Fuel injection control (-) signal

Fig 1: Fuel Injection Control (-) Wave Pattern Signal

Courtesy of MAZDA MOTORS CORP.

PCM terminals 

• Fuel Injection No. 1: 1DH (+) -body ground (-)
• Fuel Injection No. 2: 1CZ (+) -body ground (-)
• Fuel Injection No. 3: 1CV (+) -body ground (-)
• Fuel Injection No. 4: 1DD (+) -body ground (-)

Oscilloscope setting 

• 10 V/DIV (Y), 5 ms/DIV (X), DC range

Vehicle condition 

• Idle after warm up