2007 Tacoma V6 Check engine-Codes question

Hi, New here. Im not a Tacoma Owner, but I was asked to look at Our friends sons truck since it was Having issues.

Scanning it I got two Codes.
P0171 System to Lean.. I initially was thinking Mass Airflow Sensor, However this was just replaced by a mechanic two weeks ago (supposedly).

C0200 Right front Speed sensor Malfunction
C0205 Left front speed sensor Malfunction.

So I find it odd that both speed sensors would fail at the same time, so i'm looking at a common point. ABS module, etc.. I also find it odd that no ABS light is on, just a check engine light. Wouldnt the ABS light be on?

I just went through this on My 2018 ram 3500 and replaced the Hydraulic control unit for the brakes and did an ABS bleed, but the code was specific to the HCU on that truck.

It was Dark and Late last night when they brought it over so I only did a quick drive and noticed some Surging and got the codes.

Any thoughts on this is Greatly appreciated as its their Sons truck and he's young and does need it for work!

Ron

 

It's a 2007 V6?

Why was the MAS replaced?

 

Hi, Thanks for the response. It has the 4.0 in it , The MAS was replaced due to a check engine light and her son said it felt like it had a slight miss in it at slow speeds. The mechanic they took it to, first tried to clean it, and that didnt clear the CE light and so he replaced it (supposedly!), Im unsure of any codes that led him to believe that was the issue, but it is showing a lean Condition now, I suppose theoretically it could be tied to a vacuum leak somewhere in the system as well?
Im also unsure about the speed sensor codes sense the ABS light is not currently on, but I pulled those codes as well. Replacing speed sensors is easy enough but I find it hard to imagine having issues with both front sensors at the same time.

 

researching It could potentially be an O2 sensor, but those usually show a specific code for that as well in my experience, But Im admittedly not familiar with the 4.0 in the Tacoma.

 

I get a P0-500 code which is 'speed senor A'. Your codes could be related to that. Several people have told me the instrument cluster is bad and will need to be replaced for the code to be cleared for good. Check the speedo vs. your phone's GPS. If the speedo is a few MPH off it might be part of the issue.

 

Disconnect the front speed sensors.
The front RIGHT will have a Blue and Pink wire. The BLUE wire should have 7-12v on it.
The format LEFT will have a Green and Red wire. The GREEN wire should have 7-12v on it.


The lean code could be numerous things.
0171 is for bank 1 (passenger side).
Check for an exhaust leak on that side.
Possible vacuum leak too.

Other than that, you need a scan tool that can graph the A/F sensor readings.

 

Thanks for the Suggestions guys, I had thought about doing a voltage check on the Speed sensors so that is on my list of things to look into. I'll look for an exhaust leak, My daughters Trax had that issue, the pipe had broken clear in two, which I had found out is a common issue with those. Easy enough to check that and for vacuum leaks with some starting fluid, etc... Really at nearly 17 years old and 230,000 miles maybe I just replace all of the sensors anyway assuming one is fixed another wouldn't be far behind. Thoughts?

 

I don’t like replace sensors unless I know they are bad.
I always like to use OE sensors. And they are “expensive”.
Aftermarket sensors seem to cause more trouble than they are worth.
Parts quality today is horrible.