Mazda CX 7. Manual - part 78

SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–9

01-03

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Possible factor

Troubleshooting item

Melting of main or other fuses

MIL illuminates

Will not crank

Hard  start/long crank/erratic start/erratic crank

Engine stalls

After start/at idle

Cranks normally but will not start

Slow return to idle

Engine runs rough/rolling idle

Fast/idle runs on

Low idle/stalls during deceleration

Engine stalls/quits

Engine runs rough

Misses

Buck/jerk

Hesitation/stumble

Surges

Acceleration/cruise

Acceleration/cruise/
deceleration

Acceleration/cruise

Acceleration/cruise

Acceleration/cruise

Acceleration/cruise

Poor fuel economy

Emission compliance

High oil consumption/leakage

Cooling system concerns

Cooling system concerns

Overheating

Runs cold

Exhaust smoke

Fuel odor (in engine compartment)

Engine noise

Vibration concerns (engine)

A/C does not work sufficiency

A/C  always on or A/C compressor 
runs continuously.

  A/C does not cut off under wide open throttle 

Exhaust sulphur smell

Fuel refill concerns

Fuel filling shut off issues

Spark plug condition

Knocking/pinging

Lack/loss of power

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24

X: Applied

Engine or tr

ansaxle mounts are improper

ly installed.

Improper engine oil viscosity

Improper v

alv

e timing

Fuel quality

Cooling f

an or condenser f

an seats are improper

.

Coolant leakage (inter

nal, turbocharger

, e

xter

nal)

V

a

riab

le tumb

le control system malfunction

Air cleaner element clogging or restr

iction

Air suction in intak

e-air system

Intak

e-air system restr

iction

Air leakage from intak

e-air system (loose 

tubes

, cr

ac

ks

, gask

ets b

loc

kage)

V

a

riab

le v

alv

e timing system malfunction

Oil leakage (inter

nal, turbocharger

, e

xter

nal)

Improper oil or fluid le

v

e

l

Engine o

v

erheating

Acceleration/cruise

Acceleration/cruise

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SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–10

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Possible factor

Troubleshooting item

Melting of main or other fuses

MIL illuminates

Will not crank

Hard  start/long crank/erratic start/erratic crank

Engine stalls

After start/at idle

Cranks normally but will not start

Slow return to idle

Engine runs rough/rolling idle

Fast/idle runs on

Low idle/stalls during deceleration

Engine stalls/quits

Engine runs rough

Misses

Buck/jerk

Hesitation/stumble

Surges

Acceleration/cruise

Acceleration/cruise/
deceleration

Acceleration/cruise

Acceleration/cruise

Acceleration/cruise

Acceleration/cruise

Poor fuel economy

Emission compliance

High oil consumption/leakage

Cooling system concerns

Cooling system concerns

Overheating

Runs cold

Exhaust smoke

Fuel odor (in engine compartment)

Engine noise

Vibration concerns (engine)

A/C does not work sufficiency

A/C  always on or A/C compressor 
runs continuously.

  A/C does not cut off under wide open throttle 

Exhaust sulphur smell

Fuel refill concerns

Fuel filling shut off issues
Spark plug condition

Knocking/pinging

Lack/loss of power

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24

X: Applied

Electronic throttle control improper oper

ation

Fuel pump (lo

w-pressure side) malfunction (Mechanically 

or electr

ically)

Improper oper

ation of w

astegate system

Pressure regulator (b

uilt-in fuel pump unit at fuel tank)

Inadequate fuel pressure (High-pressure side)

Inadequate fuel pressure (Lo

w-pressure side)

Fuel line restr

iction or clogging

Ignition coil malfunction (e

.g.

 open, shor

t or cr

ac

ks)

Initial ignition timing misadjustment (CKP and pulse wheel 

misadjustment)

Charge air cooler malfunction

Spar

k plug malfunction

T

urbocharger malfunction

V

acuum leakage (V

acuum hose damage

, misrouting)

Throttle body malfunction

Acceleration/cruise

Acceleration/cruise

acxuuw00000312

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SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–11

01-03

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Possible factor

Troubleshooting item

Melting of main or other fuses

MIL illuminates

Will not crank

Hard  start/long crank/erratic start/erratic crank

Engine stalls

After start/at idle

Cranks normally but will not start

Slow return to idle

Engine runs rough/rolling idle

Fast/idle runs on

Low idle/stalls during deceleration

Engine stalls/quits

Engine runs rough

Misses

Buck/jerk

Hesitation/stumble

Surges

Acceleration/cruise

Acceleration/cruise/
deceleration

Acceleration/cruise

Acceleration/cruise

Acceleration/cruise

Acceleration/cruise

Poor fuel economy

Emission compliance

High oil consumption/leakage

Cooling system concerns

Cooling system concerns

Overheating

Runs cold

Exhaust smoke

Fuel odor (in engine compartment)

Engine noise

Vibration concerns (engine)

A/C does not work sufficiency

A/C  always on or A/C compressor 
runs continuously.

  A/C does not cut off under wide open throttle 

Exhaust sulphur smell

Fuel refill concerns

Fuel filling shut off issues

Spark plug condition

Knocking/pinging

Lack/loss of power

1
2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

20

21

22

23

25

26

27

28

29

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19

24

X: Applied

Fuel filters restriction or clogging

Fuel injector malfunction (inoperative)

Fuel pump resister or related circuit malfunction

Improper air/fuel ratio mixture control

Exhaust 

system or catalytic converter restriction

EGR system malfunction

EVAP control system malfunction

PCV valve malfunction

Fuel leakage at fuel line

High pressure fuel pump malfunction

Fuel pressure limiter malfunction (b

uilt-in common r

ail)

Spill v

alv

e control solenoid v

alv

e malfunction (b

uilt-in high 

pressure fuel pump)

Incorrect fuel injection timing or amount

Catalytic con

v

e

rter malfunction

Exhaust gas leakage

Acceleration/cruise

Acceleration/cruise

acxuuw00000313

1871-1U-06B(01-03).fm  11 ページ  ２００６年３月１５日　水曜日　午前１０時３６分

SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–12

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Possible factor

Troubleshooting item

Melting of main or other fuses

MIL illuminates

Will not crank

Hard  start/long crank/erratic start/erratic crank

Engine stalls

After start/at idle

Cranks normally but will not start

Slow return to idle

Engine runs rough/rolling idle

Fast/idle runs on

Low idle/stalls during deceleration

Engine stalls/quits

Engine runs rough

Misses

Buck/jerk

Hesitation/stumble

Surges

Acceleration/cruise

Acceleration/cruise/
deceleration

Acceleration/cruise

Acceleration/cruise

Acceleration/cruise

Acceleration/cruise

Poor fuel economy

Emission compliance

High oil consumption/leakage

Cooling system concerns

Cooling system concerns

Overheating

Runs cold

Exhaust smoke

Fuel odor (in engine compartment)

Engine noise

Vibration concerns (engine)

A/C does not work sufficiency

A/C  always on or A/C compressor 
runs continuously.

  A/C does not cut off under wide open throttle 

Exhaust sulphur smell

Fuel refill concerns

Fuel filling shut off issues

Spark plug condition

Knocking/pinging

Lack/loss of power

1
2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

20

21

22

23

25

26

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17

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19

24

X: Applied

Nonretur

n v

alv

e malfunction

Fuel shut off v

alv

e malfunction

No batter

y po

w

er supply to PCM

P

oor PCM g

round or v

ehicle g

round (open)

Electr

ical connector disconnection

ECT sensor or related circuit malfunction

Br

ak

e s

witch or related circuit malfunction

F

ront or rear HO2S sensor or related circuit malfunction 

Fuel pressure sensor or related circuit malfunction  

MAP sensor or related circuit malfunction  

IA

T sensor 1 (integ

rated in MAF sensor) or related circuit 

malfunction  

Boost air temper

ature sensor (integ

rated in MAP sensor) 

or related circuit malfunction  

Constant v

oltage supply circuit malfunction

Main rela

y malfunction (mechanically or electr

ically)

Acceleration/cruise

Acceleration/cruise

acxuuw00000314

1871-1U-06B(01-03).fm  12 ページ  ２００６年３月１５日　水曜日　午前１０時３６分