Toyota Tundra or Tacoma with Code P106B Secondary Air Injection Pressure Sensor Correlation

Lewis

Moderator
Staff member
If you get this P106B code in one of your Toyota vehicles like the Tundra or Tacoma, you will want to understand how the ECM determines whats at fault.

There are 3 pressure sensors that perform a self check 50 minutes after your truck is shut off. One of the sensors is the EVAP pressure sensor in the charcoal canister.

The other two are the pressure sensors in the air switching valves. If during the check there is a significant difference between the readings of those sensors, the ECM interprets that as a malfunction and sets the P106B code.

To find out which sensor is faulty, you need a good scan tool (such as the Toyota Techstream, a snap-on or mac scanner, not a basic code checker) that can read the ECM data list.

Look at the pressure readings from the Freeze Frame Data (stored code)
**You may not see the Vapor Pressure Pump reading in the FF stored data as Toyota didn't seem to capture it. At least from what I've seen. You can still look at the Live Data (current) and see what its reading. It may be in/around 762mmhg (convert if needed)

Vapor Pressure Pump sensor
Air Pump Pressure sensor (Absolute)
Air Pump2 Pressure sensor (Absolute)


If any one of the values differs from the atmospheric pressure by +/- 3.5 kPa (+/- 26.25 mmHg) or more, there is a malfunction in that sensor. If the vapor pressure sensor is faulty, replace the charcoal canister. If one of the air pump sensors is faulty, replace the corresponding air switching valve.

Here is what the valve in question looks like..

Toyota 25701-38100 Air Pump Switching Valve


In this example (V8), the FF Data shows us that Air Pump Pressure (Bank 1) is the culprit with a reading of -1 (the reading of -1 is equal to 51.71mmhg which is almost twice the threshold limit)

i-fz3qCZ4.jpg


Here is the Secondary Air Injection Valve for Bank 1....

i-Cttdc35-L.jpg


If we open it up and look, this is what we find....

i-7KvXP58-M.jpg


The bank 2 valve was also inspected and found to be also in need of replacing (customer requested)....

i-rTtfCvg-L.jpg


If you have a V6 engine, the valve set with come as an assembly (meaning both are included and cannot be purchased separately)...


i-jDt8Hpq-L.jpg
 
M

Mike 225

Guest
I have the P106B code on my 2012 Tundra 4.6L. My reader shows that the following
Air Pump Pressure 1 13.485 psi (converted to 697 mmHg)
Air Pump Pressure 2 14.500 psi (converted to 749 mmHg)
This tells me that Air Pump Pressure 1 is the culprit.
I've read mixed answers as to which valves are bank 1 and bank 2.
Is this in fact the drivers side? Which I believe to be part # 25702-38050
Or is it the passenger side?

Thanks for your help!
 
M

Mike225

Guest
All Toyota V8 engines are Bank 1 is Drivers side while Bank 2 is Passengers side.

Great, thank you for clarifying! I'm glad I checked. I almost ordered the part number shown in the original post (25701-38100). It looks like I need the other one.
 
K

Kevin

Guest
I would recommend replacing both sides. My CEL came on along with Trac OFF flashing and LO4 flashing. I ran an ordinary OBD2 scanner and the P106B code popped up. I didn't have a fancy scanner to tell me which bank was faulty, so I replaced both. I opened both old parts up and both were in bad shape with oxidation and moisture (6 year old Tundra with 70k miles). The driver's side (bank 1) was in worse shape, but both were pretty bad. For a part that's less than $200, replace both so you don't get the same CEL light in the near future.
 
G

Gary

Guest
This is a very good forum answered my questions from just reading past comments thanks and keep up the good work you’ve really been a big help to me and I’m sure countless others
 
R

Rich

Guest
I have a 2012 Tundra 4.6, my TRAC OFF light came on as well as the CHECK ENG light. They goes off when I reach a half tank. The codes that were pulled are C1201, P106B, P2440. The truck seems very sluggish and is not shifting properly, (automatic) without letting my foot off the gas then accelerating again.
 
R

Riggs

Guest
I have a 2012 Tundra 4.6, my TRAC OFF light came on as well as the CHECK ENG light. They goes off when I reach a half tank. The codes that were pulled are C1201, P106B, P2440. The truck seems very sluggish and is not shifting properly, (automatic) without letting my foot off the gas then accelerating again.
Same
 
H

Hannah

Guest
I have a 2012 tundra and the code is p106b, I just wanna know how much is it to get this fixed.
 
H

Hewitt Tech

Guest
I have a 2012 tundra and the code is p106b, I just wanna know how much is it to get this fixed.
A lot of the time it is a damaged pressure sensor in the secondary air switching valves. This happens when the vehicle is driven with air switching valve stuck open codes. The only way to confirm which of the three sensors is causing the code is to compare the 2 AIP (air injection pressure) values and the evap pressure sensor value. Pretty much it will always be one of the air switching valve that had a valve stuck open code. The sensor that is reading more than 5-6kPa different than the other two on the freeze frame data needs to be replaced. This could mean replacing the air switching valve or the evap canister.
 
T

Timothy Nizza

Guest
About a month ago the check engine, traction control light came on as solid and the 4 Lo light was blinking. The vehicle was NOT in limp mode.

I initially tried to clear the ECM by disconnecting the battery and connecting the positive and negative wires together.

3 days later, the lights returned. I took it to Advanced Auto for them to read my code and the code that popped was P106B and according to their system, that was the Fuel Vapor Canister Sensor and that I would have to replace the fuel vapor cannister.

After researching some forums I decided to do further research which I ended up purchasing the Aftermarket (Dorman) SAIR valve switches and installed both banks.

Once installed the vehicle was in limp mode and the code P106B went away but code P2433 P2438 and P0415 popped.

I reinstalled the old switching banks and all the codes went away but P106B popped. (BTW they looked worse then the ones in your picture)

Either way I’m assuming that this is because of one or both of the two things 1. The Dorman pumps valve switches are of substandard quality and/or 2. I should of also replaced the pumps as well. And possibly... the cannister...

My plan is to purchase OEM switches and pumps and the new snorkel and replace and if need be... the cannister....

THoughts?
 
P

Peter

Guest
I have a 2012 Tundra 4.6, my TRAC OFF light came on as well as the CHECK ENG light. They goes off when I reach a half tank. The codes that were pulled are C1201, P106B, P2440. The truck seems very sluggish and is not shifting properly, (automatic) without letting my foot off the gas then accelerating again.
Did you manage to fix it?
 
W

Woo

Guest
My 2012 Tundra with 4.6L V8 has code P106B with Check Engine and Trac off light both on. Had it checked today.. $3100 to fix. Yak
 
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Andy

Guest
I have a 2012 Toyota Tacoma that this happens a lot to as of lately. First time was last year 8/2022. I ended up getting an aftermarket secondary air injection bypass, cost me nearly $800. It is the all in one piece. My mechanic said I'll never have a problem again. Well, here it is 9/2023 and I'm having same problem with it, but I couldn't leave it with him cause I needed it to get to work. I went with aftermarket part cause Toyota said they wouldn't warranty their part but for 90 days. So I have to disconnect positive and negative wires, wait 10 min, place back on battery and all codes have been cleared, along with all my preset radio stations, etc.
 
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Bam

Guest
I have a 2012 Toyota Tacoma that this happens a lot to as of lately. First time was last year 8/2022. I ended up getting an aftermarket secondary air injection bypass, cost me nearly $800. It is the all in one piece. My mechanic said I'll never have a problem again. Well, here it is 9/2023 and I'm having same problem with it, but I couldn't leave it with him cause I needed it to get to work. I went with aftermarket part cause Toyota said they wouldn't warranty their part but for 90 days. So I have to disconnect positive and negative wires, wait 10 min, place back on battery and all codes have been cleared, along with all my preset radio stations, etc.
I am experiencing same issues. Bought and installed hewitt by pass, drove 2k miles and malfunctioning again! They do warranty the parts but ridiculous to only get 2k miles and have the same issue again!
 
B

Bam

Guest
I am experiencing same issues. Bought and installed hewitt by pass, drove 2k miles and malfunctioning again! They do warranty the parts but ridiculous to only get 2k miles and have the same issue again!
2011 tundra 4.7 V8 !
 
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