Mazda Protege 5. Manual - part 179

CONTROL SYSTEM [FS]

01–40B–25

01–40B

IAC signal

•

PCM terminal: 83(+)-103(-)

•

Oscilloscope setting: 2 V/DIV(Y), 0.5 ms/DIV(X), 
DC range

•

Vehicle condition: idle after warm up

SGC signal

•

PCM terminal: 85(+)-86(-)

•

Oscilloscope setting: 1 V/DIV(Y), 10 ms/DIV(X), 
AC range

•

Vehicle condition: idle after warm up

Shift solenoid B cointrol signal

•

PCM terminal: 99(+)-103(-)

•

Oscilloscope setting: 5 V/DIV(Y), 5ms/DIV(X), DC 
range

•

Vehicle condition: Drive in D range, 1st gear

Shift solenoid C cointrol signal

•

PCM terminal: 102(+)-103(-)

•

Oscilloscope setting: 5 V/DIV(Y), 5 ms/DIV(X), 
DC range

•

Vehicle condition: Drive in 1st or 2nd gear

End Of Sie

Z3U0140W017

Z3U0140W032

Z3U0140W016

Z3U0140W016

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CONTROL SYSTEM [FS]

01–40B–26

INSPECTION USING AN OSCILLOSCOPE (REFERENCE) [FS]

A3U014018881W04

Purpose
The use of oscilloscope makes the inspection of a 
part such as a stuck solenoid value possible without 
actually removing parts.

When Normal
Counter electromotive voltage A, generated when the 
three-way solenoid valve or the fuel injector is turned 
off from on, shows irregular convergence because 
induced electromotive voltage B, generated by the 
plunger return operation, is added to it.

When Plunger Stuck
When the plunger is stuck, pulse convergence is 
smooth because no induced electromotive voltage B 
is generated.

End Of Sie

X3U101WNT

X3U101WNU

X3U101WNV

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CONTROL SYSTEM [FS]

01–40B–27

01–40B

INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTION [FS]

A3U014018845W01

Resistance Inspection

Note

•

Perform the following test only when directed.

1. Remove the IAT sensor.
2. Measure the resistance of the IAT sensor terminals A and B using an ohmmeter.

•

If not as specified, replace the IAT sensor.

•

If IAT sensor is okay, but PID value or PCM terminal 39 voltage is out of specification, carry out the “Circuit 
Open/Short Inspection”.

Specification

IAT sensoir signal characteristic (reference)

Circuit Open/Short Inspection

1. Disconnect the PCM connector. (See 01–40B–7 PCM REMOVAL/INSTALLATION [FS].)
2. Connect the SST (104 Pin Breakout Box) to the 

PCM as shown.

3. Tighten the connector attaching screw.

Tightening torque

7.9—10.7 N·m
{80—110 kgf·cm, 69.5—95.4 in·lbf}

4. Inspect for an open or short circuit in the following 

wiring harnesses by probing the applicable 
sensor and SST (104 Pin Breakout Box) terminals 
with ohmmeter leads.

•

If there is an open or short circuit, repair or 
replace wiring harnesses.

•

If there is no open or short circuit, replace the IAT sensor.

Open circuit

•

IAT signal circuit (IAT sensor connector terminal A and PCM connector terminal 39)

•

GND circuit (IAT sensor connector terminal B and PCM connector terminal 91)

Ambient temperature (

°°°°

C {

°°°°

F})

Resistance (kilohm)

20 {68}

2.0—2.9

80 {176}

0.27—0.37

Z3U0140W021

X3U140WE8

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CONTROL SYSTEM [FS]

01–40B–28

Short circuit

•

IAT signal circuit (IAT sensor connector 
terminal A and PCM connector terminal 39 to 
GND)

5. Install the IAT sensor.

End Of Sie

MASS AIR FLOW (MAF) SENSOR INSPECTION [FS]

A3U014013210W01

Note

•

Perform the following test only when directed.

1. Visually inspect for damage, cracks, terminal bends and terminal rust on the MAF sensor.

•

If any of the above is found, replace the MAF sensor.

•

If the MAF sensor is okay, but PID value or PCM terminal 88 voltage is out of specification, carry out the 
“Circuit Open/Short Inspection”.

Circuit Open/Short Inspection

1. Remove the PCM. (See 01–40B–7 PCM REMOVAL/INSTALLATION [FS].)
2. Connect the SST (104 Pin Breakout Box) to the 

PCM as shown.

3. Tighten the connector attaching screw.

Tightening torque

7.9—10.7 N·m
 {80—110 kgf·cm, 69.5—95.4 in·lbf}

4. Inspect for an open or short circuit in the following 

wiring harnesses by probing the applicable 
sensor and SST (104 Pin Breakout Box) terminals 
with ohmmeter leads.

•

If there is an open or short circuit, repair or 
replace wiring harnesses.

•

If there is no open or short circuit, replace the MAF sensor.

Open circuit

•

MAF signal circuit (MAF sensor connector terminal B and PCM connector terminal 88)

•

Power circuit (MAF sensor connector terminal C and main relay terminal D through common connector)

•

GND circuit (MAF sensor connector terminal A and PCM connector terminal 103 through common 
connector)

Y3U140WB1

X3U140WE8

Y3U140WB2

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