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: