Inspection Using An Oscilloscope (Reference)

NOTE:

The duty ratio for the wave pattern can vary with the control conditions. Therefore determine comprehensively where the malfunction occurs among the input systems, output systems, and the PCM.

Throttle control (+)

Fig 1: View Of Throttle Control (+) Wave Pattern

G05981104

Courtesy of MAZDA MOTORS CORP.

Terminal connected: 2A (+)-Negative battery terminal
Oscilloscope setting: 5 V/DIV (Y): 0.4 ms/DIV (X), DC range
Measurement condition: IG SW ON

Throttle control (-)

Fig 2: View Of Throttle Control (-) Wave Pattern

G05981105

Courtesy of MAZDA MOTORS CORP.

Terminal connected: 2B (+)-Negative battery terminal
Oscilloscope setting: 5 V/DIV (Y): 1 ms/DIV (X), DC range
Measurement condition: As soon as the accelerator pedal is fully released from the fully depressed position while the ignition switch is at ON (engine off.)

Purge control

Fig 3: View Of Purge Control Wave Pattern

G05981106

Courtesy of MAZDA MOTORS CORP.

Terminal connected: 2C (+)-Negative battery terminal
Oscilloscope setting: 5 V/DIV (Y): 20 ms/DIV (X), DC range
Measurement condition: Idling after warm-up (no load)

NOTE:

Purge control might not be activated depending on the engine conditions.

APV motor control (+)

Fig 4: View Of APV Motor Control (-) Wave Pattern

G05981107

Courtesy of MAZDA MOTORS CORP.

Terminal connected: 2D (+)-Negative battery terminal
Oscilloscope setting: 5 V/DIV (Y): 20 ms/DIV (X), DC range
Measurement condition: High engine speed after warm-up

OCV control

Fig 5: View Of OCV Control Wave Pattern

G05981108

Courtesy of MAZDA MOTORS CORP.

Terminal connected: 2E (+)-Negative battery terminal
Oscilloscope setting: 5 V/DIV (Y): 2 ms/DIV (X), DC range
Measurement condition: Idling after warm-up (no load)

APV motor control (-)

Fig 6: View Of APV Motor Control (-) Wave Pattern

G05981107

Courtesy of MAZDA MOTORS CORP.

Terminal connected: 2F (+)-Negative battery terminal
Oscilloscope setting: 5 V/DIV (Y): 20 ms/DIV (X), DC range
Measurement condition: High engine speed after warm-up

Eccentric shaft position sensor

Fig 7: Eccentric Shaft Position Sensor Wave Pattern

G05981110

Courtesy of MAZDA MOTORS CORP.

Terminal connected: 2AG (+)-Negative battery terminal
Oscilloscope setting: 2 V/DIV (Y): 5 ms/DIV (X), DC range
Measurement condition: Idling after warm-up (no load)

Field coil control (Generator)

Fig 8: View Of Field Coil Control (Generator) Wave Pattern

G05981111

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Terminal connected: 2AI (+)-Negative battery terminal
Oscilloscope setting: 0.5 V/DIV (Y): 1 ms/DIV (X), DC range
Measurement condition: Idling after warm-up (no load)

Generator output voltage

Fig 9: View Of Generator Output Voltage Wave Pattern

G05981112

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Terminal connected: 2AJ (+)-Negative battery terminal
Oscilloscope setting: 2 V/DIV (Y): 2 ms/DIV (X), DC range
Measurement condition: Idling after warm-up (no load)

Ignition coil (L/F, L/R, T/F, T/R)

Fig 10: Ignition Coil (L/F, L/R, T/F, T/R) Wave Pattern

G05981113

Courtesy of MAZDA MOTORS CORP.

Terminal connected:

L/F: 2AX (+) -Negative battery terminal

L/R: 2AT (+) -Negative battery terminal

T/F: 2BA (+) -Negative battery terminal

T/R: 2AW (+) -Negative battery terminal

Oscilloscope setting: 2 V/DIV (Y): 10 ms/DIV (X), DC range
Measurement condition: Idling after warm-up (no load)

Fuel injector (FS, RS) control

Fig 11: Fuel Injector (FS, RS) Control Wave Pattern

G05981114

Courtesy of MAZDA MOTORS CORP.

Terminal connected:

FS: 2BC (+)-Negative battery terminal

RS: 2AZ (+)-Negative battery terminal

Oscilloscope setting: 5 V/DIV (Y): 5 ms/DIV (X), DC range
Measurement condition: Racing after warm-up (no load)

Fuel injector (FP, RP) control

Fig 12: View Of Fuel Injector (FP, RP) Control Wave Pattern

G05981115

Courtesy of MAZDA MOTORS CORP.

Terminal connected:

FP: 2BB (+)-Negative battery terminal

RP: 2BD (+)-Negative battery terminal

Oscilloscope setting: 5 V/DIV (Y): 10 ms/DIV (X), DC range
Measurement condition: Idling after warm-up (no load)
Terminal connected:

FP: 2BB (+)-Negative battery terminal

RP: 2BD (+)-Negative battery terminal

Oscilloscope setting: 5 V/DIV (Y): 10 ms/DIV (X), DC range
Measurement condition: Cranking while the engine is cold. (ECT: Approx. 20 °C {68 °F})

Fig 13: View Of Fuel Injector (FP, RP) Control Wave Pattern

G05981116

Courtesy of MAZDA MOTORS CORP.

HO2S heater control

Fig 14: View Of HO2S Heater Control Wave Pattern

G05981117

Courtesy of MAZDA MOTORS CORP.

Terminal connected: 2BE (+)-Negative battery terminal
Oscilloscope setting: 5 V/DIV (Y): 100 ms/DIV (X), DC range
Measurement condition: Idling after warm-up (no load)

A/F sensor heater control

Fig 15: A/F Sensor Heater Control Wave Pattern

G05981118

Courtesy of MAZDA MOTORS CORP.

Terminal connected: 2BG (+)-Negative battery terminal
Oscilloscope setting: 5 V/DIV (Y): 50 ms/DIV (X), DC range
Measurement condition: Idling after warm-up (no load)