SAIS Failure and Trouble Codes

Any Secondary Air Injection System (SAIS) component failure generally sets the check engine light (CEL) and causes the Engine Control Module (ECM) to store trouble codes. You will know a failing air pump is the problem when you hear a loud vacuum cleaner noise for 20-30 seconds after a cold start. Most of these mechanical failures also cause the vehicle to enter “limp mode”, where throttle input is limited to protect the engine from damage and will also prevent the transmission from shifting normally. To learn more about the different types of SAIS fault codes and more details about specific error codes, read our Blog post What Do My Error Codes Mean?

Before installing the Hewitt-Tech bypass module, we highly recommend that you address codes not related to the Secondary Air Injection System. Listed below are the most common SAIS error codes which can typically be addressed by the Hewitt Tech bypass or in combination with a kit addon. To confirm code coverage please refer to Bypass Kit Comparison Chart or specific product listing.

Mechanical SAIS Air Switching Valve and Air Injection Pump Fault Codes: (not all codes applicable to all vehicles)

P1441 – Switching Valve No.2 Stuck Open Bank 1 (vacuum actuated)
P1442 – Switching Valve No.2 Stuck Close Bank 1 (vacuum actuated)
P1444 – Switching Valve No.2 Stuck Open Bank 2 (vacuum actuated)
P1445 – Switching Valve No.2 Stuck Close Bank 2 (vacuum actuated)
P2440 – Switching Valve Stuck Open Bank 1/Main
P2441 –  Switching Valve Stuck Closed Bank 1/Main
P2442 – Switching Valve Stuck Open Bank 2
P2443 – Switching Valve Stuck Closed Bank 2
P2444 – Injection Pump Stuck On Bank 1
P2445 – Injection Pump Stuck Off Bank 1 * Important cold weather note, see below in red.
P2446 – Injection Pump Stuck On Bank 2
P2447 – Injection Pump Stuck Off Bank 2

*There is the possibility that the mechanical codes above can also be caused by things like damaged pressure sensors or wiring and may need additional troubleshooting or kit add-ons.
Most often when a pressure sensor in one of the air valves becomes damaged they tend to be damaged towards valve stuck open. Typically the only way to get a valve stuck open code after installing the block off plates is if the pressure sensor has been damaged. This sort of damage is what typically happens when driving the vehicle for too long with the valves physically stuck open, it is the exposure of the sensors to the high temperature/high moisture content exhaust that damages the sensor. Sometimes this damage can be intermittent or even have a delayed effect.

Electrical SAIS Fault Codes:

P0418 – SAIS Circuit/Relay ‘A’ Circuit Malfunction Bank 1
P0419 – SAIS Circuit/Relay ‘B’ Circuit Malfunction Bank 2

*These codes are almost always caused by an open circuit of the air pump motors themselves and not the air injection control driver according to the repair manuals. Occasionally an air pump motor can short out which can also damage the air injection control driver an they rarely blow the air pump fuse. The Gen1 kits will typically use a Pump Proxy Pack for each of these codes and potentially need an air injection control driver if was damaged.

P0412 – SAIS Switching Valve ‘A’ Circuit Malfunction Bank 1
P0415 – SAIS Switching Valve ‘B’ Circuit Malfunction Bank 2

*These codes are most often caused by an open circuit of the solenoid coil inside the air switching valves or damaged wiring between them and the air injection control drivers. The Gen1 kits will typically use a Valve Proxy Pack for each of these codes. The Gen2 kits can take care of these codes by themselves.  

P1440 – Vacuum Switching Valve (VSV) Circuit Malfunction Bank 1
P1443 – Vacuum Switching Valve (VSV) Circuit Malfunction Bank 2

*These two codes are for the vacuum switching valve circuits on certain 4.7L engine vehicles. These VSVs control the two No. 2 vacuum actuated air switching valves on. If you have one of these codes with a Gen1 kit, the wiring or VSV needs to be replaced. The Gen2-3V kits will plug into the factory connectors of these VSV which will then remain disconnected.

Pressure Sensor SAIS Fault Codes:

P2431 – Pressure Sensor Circuit Range / Performance Bank 1
P2432 – Pressure Sensor Circuit Low Bank 1
P2433 – Pressure Sensor Circuit High Bank 1
P2436 – Pressure Sensor Circuit Range / Performance Bank 2
P2437 – Pressure Sensor Circuit Low Bank 2
P2438 – Pressure Sensor Circuit High Bank 2
P106B – SAIS Pressure Sensor  / Evap. Pressure Sensor Correlation

*These codes typically indicate damage to the SAIS pressure sensor(s) or damage to their wiring. These are usually the ultimate result of sensors that have been damaged by driving with a valve stuck open codes for too long. It is also common to see some of these codes caused by wiring damage, particularly in the winter when rodents are nesting. Regardless of our bypass kits, the vehicles still require these circuits/pressure sensors to be functioning to factory specification. The Gen 1 and Gen 2 Bypass kits cannot take care of these by themselves, compatible Pressure Sensor add-ons or repair to the wiring is required for correct operation.

Explanations, Exceptions and Other Codes

C1201 – Engine Control System Malfunction

This is what we call “The” Limp Mode Code. This is a code that indicates there has been a malfunction in one of the vehicle’s control systems like the engine/transmission/emissions/traction control (TRAC), vehicle stability control (VSC), anti-lock brake system (ABS) or the safety restraint system (SRS). This is also a canbus stop command code that will turn off all of the other control systems to prevent a malfunction from affecting those safe operation of the vehicle. Anytime there is a C1201 code, there will be another code that caused it. As far as the SAIS is concerned, the valve stuck open codes and pressure sensor circuit codes will also cause the C1201 code which will will turn off the other systems. This is why the VSC and TRAC  lights also illuminate with the Check Engine Light to let you know that those systems have been deactivated for safety. Most Generic OBDII codes cannot read the C “control” codes, but if you are in limp mode, its there.  Do not worry though – this code will clear with the others.

P2445 – Pump Stuck OFF Bank 1

This code is normally caused by the secondary air injection pump not being able to create proper air pressure because the pump impeller is damaged or the air pump motor has been damaged and/or blown the air pump fuse. If the air pump motor has been damaged, it is common to also see a P0418 code that indicates this. If the air pump fuse has blown, this code will display but you may not see a P0418 code until the fuse is replaced. If you only see the P2445 code during a cold start, the Hewitt-Tech bypass kit can clear it.

*On some 2005-06 vehicles with 4.7L engines, there is a known freezing temperature glitch in the ECM that can occur when driving in near-freezing or below-freezing temperatures. If you start your vehicle in freezing temperatures, and the P2445 code displays as you near 50 mph, a glitch in the ECM is the cause. However, that is not normally how a P2445 code is thrown, and it also does not typically cause limp mode. If you have a Hewitt-Tech bypass kit installed on your vehicle, there is nothing wrong with the kit, it is a program glitch in the ECM. This glitch has been confirmed to happen on vehicles with or without the Hewitt-Tech module installed, as well as on vehicles with no other SAIS problems and even on vehicles that have had the entire secondary air injection system replaced with new.

The only known solution for this cold weather glitch is a re-flash of the computer as outlined in a very specific but no longer available limited service campaign from Toyota. This limited service campaign was specific to code P2445 coming on while driving in the same drive cycle as being started with the engine at a freezing temp. This limited service campaign expired or was intentionally removed from the system when the service bulletin for codes P0418/P2445 came out and directs the service managers and techs to replace the entire system. This would leave one to believe replacing the Air Injection Control driver with the new part number would remedy the problem but it has been proven to not be the case. Replacing the entire system does not resolved the cold weather issue as there is no computer update (re-flash) done under this service bulletin.

We have currently exhausted all ideas and efforts to resolve this freezing temp. issue and are now currently only aware 2 ways to deal with it. The first solution is an active way of preventing the glitch from occurring by using a startup/warmup/shutdown/restart sequence to prevent the freezing temperature glitch from happening. To do this it is first necessary to recognize that the engine temperature is at or below freezing at startup if the engine has been off for 7 hours or more (cold start). If so start the engine and let the engine warm up until at least the engine temperature gauge starts to move (only needs to be above freezing), turn the engine off and restart before driving or needing to drive above 50-55MPH. This will cause the engine start temperature to be freezing and in a second drive cycle which will preventing the glitch from happening when driving at 50MPH or more under the freezing start condition. The vehicle can also be started and then driven for a short while to warm it up as long as vehicle speed does not exceed 50MPH or the engine is shutoff and restarted before exceeding 50MPH. Again, this warmup/shutdown/restart cycle would only need to be performed if the temperature is at or below freezing when the vehicle has been sitting off for 7 hrs. or longer.

The other way of dealing with the issue is just to be prepared for it to happen and clear the code when it does. In many areas temperatures rarely get to freezing or below or at least do not stay there for long. In these cases it is easiest just to clear the P2445 trouble code when this happens by pulling over and using an OBDII tool or disconnecting the negative battery terminal for 5 min. Once cleared the glitch will not occur again until the first drive cycle when the vehicle has been off for 7 hrs. or more and in the first cold start drive cycle you exceed 50MPH. However, this would have to be done every time the glitch occurs to get out of limp mode.

There is still a possibility we may be able to find a solution to this freezing temp problem but currently these are the only 2 ways we know of. If you are experiencing this problem it will stop happening when your startup temperatures are again above freezing. if you have questions about these procedures call us TOLL-FREE at 1-800-307-7671.

P011B – Temperature Correlation Error

This code is caused when the temperatures for the air intake and engine coolant are not within a certain range of each other during the correlation test on a cold start. Most common cause for this code is if 2005-07 Hewitt-Tech bypass kit is installed on a 2008 or newer vehicle. The V5 and newer units are specifically designed to avoid this problem on 2008 and newer vehicles.

P106B – Pressure Sensor Correlation / Evap. Pressure Sensor

There are three pressure sensors used to compare atmospheric pressure. Two are in the secondary air switching valves, and one is the evap. pressure sensor. When one of the three is not reading the same values as the other two, the P106B code displays. P106B is usually caused by operating a vehicle when one of the air switching valves remains open and allows exhaust or moisture to leak back into the pressure sensor for a long period of time or long distance.

The only way to be certain of which sensor is causing the problem is to compare the freeze frame data for all three sensors when the code is thrown and stored. If the offending sensor is part of the SAIS, we have Pressure Sensor Replacements (direct, wired, and plug-and-play) that can be added to the Hewitt-Tech bypass kit to solve the problem without having to replace the bad air switching valve.

*The test for P106B will not run if there are air switching valve codes already present, meaning the P106B code may still come on after you install the Hewitt-Tech bypass module and clear the codes.

Call us TOLL-FREE at 1-800-307-7671 or use the Contact Us form for more information and answers to your questions about trouble codes. If using the form, please include your vehicle information and trouble codes. Our knowledgeable staff is ready and waiting to tell you what the Hewitt-Tech bypass kits can do for your situation.

SAIS and Other Trouble Codes For Reference Only.

C1201 – Engine Control System Malfunction – VSC and TR(A)C Prohibited
P0101 – MAF Circuit Range/Performance Problem
P0102 – MAF Circuit Low Input
P0103 – MAF Circuit High Input
P0111 – IAT Sensor Circuit Range/Performance Problem
P0112 – IAT Sensor Circuit Low
P0113 – IAT Sensor Circuit High
P0115 – ECT Circuit Malfunction
P0116 – ECT Circuit Range/Performance Problem
P0117 – ECT Circuit Low Input
P0118 – ECT Circuit High Input
P011B – ECT/IAT Correlation
P0412 – Switching Valve Circuit Malfunction Bank 1
P0415 – Switching Valve Circuit Malfunction Bank 2
P0416 – Switching Valve Relay Open Bank 2
P0417 – Switching Valve Relay Shorted Bank 2
P0418 – Relay ‘A’ Circuit Malfunction Bank 1
P0419 – Relay ‘A’ Circuit Malfunction Bank 2
P0420 – Catalyst System Efficiency Below Threshold Bank 1
P0430 – Catalyst System Efficiency Below Threshold Bank 2
P144C – Open in SAIS Heater Control Circuit
P144D – Short in SAIS Heater Control Circuit
P1440 – Vacuum Switching Valve Circuit Malfunction Bank 1
P1441 – Switching Valve No.2 Stuck Open Bank 1
P1442 – Switching Valve No.2 Stuck Close Bank 1
P1443 – Vacuum Switching Valve Circuit Malfunction Bank 2
P1444 – Switching Valve No.2 Stuck Open Bank 2
P1445 – Switching Valve No.2 Stuck Close Bank 2
P1603 – Engine Stall History
P1605 – Rough Idle
P1613 – Driver Malfunction Bank 1
P1614 – Driver Malfunction Bank 2
P2431 – Air Flow / Pressure Sensor Circuit Range / Performance Bank1
P2432 – Air Flow / Pressure Sensor Circuit Low Bank 1
P2433 – Air Flow / Pressure Sensor Circuit High Bank 1
P2436 – Air Flow / Pressure Sensor Circuit Range / Performance Bank 2
P2437 – Air Flow / Pressure Sensor Circuit Low Bank 2
P2438 – Air Flow / Pressure Sensor Circuit High Bank 2
P2440 – System Switching Valve Stuck Open Bank 1
P2441 – System Switching Valve Stuck Closed Bank 1
P2443 – System Switching Valve Stuck Closed Bank 2
P2444 – System Pump Stuck ON Bank 1
P2445 – System Pump Stuck OFF Bank 1
P2446 – System Pump Stuck On Bank 2
P2447 – System Pump Stuck Off Bank 2