ECU code: knock sensor & Air intake temperature sensor

[boopathyk]

Hi,

I am having 1997 Model Nissan Maxima GLE. Recently I did an oil change and after that my 'Service Engine Soon' light starts glowing. I consulted with Scott(maxhopper97) and he directed me to identify the error code. Thanks for him. (mail thread is given below for reference). I followed the procedure mentioned by Scott and identified the error codes as 0304(Knock Sensor) and 0401(Air Intake Temp Sensor).

I read from internet that knock sensor hears for engine knock and send signals to ECU, if it finds any. I do have following queries,1. Does the 0304 implies to change the knock sensor? or2. Does 0304 specifies some problem within engine? In this case do we really need to change the knock sensor

Recently I replaced the starter of my car. After that, whenever I starts my car, I heard a raising noise. Do this inturn results in the error code of 0304?

I am awaiting for your replies. Please get back.

***************************************************************Mail thread from scott:from Scott Keller <[email protected]>reply-to [email protected] boopathy krishnamoorthy <[email protected]>date Tue, Jul 15, 2008 at 2:07 PMsubject Re: favourmailed-by yahoo.comsigned-by yahoo.com hide details 2:07 PM (7 hours ago) Reply

Hi,



There is nothing with an oil change that should have caused the check engine light to come on; I'm sure it's something unrelated.



Check here to find out how to retrieve your codes for the check engine light.

http://vbxmaxima.8m.com/ecu.html



Then look here to find out what the code means.

zerothread?id=126542



If you have any other questions just let me know, or post a thread on NICO.



Regerds,

Scott

maxhopper97

--- On Sun, 7/13/08, boopathy krishnamoorthy <[email protected]> wrote:

From: boopathy krishnamoorthy <[email protected]> Subject: favour To: [email protected] Date: Sunday, July 13, 2008, 10:44 PM - Hide quoted text -

Hi,

Can you please do me a favour? Just now I had left my car (Nissan Maxima 1997 GLE) for an engine oil change. After the engine oil change, I have noticed the Service Engine Soon(SES) light glowing. I am very much sure that it had happened ONLY after the Oil change. I checked with the person who had done the oil change and he said that the oil change is no where related with the SES light and he asked us to leave the car for the thorough check of the engine.

I am very much wondering how that 2 hours(oil change) had done this effect. And I am worried about the spending too much on this. My car had covered around 115000 miles. Can you please help me in diagnosing this problem? Or can you please share your knowledge of what could be the problem?

Do the Oil change will create any such problem?

Please clarify me.

Thanks, Boopathy.

[allensteiner]

here's my thought: i used to work as a grease monkey and after every oil change the tech starts the car to make sure there is oil pressure - the oil light goes off. maybe someone unaware of oil being drained started the car?

other things - reset the ecu by disconnecting the battery for 30mins. that'll make the light go off and just wait to see if it comes back.

[boopathyk]

The person, who had done the oil change, have resetted the ECU. But the 'Service Engine Soon' light comes once again after some 1 hour.

1. Does the 0304 implies to change the knock sensor? or2. Does 0304 specifies some problem within engine? In this case do we really need to change the knock sensor

Also I am thinking whether this is due to my recent starter change. Recently I replaced the starter of my car. After that, whenever I starts my car, I heard a raising noise. Do this inturn results in the error code of 0304?

[NutriaforBreakfast]

You check to see if your sensors are working correctly byusing a multimeter. See if you are getting 12V to the sensorsfrom the battery and check the resistance of the sensors too.

Maybe you also got some subpar fuel which would cause thesensor to activate. From other cars, my experience with knocking(predetination)comes from engines operated at high speeds. I havent felt a lowspeed engine knock before. I am sure there are some trucks outthere that are pulling heavy loads and have engine knock as theytry to start pulling the load from a red light or other stop due to lowoctane or bad gas. Try putting some octane boost in the tank and seehow it runs for a couple of days.

Maybe your timing if off and the fuel is ok but the car thinksthe fuel is bad.