug.

•

Inspect compression pressure at suspected
faulty cylinder.

•

Is compression pressure correct?
(See 01–10B–8 COMPRESSION
INSPECTION [FS].)

Yes

Go to next step.

Repair or replace malfunctioning part.

•

Install all spark plugs.

•

Carry out spark test at suspected faulty
cylinder.

•

Is strong blue spark visible? (Compare with
normal cylinder.)

Yes

Go to next step.

Repair or replace malfunctioning part.

•

Perform fuel line pressure inspection.
(See 01–14–28 PRESSURE REGULATOR
INSPECTION.)

•

Is fuel line pressure okay?

Yes

Inspect fuel injector for following:

•

Open or short in injector

•

Leakage

•

Injection volume

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.

•

Inspect spark plugs for following.
— Heating value
— Air gap

•

Are they okay?

Yes

Go to next step.

Replace spark plug.

•

Remove suspected fuel injector.

•

Inspect following:
— Resistance

(See 01–14–24 Resistance Inspection.)

— Fuel injection volume

(See 01–14–24 FUEL INJECTOR

INSPECTION.)

•

Are all above items okay?

Yes

Inspect for open circuit between suspected fuel injector
connector terminal and PCM connector following
terminals:

•

For #1 cylinder: 75

•

For #2 cylinder: 101

•

For #3 cylinder: 74

•

For #4 cylinder: 100

Replace fuel injector.

•

Is air cleaner element free of restrictions?

Yes

Go to next step.

Replace air cleaner element.

•

Carry out spark test.

•

Is strong blue spark visible at each cylinder?

Yes

Go to next step.

Repair or replace malfunctioning part.

•

Carry out fuel line pressure inspection

•

Is fuel line pressure correct?

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

, 37—45 psi}

Yes

Go to next step.

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.

•

Inspect following PIDs.
— ECT
— O2S11
— O2S12
— MAF

•

Are PIDs okay?

Yes

Go to next step.

Repair or replace malfunctioning part.

•

Inspect purge solenoid valve. (When the
engine can be started)

•

Is purge solenoid valve okay?

Yes

Go to next step.

Repair or replace malfunctioning part.

STEP

INSPECTION

RESULTS

ACTION

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