Greetings, I just bought a 96 I30, CEL was on and showed codes PO325 (Knock Sensor) & P1336 (Crank Sensor) in addition the tach was pegged and not moving at all. Cleared the codes and the tach starting working again, after running it for a bit the tach starting jumping around, no rhyme or reason, just jumping around. CEL not on now, Wondering if the crank sensor going bad would cause the tach to start jumping ? Car runs and idles smooth.

 

There are 2 crankshaft sensors on the engine. CKPS(POS) senses the teeth on the flywheel and is very important to ignition timing. CKPS(REF) senses TDC on the harmonic balancer.

CKPS(POS) creates a pulse for every 1 degree of crankshaft revolution. P0336 is the code for this sensor.

CKPS(REF) creates 1 pulse for every full revolution of the crankshaft. It is in sync with TDC on cylinder # one. P1336 is the code for this sensor.

If the flywheel sensor goes bad, the engine won't run. If the harmonic balancer sensor goes bad, the engine will crank a while before it starts.

Before replacing these sensors, remove them and clean them, especially the tip.

The tach works off of the flywheel crankshaft sensor, so it is not related to the P1336 code.

The knock sensor code may not be a valid problem. That code is referred to as a ghost code as it likes to pop up whenever you have any other code. Take care of the other problems and 95% of the time, the P0325 will go away. FYI - the P0325 by itself will not cause the check engine light to come on.

edit -

Click on this link below and scroll down to post # 4 by CS_AR. The 2nd photo shows the CKPS(REF) sensor, your P1336 code. In the photo, the oil filter and the harmonic balancer are not installed.

https://maxima.org/forums/4th-genera...tor-light.html

edit 2 - corrected statement about tachometer