Nissan Altima

Tiny
TXCANTU
  • MEMBER
  • 2004 NISSAN ALTIMA
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 120,000 MILES
I have a nissan altima 2004 4cyl I was driving it and the service light came on I took to autozone and they gave me the codes that popout P0335, P0420, AND P0725 what could it be
Sunday, February 20th, 2011 AT 12:29 AM

1 Reply

Tiny
KHLOW2008
  • MECHANIC
  • 41,815 POSTS
DTC P0335: CKP SENSOR (POS)
COMPONENT DESCRIPTION
The crankshaft position sensor (POS) is located on the cylinder block rear housing facing the gear teeth (cogs) of the signal plate at the end of the crankshaft. It detects the fluctuation of the engine
revolution.

The sensor consists of a permanent magnet and Hall IC.

When the engine is running, the high and low parts of the teeth cause the gap with the sensor to change.

The changing gap causes the magnetic field near the sensor to change.

Due to the changing magnetic field, the voltage from the sensor changes.

The ECM receives the voltage signal and detects the fluctuation of the engine revolution.

DTC P0420: THREE WAY CATALYST FUNCTION
ON BOARD DIAGNOSIS LOGIC
The ECM monitors the switching frequency ratio of air fuel ratio (A/F) sensor 1 and heated oxygen sensor 2.

A three way catalyst (manifold) with high oxygen storage capacity will indicate a low switching frequency of heated oxygen sensor 2.

As oxygen storage capacity decreases, the heated oxygen sensor 2 switching frequency will increase.

When the frequency ratio of air fuel ratio (A/F) sensor 1 and heated oxygen sensor 2 approaches a specified limit value, the three way catalyst (manifold) malfunction is diagnosed.

DTC P0725 ENGINE SPEED SIGNAL
DESCRIPTION
The engine speed signal is sent from the ECM to the TCM.

ON BOARD DIAGNOSIS LOGIC
Diagnostic trouble code ENGINE SPEED SIG with CONSULT-II or P0725 without CONSULT-II is detected when TCM does not receive the proper voltage signal from ECM.

POSSIBLE CAUSE
Check harness or connectors. (The sensor circuit is open or shorted.)
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Monday, February 28th, 2011 AT 2:42 PM

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