Smoke_Screen

Im sure there are several people out there who can answer this, but I tried and it didn't work so I need some advice.

I currently have a 'Check Engine Soon' light which is on because of a bad O2 sensor. I want to put the new O2 sensor on, but want to reset the car's computer so that the code will be cleared when I turn it back on.

So, how do I clear the codes???

Thanks

redls1

iTrader: (2)

Go to your local autozone and they do it for free or

ECU Resetting Procedures
Timing is extremely critical. If it is NOT DONE within the specify time, the ECU will not reset and the Check Engine Light (CEL) will continue to remain ON.
A stop watch or an analog clock with a second’s needle will be useful.
Operations Procedures
1. Confirm that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.
2. Repeat the following steps (2a and 2b) procedures quickly five times within 5 seconds.
2a. fully depress the accelerator pedal (HARD).
2b. fully release the accelerator pedal.
3. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the CEL starts blinking.
4. Fully release the accelerator pedal (while the CEL is still blinking
5. Wait about 10 second.
6. Fully depress the accelerator pedal and keep it for more than 10 seconds.
7. Fully release the accelerator pedal (The CEL light will continue to blink).
8. Turn ignition switch to “OFF” position and now you can start the car. The CEL light should be gone.
If the CEL light continues to remain ON, repeat the above steps. Timing is EXTREMELY critical to resetting the ECU.

Accelerator Pedal Release Position Learning
Operation Procedure
1. Make sure that the accelerator pedal is fully released.
2. Turn ignition switch “ON” and wait at least 2 seconds.
3. Turn ignition switch “OFF” wait at least 10 seconds.
4. Turn ignition switch “ON” and wait at least 2 seconds.
5. Turn ignition switch “OFF” wait at least 10 seconds.


Throttle Valve Closed Position Learning
Operation Procedures

1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch is “ON”.
3. Turn ignition switch is “OFF” wait at least 10 seconds.
Make sure that the throttle valve moves during above 10 seconds by confirming the operating sound.

Idle Air Volume Learning (Throttle Position Learning)
It is better to count the time accurately with a clock.
Operation Procedures

1. Perform “Accelerator Pedal Released Position Learning”.
2. Perform “Throttle Valve Closed Position Learning”.
3. Start engine and warm it up to normal operating temperature.
4. Turn ignition switch “OFF” and wait at least 10 seconds.
5. Conform that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.
6. Repeat the following (steps 7a, 7b) procedures quickly five times within 5 seconds.
7a. Fully depress the accelerator pedal (HARD)
7b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the Check Engine Light (CEL) stops blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the CEL is ON.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure the idle speed and ignition timing are within the specifications

Smoke_Screen

Wow, thats kind of insane... now I know why I didnt get an answer in the other thread.

Do I need to follow the "Accelerator Pedal Release Position Learning Operation Procedure" before attempting the 8 step "ECU Resetting Procedure"?

Thanks for the info.

BadBlackMaxSL

iTrader: (1)

Does disconnecting the battery for 30 minutes or more do the same thing? I ask b/c on Friday I had my battery out for a replacement and the car was without any battery for about an hour. Thanks.

Patsky

redls1 you are my god.

redls1

iTrader: (2)

Lol just learned a little from the more knowledgeable people around here. I still have alot to learn. You can disconnect the battery also but not sure how long it takes. Give it a try.

Patsky

Not sure if the Throttle Valve Closed Position Learning really does anything, but the rest worked for me! Is that stuff in the FSM?

redls1

iTrader: (2)

Ye , page ec79. Look in the basic service procedure from the quick reference guide.

redmaxpa007

iTrader: (21)

i bet he takes donations......



pass the collection plate!

Bezzle01

The good thing about doing the reset is that it shouldnt reset the radio, sunroof and all the other electronics. I know in the 5.5 gen you have to do this, removing the ground cable doesnt reset the ecu.

This helped me alot.....

http://maxima.theowensfamily.com/ecu.asp

lostru

Thanks for he great info. Are you sure you dont have to do the hokey pokey?

ramberg

iTrader: (29)

If you already know than the O2 sensor is bad and you try to reset it, the engine light will still be on. Change the sensor than do the reset.

redls1

iTrader: (2)

I want to put the new O2 sensor on, but want to reset the car's computer so that the code will be cleared when I turn it back on.

So, how do I clear the codes???

Thanks
__________________

I think he already had the change in mind.

Bezzle01

When I changed my MAF in the 5.5 I used this reset procedure and it cleared the code. You have to do it after you change the o2 sensor.

NmexMAX

iTrader: (22)

Do the procedure AFTER you change it. Or go to your local AutoZone and have them reset it for free.

The insane method really isn't that bad, but what you must make sure of is that the car is at operating temp, because otherwise it will never work and you'll feel as if it were a sick joke.