Hot to Check MAF--Write up
#1
Hot to Check MAF--Write up
This is a "How to" write up with links to pictures. (Sorry I don't know how to upload them, if this becomes a link in the FAQ sticky, I will edit and try to get moderator help) SO here it goes:
Your MAF is located on your air box between your Throttle body and Air filter. It sets about 8-12 inches back from the air filter itself. It has 2 Torx screws holding it down.
The 4 wires are color coated as follows (2000 model) from right to left. (From passenger side to driver side) (Left to right in the pictures)
White wire: Signal wire - This will change as your speed/load changes - This is the wire the ECU/TCM takes information from to alter shifts, A/F ratio, timing,etc.
Red wire : Reference wire - This should stay the same. This wire is from a hot source and has some sort of resistor to send only 5 V to the wire.
Black wire: Ground wire - Should be .05 or less VD from battery ground.
Red wire w/ Green strip: power wire - Should be battery voltage.
Thanks to puppetMaster for the MAF signal specs they are as follows.
All readings are at Engine operating temp, and no load. ( radio, head lights, ac, heat off)
SIGNAL WIRE (white wire)
Idle: 1.1V-1.5V --alldata says 1.2 - 1.8 volt
2500 RPM: 1.7V - 2.4V
Reference Wire (Red wire): should be @ or just below 5 V. If this is low your Maf signal wire will send low #'s to the ECU.
GROUND WIRE (black wire) .05V or less - SHould not change more than .02 volts with load or engine speed increase.
POWER WIRE (red with green strip) Battery voltage. (13 - 15V) Should be close to the voltage you get when checking battery terminal to terminal. Alldata says 11-14.- IMO- If you have 11V your battery is either dead or you have an electrical problem..... again-IMO.
I couldn't find any specs for the ground or reference so these are universal specs among all domestic/import MAF sensors.
For some pictures here is a link.
http://www.cardomain.com/ride/2195944/2
Your MAF is located on your air box between your Throttle body and Air filter. It sets about 8-12 inches back from the air filter itself. It has 2 Torx screws holding it down.
The 4 wires are color coated as follows (2000 model) from right to left. (From passenger side to driver side) (Left to right in the pictures)
White wire: Signal wire - This will change as your speed/load changes - This is the wire the ECU/TCM takes information from to alter shifts, A/F ratio, timing,etc.
Red wire : Reference wire - This should stay the same. This wire is from a hot source and has some sort of resistor to send only 5 V to the wire.
Black wire: Ground wire - Should be .05 or less VD from battery ground.
Red wire w/ Green strip: power wire - Should be battery voltage.
Thanks to puppetMaster for the MAF signal specs they are as follows.
All readings are at Engine operating temp, and no load. ( radio, head lights, ac, heat off)
SIGNAL WIRE (white wire)
Idle: 1.1V-1.5V --alldata says 1.2 - 1.8 volt
2500 RPM: 1.7V - 2.4V
Reference Wire (Red wire): should be @ or just below 5 V. If this is low your Maf signal wire will send low #'s to the ECU.
GROUND WIRE (black wire) .05V or less - SHould not change more than .02 volts with load or engine speed increase.
POWER WIRE (red with green strip) Battery voltage. (13 - 15V) Should be close to the voltage you get when checking battery terminal to terminal. Alldata says 11-14.- IMO- If you have 11V your battery is either dead or you have an electrical problem..... again-IMO.
I couldn't find any specs for the ground or reference so these are universal specs among all domestic/import MAF sensors.
For some pictures here is a link.
http://www.cardomain.com/ride/2195944/2
#4
Originally Posted by 002_SecretEgent
Great stuff...can you edit the title to say "How" instead of "Hot". It will be complete then
#6
Originally Posted by ressling
awesome info but..
#7
the highest volts i get on my volt meter is 14.3 (very rare, car moveing and no electrical load) and with my systems cranking and the heats blasting, it flashes 11.8(while car is stopped), i dont believe it should ever hit 15 volts, but AWSOME write up, does this apply for the 02/03 maximas as well?
#9
Originally Posted by 5thgenmaxima
Thanks to puppetMaster for the MAF signal specs they are as follows.
Originally Posted by 5thgenmaxima
All readings are at Engine operating temp, and no load. ( radio, head lights, ac, heat off)
SIGNAL WIRE (white wire)
Idle: 1.1V-1.5V --alldata says 1.2 - 1.8 volt
2500 RPM: 1.7V - 2.4V
SIGNAL WIRE (white wire)
Idle: 1.1V-1.5V --alldata says 1.2 - 1.8 volt
2500 RPM: 1.7V - 2.4V
Originally Posted by 5thgenmaxima
Reference Wire (Red wire): should be @ or just below 5 V.
Originally Posted by 5thgenmaxima
GROUND WIRE (black wire) .05V or less - SHould not change more than .02 volts with load or engine speed increase.
Originally Posted by 5thgenmaxima
POWER WIRE (red with green strip) Battery voltage.
Originally Posted by 5thgenmaxima
Even though everything checked out good. I am still suspecting a problem, so I'm going to put a scope on it and put it under a load. (I am in the middle of specs @ both idle and 2500 RPM, But went to WOT till it hit rev limiter and the highest read-out was 4.13- Not even close to 4.96 I got from my reference wire)
#10
I went and looked up the 2000 FSM and got the same numbers you did initially:
Ignition "ON", engine off: 1.0V
Idle (engine fully warmed up): 1.2-1.8V
2,500 rpms: 1.6-2.2V
4,000 rpms: approx 4V with linear increase in rpms from idle
Everything else is the same. Sorry for the oversight, but at least now we have the 2002-03 numbers (in my previous post) as well.
Ignition "ON", engine off: 1.0V
Idle (engine fully warmed up): 1.2-1.8V
2,500 rpms: 1.6-2.2V
4,000 rpms: approx 4V with linear increase in rpms from idle
Everything else is the same. Sorry for the oversight, but at least now we have the 2002-03 numbers (in my previous post) as well.
#12
What I mentioned in the first sentence.Simply take a multimeter. Put the black lead battery ground (-) and backprobe the red wire into each wire on the MAF...I'm not for certain that this will defiently pick maf problems...I still think I have maf probelms even though mine checked out ok. I'm guessing there may be "dead spots" , under a load it may give different readings, or the problem might be intermittent (occassional). So I'm going to put it uder a load while I have it on a scope. (This is something you will not be able to do, good quality scopes can cost upwards of $3500 +.) As for the multimeter. Go to harborfreight buy one for $2.99 and that comes with the leads.
Puppet you seem to know what your talking about....Does this test usually pick up weak maf sensors? - Do most of the nissans MAF problems only occur under a load???? Do most people you have to replace their MAF have transmission shift problems?? --Just wondering for my own info. Thanks in advance.
Puppet you seem to know what your talking about....Does this test usually pick up weak maf sensors? - Do most of the nissans MAF problems only occur under a load???? Do most people you have to replace their MAF have transmission shift problems?? --Just wondering for my own info. Thanks in advance.
#13
Originally Posted by 5thgenmaxima
Does this test usually pick up weak maf sensors? - Do most of the nissans MAF problems only occur under a load???? Do most people you have to replace their MAF have transmission shift problems?? --Just wondering for my own info. Thanks in advance.
#14
This is very interesting. Keep up the good work. When i get some time i'm going to look into this myself. Also to note, the 5.5th gen maximas for the year 2002 have 2 different mafs. I found this out through Dave B awhile back. Apparently they had a weaker maf and a stronger maf. SOme 2k2 came with the weaker mafs but luckly i crossed checked the part number on my maf with him and he said i had the newer one. I know the maf has never been replaced at the dealer. Thought i'd toss this little bit of tid bit in here. What's up puppetmaster. havent talked to ya in awhile.
#15
Originally Posted by bugbite77
the highest volts i get on my volt meter is 14.3 (very rare, car moveing and no electrical load) and with my systems cranking and the heats blasting, it flashes 11.8(while car is stopped), i dont believe it should ever hit 15 volts, but AWSOME write up, does this apply for the 02/03 maximas as well?
#20
I'm going to go outside and test this tomorrow. I cannot go past 2500RPM. It bounces off of it like a rev limiter. If I get a reading outside of the 1.7-2.4V, is that a fault of the MAF or the ECM? If it's the signal wire, I assume that's the signal going BACK TO the ECU, so it would be the MAF at fault, so long as my 12V and 5V lines are stable. Correct?
DISREGARD: Found out that code P0650 combined with any other CEL code will cause 2500RPM fuel cutoff.
DISREGARD: Found out that code P0650 combined with any other CEL code will cause 2500RPM fuel cutoff.
Last edited by mydecember1985; 06-26-2022 at 02:21 PM.
Thread
Thread Starter
Forum
Replies
Last Post
Jer
5th Generation Maxima (2000-2003)
5
03-23-2003 01:06 AM
poorcollegeboy
3rd Generation Maxima (1989-1994)
5
07-13-2002 07:36 PM