SAIS Failure and Trouble Codes

Any SAIS component failure generally sets the check engine light (CEL) and causes the Engine Control Module (ECM) to store trouble codes, many of which are caused by a failing SAIS air pump. 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", which is when throttle response is limited to 50% to protect the engine from damage.

The codes below are the most common trouble codes that can be cleared once a Hewitt-Tech bypass kit is installed and the codes are initially reset. After the kit is installed, the system is prevented from operating and the codes below should not come back on, set the CEL or let the vehicle enter "limp mode". Call us TOLL-FREE at 1-844-307-7671 for more details about codes that Hewitt-Tech bypass kits can or cannot clear.

Codes Hewitt-Tech Bypass Kits (V36W, V36H or V52H) Can Clear*

P1441 - Switching Valve No.2 Stuck Open Bank 1
P1442 - Switching Valve No.2 Stuck Close Bank 1
P1444 - Switching Valve No.2 Stuck Open Bank 2
P1445 - Switching Valve No.2 Stuck Close Bank 2
P2440 - Switching Valve Stuck Open Bank 1
P2441 - Switching Valve Stuck Closed Bank 1
P2442 - Switching Valve Stuck Open Bank 2
P2443 - Switching Valve Stuck Closed Bank 2
P2445 - Pump Stuck OFF Bank 1
* Important cold weather note, see below in red.
P2447 - Pump Stuck Off Bank 2

*A blown air pump fuse or damaged air pressure sensors are exceptions that need to be addressed at the same time to ensure the Hewitt-Tech bypass module works.

Non-SAIS Codes

Before installing the Hewitt-Tech bypass module, we highly recommend that you address codes not related to the SAIS. In general, the Hewitt-Tech SAIS bypass kit cannot clear codes related to electrical faults or circuit malfunctions. However, the few codes below can be cleared with the Hewitt-Tech SAIS bypass kit, but only under certain circumstances with the addition of a Pump Replacement Pack or a Pressure Sensor Replacement Harness.

Codes Hewitt-Tech Bypass Kits Can Clear by Adding a Pressure Sensor Replacement Harness (PSRH)*

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
P106B - Pressure Sensor Correlation / Evap. Pressure Sensor

*A damaged pressure sensor is usually caused by an air switching valve being stuck open for a long period of time. If you are getting codes for both Bank 1 and Bank 2 pressure sensors, we have a custom double harness that can also be found on the Kit Add On page.

Codes Hewitt-Tech Bypass Kits Can Clear by Adding One or Two Pump Proxy Packs (PPP)*

P0418 - SAIS Circuit/Relay 'A' Circuit Malfunction Bank 1
P0419 - SAIS Circuit/Relay 'A' Circuit Malfunction Bank 2

*These codes are usually caused by an open or short circuit in one of the air pumps. One pack is needed for each code..

Codes Hewitt-Tech Bypass Kits Can Clear by Adding One or Two Valve Replacement Packs (VRP)*

P0412 - SAIS Switching Valve 'A' Circuit Malfunction Bank 1
P0415 - SAIS Switching Valve 'A' Circuit Malfunction Bank 2

*These codes are usually caused by an open circuit of the solenoid coil in one of the air switching valves (A = Bank1 ASV Solenoid, B = Bank2 ASV Solenoid). One pack is needed for each code.





Explanations, Exceptions and Other Codes


C1201 - Engine Control System Malfunction
This is the"limp mode"code that indicates your VSC, TRAC and other safety systems have been turned off. Not all scanners can read the C codes, but they are probably there if you are in "limp mode". Do not worry - this code clears when you install a Hewitt-Tech bypass kit to clear other trouble codes.

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 cold weather 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 the ECM glitch. This glitch has been confirmed to happen on vehicles with and without the Hewitt-Tech module installed, as well as on vehicles with no other SAIS problems.

The only known solution for this cold weather glitch is a correct update (calibration file) for your ECM. However, finding the service bulletin or limited service campaign for the correct calibration file is virtually impossible as both have been removed from the Toyota Information System. The cold weather service bulletin was likely deleted after the current P0418/P2445 bulletin came out, which directs service managers and techs to replace the entire system with no indication of an ECM update. Replacing the entire air system will not correct the problem even though the air injection control driver has a new part number. Currently, there are only two viable remedies to the cold weather P2445 issue. The first is to carry an OBDII tool so that you can just pull over, clear the code and keep driving. The other option is performing a cold start warmup and shutdown before needing to get up to 50 mph or faster. The vehicle can also be started and driven for a short while before being shut down and restarted as long as it is before exceeding 50 mph. Basically, starting a new drive cycle with a warm engine stops the P2445 code from displaying when you go fast enough. Call us TOLL-FREE at 1-844-307-7671 for more information or if you have questions about these procedures. We hope to build these work-around procedures into our Hewitt-Tech bypass modules.

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 will show even after you install the Hewitt-Tech bypass module and clear the codes.

Call us TOLL-FREE at 1-844-307-7671 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