Air Fuel Ratio Compensation System (Es300)
Measure voltage (backprobe) between ECM connector terminals. See Fig 1. For voltage specifications, see AIR FUEL RATIO COMPENSATION SYSTEM VOLTAGE SPECIFICATIONS table. Connect hand-held tester to DLC3. Select DATA MONITOR A/FS B1 S1. A/FS B2 S1 and O2S B1 S2 should display on monitor. Warm up A/F sensor with engine speed at 2500 PRM for about 2 minutes. Keep engine speed at 2500 RPM and confirm displays of A/FS B1 S1 and A/FS B2 S1 are as shown in illustration. Confirm display of O2S B1 S2 changes between 0-1 volt with engine speed at 2500 RPM. See Fig 2.
NOTE:
Illustration is different from real display. Only hand-held tester displays waveform of A/F sensor.
AIR FUEL RATIO COMPENSATION SYSTEM VOLTAGE SPECIFICATIONS
| Terminal | Condition | Voltage |
|---|---|---|
| AFR+ - E1 | Ignition Switch On | 3.3 |
| AFR- - E1 | Ignition Switch On | 3.0 |
| AFL+ - E1 | Ignition Switch On | 3.3 |
| AFL- - E1 | Ignition Switch On | 3.0 |