2003 Nissan Altima S - Camshaft & Crankshaft Position Sensors
2003 Nissan Altima S 2.5L W/Automatic Transmission
INTERMITTENT NO-STARTS & ROUGH-STARTS WITH NO DTCs SET.
A LOCAL AUTOSHOP HAD REPLACED ONLY THE CAMSHAFT POSITION SENSOR, MADE SURE
NO DTCs PRESENT AND OPS CHECK GOOD.
HOWEVER, THE PROBLEM RETURNED.
NOW, THE SAME AUTOSHOP BELIEVES THAT THE FAULT IS WITH THE TRANSMISSION
FLEX PLATE, WHICH MAY HAVE DAMAGED THE CRANKSHAFT POSITION SENSOR AS WELL,
ACCORDING TO HIM.
ESTIMATE IS AT ~$750.
The mechanic didn't try to replace the Crankshaft sensor alone, he went
straight for the Tranny drop. I figured go with the cheap fix first. If it
comes back, then we will look into the Flex Plate.
I replaced the recently replaced Camshaft sensor & the never been replaced
Crankshaft sensor. So far, so good.
Replacing the Camshaft sensor is a 2-minute job.
The Crankshaft sensor will likely take 30 times as long.
It seems like the Old Crankshaft Position sensor I removed was a bit high
on a resistance check, when compared to brand new sensors. With too high a
resistance value, the sensor may not make use of the full voltage it is
receiving and/or it may not return the required amount of voltage to the
Powertrain Control Module (PCM), which will lead to irregular engine
operation or a no-start condition.
Both Camshaft & Crankshaft sensors are the same part number. The 3rd
version of the sensor is encased in metal, not plastic.
The OEM part number is 23731-6N21A ($44 us)
The old part numbers were encased in plastic. These part numbers should not
be used: 23731-8J005 & 23731-8J006
FOR ONLINE PART PURCHASE:
"DIGITALDXING" PROVIDED THE LINKS LISTED BELOW AND POSTED SOME PICTURES
(2003 NISSAN ALTIMA 2.5L)
"PAUL" POSTED HIS PICUTRES HERE (2002 NISSAN ALTIMA 2.5L)
"DENTNSHELL" POSTED HIS FIX HERE (2005 NISSAN ALTIMA 2.5L)
"MULEMAN" POSTED A GREAT STEP-BY-STEP WRITE UP WITH PICTURES HERE (2006
NISSAN ALTIMA 2.5L)
Thanks a bunch, muleman.
...ACTUALLY, THAT WHOLE THREAD AT NISSANCLUB.COM IS A GOOD READ.
Best Answer - Chosen by Voters
Nissan recalls that problem to reprogram the ECU. What happens the crank
sensor electrical terminals seep oil into the crank sensors plug. The new
metal crank sensors correct this problem. Location of this sensor on the
back of the motor is difficult to change and you need gorrilia finger grip
to depress the connector green lock and remove the sensor. Depending on
your cars Vin# Recall Campaign # R0712 NHTSA# 07V-527. Hopefully your
factory warranty replaces the sensor no charge 5yr/60,000 mile. The
campaign only covers the ECM reprogram. The ECM reprogram makes both
sensors act as one so either will allow the car to start. Stalling and not
starting is a safety risk.
Nissan Master Technician (John Paul)
For some information on related DTC faults:
03' ALTIMA 2.5S, engine shot due to Pre-Cat b
3/10/09 rebuild finished check it out at
My 03 Altima 2.5 e
How to diag 02-06 Nissan SES light
**NOTE** This process can be tedious and nerve racking because it may not
work up to 20 times or more, if you're not familiar with the timing.
Nissan's time windows for each step are very narrow, so if you're not
getting it at first, perhaps you need to do it faster or slower and you'll eventually do it
This video is a tutorial on how to diagnose why your 02-06 Nissan is
displaying the SES (service engine soon) light by using your cars built in
OBD (on board diagnostic) system. I have a 2003 Nissan Altima 2.5S. It has
been confirmed to also work on an 06 Sentra SpecV, 09 Infiniti G37, 08
Patrol 4800 VTC, 03 Sentra GXE 1.8L, 11 Cube, 06 G35, as well as a 350z.
Check out the thread over at nissanclub.com:
Review: 2005 Nissan Altima SE-R
Go to MYRIDE.COM for more car videos.
Traditionally, Nissan's SE-R nomenclature has been reserved for various
hot-rodded Sentra models dating back to 1991. Starting this September,
speed junkies will be able to purchase a version of the 2005 Nissan Altima
that wears the SE-R badge, offering slight bumps in engine horsepower and torque and
providing yet another reason to skip paying extra for the larger, heavier
Maxima flagship sedan
2005 Nissan Altima Full In Depth Tour, Start Up, and Driving
Yet another full detail that I have done, this time it's to a 2005 Nissan
altima 2.5 S, pretty nice car and drives really nice too. In this video I
do a full tour, engine shot, start up, and take a short drive, hope
everyone enjoys! I'm trying to do a new style on how I make these videos.
For anyone reading this description, subscribe today, you don't want to
miss what I have this weekend, it will be epic ;)
2002 Nissan Altima 2.5S Misfire start
This Nissan Altima was sold (used) to me with this problem hidden, and a
few weeks later, it began to get noticeable, and it continued to get worse.
I ended up losing around $7,000 total. I had this car checked by a master
mechanic who works at a local dealership and does excellent work, and noone
had thought this car would give any trouble. After several weeks, we
noticed it eating approximately 1qt / wk of oil, and as well having issues
starting and misfiring (all caused by the same thing). To those of you
thinking of purchasing a Nissan, my advice is don't, and especially not
from Armo Motors. They sold this engine (First gen QR25DE) for 4 years, in
the 2002 - 2006 Nissan Altima 2.5S, the 2002 - 2006 Sentra SE-R, and the
2005 Frontier, and ALL THREE have issues. Nissan has had a few recalls on
them, but still refuses to admit that all those cars had issues. They claim
that although the engine is the same, and shows the same issues, that it is
only truly their fault in a few cases. My particular car had two major
issues that Nissan shoved under the carpet. The first is that the mesh that
holds the catalytic converter material in place can come off, and cat
material can clog the Exhaust, or
worse, get pushed into the engine. The second is that the screws that hold
the butterfly valves in place can come loose and literally get sucked into
the engine. Both of these will cause increased oil consumption, and
(evenually) can lead to a dead engine. After contacting the dealer at Armo
I asked if he could possible help with part of rebuilding the engine, and
he said he had a shop that could do it, and he would pay half. We were
about to get it rebuilt, and when we went to ask for his half, he said
'I've talked to my lawyer, and he says it's best that I don't help you
because it would imply that there was a warranty on the car, which would
give you further grounds to sue' and hung up. I bought a Honda Civic since
then and took the hit; Still waiting from that settlement from Nissan
http://www.youtube.com/watch?v=5r_9qcSQBfc is a continuation of problems I
2004 sentra idle relearn won't work
Did the process multiple times and didn't work.
On 2 sec
Off 10 sec
On 2 sec
Off 10 sec
Ignition on then off to make sure valve is closed.
Start car let it warm.
Turn off 10 sec.
Turn key to on for 3 sec
Press pedal 5 times in less than 5 sec.
Wait 7 sec then press in pedal and hold
When light starts flashing then goes solid let go within 3 sec
Start car after.
Any ideas why not working?
2003 Altima 2.5S Precat Removal Header Install
Here I show you the dreadful Nissan header/precat and a suitable
replacement header. If you own a 2.5L Altima, Sentra, etc you must make
this fix. This part fails at a very high rate and the end result is always
catastrophic engine failure. To check out the model I bought and seller go
For more info check out
http://www.b15sentra.net/forums/showthread.php?t=135241. I would also
advise that you complete the intake screw fix mentioned on the above
mentioned link. The altima is a beautiful car for a great price, but if you
purchase the 2.5L model be prepared to fix these probems and make sure all
recalls have been completed. My car had 4 recalls including a subframe
replacement. Nissan really had their head up their ass on this one. Cheers.
2003 Nissan Altima Transmission Flare-Up
Please see note on bottom. This is an example of a Nissan 4speed Automatic
You'll notice the engine revs up an extra ~700RPM during the shift between
2nd and 3rd gears. This creates excess transmission heat and is the result
of a worn-out / loose band between 2nd and 3rd gear. There is an external
fix that involves tightening the band, but I do not know how it is
Unfortunately this is a typical problem for these transmissions. I (thank
God!) had an extended warranty on the car that covered the costs of a new
NEW NOTE: Mike James from Nissan Club posted a video with a mask-fix for
this kind of flare. You can watch it here:
NOTE: This problem occurred months before I took the vehicle to the track.
Therefore - racing is unrelated to it's failure.