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Code 21

DTC 21 - Main Oxygen Sensor Circuit

Purpose of the driving pattern:
* To simulate diagnosis code detecting condition after diagnosis code is recorded.
* To check that the malfunction is corrected when the repair is completed confirming that the diagnosis code is no longer detected.


DTC 21 - Main Oxygen Sensor Circuit:





1. Disconnect the fuse EFI (15 A) for 10 seconds or more, with IG switch OFF.
2. Start the engine and warm the engine up with all ACC switch OFF.
3. After the engine is warmed up, let it idle for 3 minutes.
4. Accelerate gradually and maintain at approximately 1,500 rpm, or within the 1,300 to 1,700 rpm range. Turn the A/C on, and drive in "D" for A/T, or in case of M/T, upshift appropriately shift carefully so that the engine speed would not fall below 1,200 rpm., depress the accelerator pedal gradually and maintain a steady speed to avoid engine braking.
5. Maintain the vehicle speed at 40 - 50 mph.
Keep the vehicle running for 1 - 2 minutes after starting acceleration.
6. After driving, stop at a safe place and turn the IG switch OFF for 3 seconds. or more.
7. Start the engine and perform steps 3, 4, and 5 again.

HINT: If a malfunction is detected, the Malfunction Indicator Lamp will light up during step 7.

NOTICE: If this procedure is not strictly followed, you can not detect the malfunctions.