Power is provided to the warmer power terminal of the direct A/F sensor connector from the motor control transfer connector terminal. The warmer of the direct A/F sensor connector terminal is constrained by the power semiconductor in the motor control unit /ECU/ connector terminal LHFL.[ex-toc]
The motor ECU checks whether the warmer current is inside a predefined range when the heater is on. The motor ECU checks whether the heater voltage is inside a predetermined reach when the warmer is off.
Inconvenience Judgment. Actually, look at the Conditions
Over 2 seconds have passed since the power supply method of the electric engine switch was ON. While the direct A/F sensor warmer is on. The assistant battery’s positive voltage is in excess of 11 V and is under 16.5 V.
The direct A/F sensor warmer current is under 0.17 A for 2 seconds.
Actually, look at the Conditions
Over 2 seconds have passed since the power supply method of the electric engine switch was ON. While the direct A/F sensor warmer is off. Assistant battery positive voltage is in excess of 11 V and is under 16.5 V. Flat or overcharged.
The straight A/F sensor heater voltage is under 2.0 V for 2 seconds.
Fizzled direct A/F sensor warmer.
Open/short out or saddle harm in straight A/F sensor heater circuit or free connector contact.
Failed motor ECU
Damage or broken mechanically
How to check over
Unplug the linear A/F sensor
Measure the resistance terminals 2 and 3 of the linear A/F sensor connector.
Standard value: 2.3 – 4.2 Ω (at 20°C)
If the resistance of value out of tolerance replaces the linear A/F sensor.
Check the wireline for open/short circuits.
Unplug the connector, and measure at the wire side.
Power supply mode switch: ON
The voltage between the terminal line and the body earth.
Repair or replace the connection point, check and repair the wire harness between the linear A/F sensor connection point and motor control relay connection point.
Note for intermittent fault
Softly shake the connector up, down and to the left and right.
Softly shake the wiring bridle up, down and to the left and right.
Softly rock every sensor and transfer, and so on manually.
Softly shake the wiring bridle at suspensions and other moving parts.