I'm getting these trouble codes and was wondering where to start. IT's a 95 max with 130,000 miles on it. I cleared the codes and now I'm only getting the p0325 code meaning the knock sensor. any ideas on where to start. Should take out the knock sensor or the coolant temp sensor. Or may be the thermostat? any suggestions are appreciated.

 

Hey i just got my car check by AutoZone. I got P0325 too. the dude told me is the O2 sensor. Are you sure is the knock sensor, or are they the same??

 

clear the codes.. drive it around.. see if it comes back.. if it comes back following an o2 sensor code.. then its the o2 sensor.. if it comes back with just the knock sensor.. then replace your knock sensor

http://vbxmaxima.8m.com/ecu.html

 

That code is for the knock sensor.

What Sprint said.

 

P0325 = DTC 0304 = Knock sensor or circuit fault

Diagnostic Trouble Code 0304 points to a problem with the Knock Sensor.

The KS is attached to the cylinder block. It senses engine knocking using a piezoelectric element. A knocking vibration from the cylinder block is senses as vibrational pressure. This pressure is converted into a voltage signal and sent to the Engine Control Module (The computer).

This malfunction is detected when an excessively high or low voltage from the KS is entered to the ECM.

Possible causes include...
- the harness or connector (The KS circuit is open or shorted).
- the KS


The KS may be checked with an ohmmeter.

1) Raise the hood. View the engine from the driver's fender. Look into the deep valley between the cylinder banks and below the intake manifold. Identify the KS as a black item fastened to the block by a single vertical bolt. A wire harness wrapped in black leads toward you, out of the valley. That is the KS sub-harness.

2) Follow the KS sub-harness to it's nearest connector. This is connector F121. It is located near the upper right-hand corner of the valve cover of the forward cylinder bank, as viewed from the front of the car.

3) Disconnect F121. You have to do a "press the latch and wiggle and pull" to disconnect it. F121 has only two pins; if you see more than two pins, you have the wrong connector. Use a digital ohmmeter capable of measuring more than 10 Megohms. You want to measure the pins of F121, not the sockets of the matching connector. Measure the resistance between a good ground (such as the battery negative terminal) and pin #2 of connector F121. On my car this is the highest of the two pins, the one closest to the front of the car. The factory spec is 500 - 620 Kohms. The manual says you have to remove the intake manifold to replace the KS. However, I think that a person with good dexterity and a 10mm ratcheting box wrench could replace the KS without disturbing the manifold.


P0115 and P0125 are the same thing....

P0115 = DTC 0103 = P0125 = DTC 0908 = Engine coolant temperature sensor or circuit fault

DTC 0103

Diagnostic Trouble Code 0103 points to the Engine Coolant Temperature Sensor.

The factory service manualsays this DTC is set when the ECTS signal has an excessively high or low voltage. It suggests testing the ECTS and also the associated electric connector and wiring harness. On the 4th Generation Maxima engine the Engine Coolant Temperature Sensor is located in the water outlet tube close to the engine end of the upper radiator hose. There are two sensors in that area. The one nearest the hose is for the dashboard temperature gauge. The ECTS, the one you're interested in, is right next to the the gauge sending unit. There is a good picture of these sensors in the Haynes manual on page 3-7.

With the engine cold, disconnect the ECTS and measure its resistance. Reconnect the ECTS, start the engine, run it until fully warmed up. Stop the engine, and repeat the resistance measurement. The "warm" reading should be a much lower value than the "cold" reading.

The specs for the ECTS are:

Engine coolant temperature 68F, ECTS resistance 2.1 - 2.9 Kohms
Engine coolant temperature 194F, ECTS resistance 0.24 - 0.26 Kohms

DTC 0908

Diagnostic Trouble Code 0908 indicates a bad Engine Coolant Temperature Sensor, or a defect in the connector
or wiring.

The ECTS always said "cold engine" and this prevented the Engine Control Module (the computer) from going into closed loop mode. This could indicate a bad sensor or a stuck-open thermostat. Does your heater deliver lots of hot air within three minutes of a cold start? If not, you may have a bad thermostat.

You may want to test your Engine Coolant Temperature Sensor. This is easy enough, requiring only an ohmmeter.

On the 4th Generation Maxima engine the Engine Coolant Temperature Sensor is located in the water outlet tube close to the engine end of the upper radiator hose. There are two sensors in that area. The one nearest the hose is for the dashboard temperature gauge. The ECTS, the one you're interested in, is right next to the the gauge sending unit. There is a good picture of these sensors in the Haynes manual on page 3-7.

With the engine cold, disconnect the ECTS and measure its resistance. Reconnect the ECTS, start the engine, run it until fully warmed up. Stop the engine, and repeat the resistance measurement. The "warm" reading should be a much lower value than the "cold" reading.

The Chilton Maxima shop manual gives these specs:

Engine coolant temperature 68F, ECTS resistance 2.1 - 2.9 Kohms

Engine coolant temperature 194F, ECTS resistance 0.24 - 0.26 Kohms (Roughly a factor of ten difference.)

As you can probably tell, the other two codes you got allude to the same problem with your ECTS. It wouldn't hurt to bench test it with an ohmmeter to make sure it's ok.

It's always good when you get the codes to clear the ECU and make sure they consistently appear. In the case of the ECTS, it's easy enough to check. With a $$$ part like a knock sensor, it's best to reset and make sure.