p0051...

I need help... My check engine light is on and canʻt turn it off. I have a 2008 sport v6. put the dtlt on and I have the code p0051 now. I have replaced the a/f ratio sensor already and I checked the a/f sensor heater fuse and the relay. All were in good condition. Could it be my wiring? But how? Any suggestions? Thank you in advance.

 

The 0051 code is for an open circuit. I would check your connection at the o2 sensor and make sure it isn't something like a loose connection. If that doesn't work, I would take your favorite DVOM and start trying to figure out why you have an open circuit.

BTW, I'm not following you on the dtlt Fill me in on the lingo.

 

^^^ what he said!

I just noticed that you said something about wiring. What kind of wiring were you doing? This could vary well be the issue at hand, being the trouble code you posted is for an open circuit.

 

Welcome to tw!

 

Thats what I was thinking! What was that old saying, "You snooze, you lose."



I remembered after posting that a lot of your less expensive a/f sensors do not come with the harness. I imagine this would explain for the open. Probably just a loose crimp or something along the lines of that.

 

First of all, I put in DTLT or doug thorley long tubes. Ever since then, I have been getting this p0051 code. Also, what is open circuit? I only touched the wires for the urd maf cal. Oh and the a/f sensor did come with the harness. Got it from Toyota of Dallas I believe. Thanks for the input guys.

 

Yes I am running an o2 sim, the empire o2 sim.

 

ok, thanks chris, will try that.

 

If everything is well with the wiring, you might check the o2 sim. Check it for proper resistance to see if it reads within factory specifications for what the o2 sensor should read.


This attachment from the FSM should help you some. If all these are a go, you have a problem with your o2 sim.

 

ok, i have to ask this question as well. would a leaking header be the cause of this p0051? I have a leak on the driver side between the header and y pipe.

 

A leak should no effect on the P0051.




Reasons that a P0051 code would be given:
Air-Fuel Ratio (A/F) sensor heater current less than 0.8 A
(1 trip detection logic)


Causes:
• Open in A/F sensor heater circuit
• A/F sensor heater
• A/F sensor heater relay
• ECM



If you have not had the chance to read the diagnostic procedure I attached to my above post, take a good look at it. Once you go through all the checks, if you still have a problem post some more information on what you have done to diagnose the issue, your results and etc. I'm pretty confident you have some faulty wiring somewhere (if the sensor has been modified or replaced recently). If the sensor is new there is also the possibility that it is faulty, although this is rare.

 

If you have any questions, feel free to ask.


I should have also added what an 'open' is in the electrical world. An 'open' is a very simple concept. You have an open circuit whenever power is not completing its cycle. A easy way to describe this would be if you had a light bulb with two wires leading to the + and - terminals. If you snip either of the wires, or both, the circuit becomes 'open.' Prior to the circuit being cut, it was closed because power was completing its natural cycle.

Hopefully this will help you out a bit in solving your problem and understanding the terminology on the .pdf. All of the stuff you probably already know, but is just in a technical form. You will also need an instrument that reads Ohms in order to properly diagnose your problem. I personally like to use a Sperry digital volt ohm meter(multimeter). This is just my personal preference.