SAIS and Steering Angle Sensor Issue - 2009 Tacoma 4x2.7 2WD

Hey y'all!

I drive a base 2009 Toyota Tacoma Regular Cab 2WD 4x2.7. The check engine and slip indicator lights were randomly triggered last week, but there was no noticeable difference in the way that my truck was driving (e.g. no limp mode). I took my truck into AutoZone for a diagnostic check. The technician pulled the following DTCs:

Secondary Air Injection System (SAIS)

• P0418: Secondary Air Injection System Relay A Control Circuit
  
• P2441: Secondary Air Injection System Switching Valve Stuck Closed Bank1
  
• P2445: Secondary Air Injection System Pump Stuck Off Bank1

Steering Angle Sensor

• C1440: Steering Angle Sensor Unusual Bank Angle Detected
  
• U0126: Lost Communication With Steering Angle Sensor Module

General

• C1201: Engine Control System Malfunction / EV Control System Malfunction

Since the codes were all triggered at the same time, I figured that the issue could have been due to a faulty battery or blown fuse. I cleaned a small amount of corrosion off of the battery terminals and then checked the voltage, which was at a healthy 13.4v. After disconnecting my battery, the CEL and slip indicator lights were cleared temporarily, but returned after a day of normal driving. So the battery does not seem to be the culprit.

I also checked the engine fuses and cabin fuses but did not find any blown fuses. I was not able to check the amperage of any of the fuses so there's a chance that one of the fuses is faulty, but not blown. The wiring harnesses were all securely mounted and I didn't notice any visible signs of damage to the wiring.

I checked some older posts on the forum and found some posts suggesting that the check engine and slip indicator lights could be triggered by a faulty gas cap. However, there are no obvious signs of damage to my gas cap and I confirmed that it was screwed in tightly when the CEL and slip indicator lights returned.

I found a thread related to the SAIS that referenced similar DTCs - the issue was resolved after installing a Hewitt Secondary Air Bypass Kit. However, since several DTCs related to systems outside of the SAIS were triggered at the exact same time, I think the issue is more of an electrical issue than an actual SAIS issue and don't think that installing a bypass kit is the right solution for me.

Has anyone encountered anything similar? What additional troubleshooting steps should I take to get a better idea of what the root cause may be? I'm planning on driving from Texas to Colorado in a few days and want to avoid bringing my truck into the shop for lengthy repairs if I can avoid it. Ultimately, I'm trying to figure out if it'd be safe for me to make the drive and get my truck looked at in Colorado to avoid any delays to my trip. However, if the problem I've described is cause for genuine concern, then I'll certainly get things resolved prior to my trip.

 

I'm thinking the C1440 and U0126 are unrelated to the rest of them, I wouldn't worry with those just yet.
C1201 will set in the ABS module any time there are codes in the PCM, it will self clear once the PCM codes are fixed.

Based on the other codes I'm thinking the air pump may have died, do you hear it running on a cold start like it should?

 

@Dm93 No I haven't done that yet and honestly I don't really know what to listen for. What should I be looking/listening for to figure out whether the air pump is running on a cold start? I appreciate your help!

 

It sounds like a vacuum cleaner running under the hood when it's on, it will only run during a cold start for 30-60 secs.
The pump lives behind the passenger side headlight, you can also unplug it, jump power and ground to it, and see if it runs.

 

Got it, that's super helpful. I'll take a look and report back as soon as I get the chance.

 

I found the pump and opened up the hood to listen to it right after I cold started the truck. I've got a squeaky belt right next to that pump so it was a little tough to hear, but it definitely sounded like it was running. The pump sounded like it could have been a little weak but I don't have a reference for what it sounds like when it's running as expected.

 

Pop the covers off and see if the foam filter is still in there, hopefully it didn't get sucked into the valve.

 

Yeah you're right, definitely an issue with the pump - I'm going to replace it. Found a couple options for a replacement on Amazon, for anyone looking:

• $63 RANSOTO 17600-0C020 New secondary Air Pump Compatible with 2005-2015 Toyota Tacoma 2.7L L4, Replaces 176000C020 176100C020
  17600-0C020 New Secondary Air Pump Compatible with 2005-2015 Toyota Tacoma 2.7L L4
  
• $78 NOVAPARTS 17600-0C020 Secondary Air Injection Pump Smog Pump for 2005-2015 Toyota Tacoma Base Pre Runner 2.7L L4 17610-0C020
  NOVAPARTS 17600-0C020 Secondary Air Injection Pump Smog Pump for 2005-2015 Toyota Tacoma Base Pre Runner 2.7L L4

Do I need to worry about the steering angle sensor codes? It's weird that those got triggered at the same time as the SAIS codes.

• C1440: Steering Angle Sensor Unusual Bank Angle Detected
• U0126: Lost Communication With Steering Angle Sensor Module

 

If they are persistent we will need to address them but I'd get the engine codes sorted first.