HO2S Voltage Inspection
Note
1. Warm up the engine and run it at idle.
2. Disconnect the HO2S connector.
3. Connect the voltmeter test leads to the following HO2S terminals:
- (+) leadterminal A
- (-) leadterminal B

4. With the vehicle stopped, run the engine at 3,000 rpm
until the voltmeter moves between 0.5 and 0.7 V.
5. Verify that the measurement voltage changes when the engine speed increases and decreases suddenly several times.
Specification

Circuit Open/Short Inspection (Sensor)
1. Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION.)

2. Inspect the following wiring harnesses for open or short. (Continuity check)
Open circuit
Front
- HO2S terminal A (harness-side) and PCM terminal 1AB (harness-side)
- HO2S terminal B (harness-side) and PCM terminal 2H (harness-side)
Rear
- HO2S terminal A (harness-side) and PCM terminal 1Y (harness-side)
- HO2S terminal B (harness-side) and PCM terminal 2H (harness-side)
Short circuit
Front and Rear
- HO2S terminal A (harness-side) and body GND
- HO2S terminal A (harness-side) and power supply
- HO2S terminal B (harness-side) and power supply
HO2S Heater Resistance Inspection
1. Disconnect the HO2S connector.
2. Measure the resistance between the HO2S terminals C and D.
Specification
Front : 3.0-3.6 ohms
Rear : 5-7 ohms

Circuit Open/Short Inspection (Heater)
1. Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION.)

2. Inspect the following wiring harnesses for open or short. (Continuity check)
Open circuit
Front
- HO2S terminal C (harness-side) and ignition switch
- HO2S terminal D (harness-side) and PCM terminal 4A (harness-side)
Rear
- HO2S terminal C (harness-side) and ignition switch
- HO2S terminal D (harness-side) and PCM terminal 4D (harness-side)
Short circuit
Front and rear
- HO2S terminal C (harness-side) and body GND
- HO2S terminal D (harness-side) and power supply
- HO2S terminal D (harness-side) and body GND
Knock sensor removal/installation
Power steering pressure (psp) switchinspectionMazda 6 Service Manual: Settings
NOTE
Depending on the grade and specification, the screen display may differ.
Select the icon on the home
screen and display the Settings screen.
Switch the tab and select the setting item you want to change.
You can customize settings in the setup display as follows:
...
Mazda 6 Service Manual: Variable tumble control system (vtcs) shutter valve actuator inspection
1. Remove the air hose. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION.)
2. Disconnect the vacuum hose from the VTCS shutter valve actuator.
3. Connect a vacuum pump to the VTCS shutter valve actuator.
4. Apply vacuum and verify that the rod moves.
If the rod dose not move, replace the intake ...