hcarter1112

I am new to the forum and a new and proud owner of a 2001 Nissan Maxima 20th Anniversary Edition (M/T). The car came with all of the bells and whistles, including several DTC's... Those should be easy and are not really my reason for appealing to this awesome maxima resource. I have a very odd problem... the speedo is inaccurate with no current trouble codes...

ok so i am driving the car home and swooning over my new found power and speed when i notice that i am apparently going 25-40 mph... when i knew i was going MUCH faster than that (about 60-75 mph). The really really confusing part is that the ECM is not throwing a DTC for this... no p0702 or p0500 or anything. I am going to do some further diagnostic testing with my scan tool and see if the VSS output and the speedo agree... If they do then i know the problem is at the VSS... If not then i know it is the speedo...

I have heard about the infamous little plastic gear on the VSS that has a tendency to loose teeth... might this be a cause? has anyone ever experienced this? I have an all data subscription and cannot find the speedo circuit anywhere... so i don't really know how the speedo gets its readings. Any help with this would be very much appreciated!

george__

iTrader: (1)

It could be the old owner didn't install the right tire size

hcarter1112

the tires are the stock alloys

george__

iTrader: (1)

Tire size is not the same as rim size...

http://www.tirerack.com/tires/tirete....jsp?techid=36

With that big of a speed difference though your gauge cluster could be stuck or broken

TallTom

Different tire sizes than OEM would not throw it off 30mph. Maybe 5mph tops.

hcarter1112

the wheels and tires are the right sizes. i am leaning toward it being the cluster but is there anyway to be sure that it is the cluster? Nothing else seems to be affected but the speedo.

DennisMik

iTrader: (2)

The signal to the speedometer comes from the transmission. There is a revolution sensor in the transmission that could be messed up.

But the odds are that it is the speedometer itself that is messed up. Run the self diagnostic on the instrument cluster. See page 117 in the link below.

http://boredmder.com/FSMs/Nissan/Maxima/2001/EL.pdf

hcarter1112

ok so... further testing...

1) i tested the gauges and they function properly... Thanks for the link btw... that method worked like a charm

2) i hooked up a scan tool and monitored the speed with the car up on the lift... The gauge is working correctly... i was registering inaccurate speed readings on the scan tool and on the speedo but they matched eachother... so... it is definately a sensor on the trans... which one??? Is it the VSS or the rotation sensor? i really wish i had a schematic for this circuit...

george__

iTrader: (1)

^
Look at the FSM

http://boredmder.com/FSMs/Nissan/Maxima/2001

DennisMik

iTrader: (2)

Neither. Both the VSS and the revolution sensor are for the automatic transmission.

The part for the manual transmission is called the speedometer pinion.

There are 3 part numbers listed for the 2001 - 32702-31U00, 32702-3Y112 and 32702-5V000. Because of the different part numbers being for different options, I would suggest you talk to the dealer and have your VIN with you.

They look like this:

hcarter1112

ok... well i am hearing 3 conflicting ideas... the car is registering half of the speed i am travelling... so i am going 70 and the speedo reads 35... 50 speedo reads 25...

I have scoured the internet for hours with tons of conflicting ideas...

1) unless you have TC you dont have a pinion sensor

2) if you dont have TC then your car gets its speed readings from your abs wheel sensors (i am not sure which 1 of the 4 might be bad and have no clue how to test for it

3) that your car could have both that work together...

I am so confused... I am not trying to throw 150 dollars at this just for it not to fix anything... i have NO SES light for the VSS or Pinion sensor and no abs light...

do i get my reading for my speedo from the pinion sensor or the wheel speed sensors in the abs system?

wouldnt my car throw a trouble code if it was the pinion? like a p0500 or something?

hcarter1112

ok so update... looked under the car at the ABS wheel speed sensor just to make sure it wasnt something obvious... well it was... the wire for the ABS wheel speed sensor was cut... so i spliced the wires together and tada!!! Speedo is accurate! I will be getting a replacement sensor and we are good! thanks for your help everyone!