After cold engine starts, all of following conditions met (1 trip detection logic):
| Last Modified: 11-29-2007 | 1.6 C | |
| Service Category: Engine/Hybrid System | Section: Engine Control | |
| Model Year: 2008 | Model: Sequoia | Doc ID: RM0000012FY00JX |
| Title: 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia) | ||
|
DTC |
P0412 |
Secondary Air Injection System Switching Valve "A" Circuit |
|
DTC |
P0415 |
Secondary Air Injection System Switching Valve "B" Circuit |
DESCRIPTION
The Secondary Air Injection (AIR) system consists of an air pump, the Air Switching Valve (ASV), a pressure sensor, the Air Injection Control Driver (AID) and the ECM. For a short time after cold engine starts, the AIR system pumps secondary air to the exhaust port of the cylinder head to purify the exhaust emissions. The secondary air is supplied by the air pump and is pumped to the exhaust port through the ASV.
The AID drives the ASV and the air pump according to command signals transmitted by the ECM. The pressure sensor detects the pressure in the secondary air passage when the AIR system is ON and OFF, and transmits a pressure signal to the ECM.
The AID is not only equipped to drive the pump and valve, but also with a diagnosis function to detect malfunctions in the AIR system circuit.
HINT:
As a large current is required to drive the air pump and ASV, an AID is installed to this system.
|
DTC No. |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
P0412 P0415 |
|
|
|
P0412 P0415 |
After cold engine starts, all of following conditions met (1 trip detection logic): |
|
MONITOR DESCRIPTION
The Air Injection Control Driver (AID) detects open and short circuits according to the voltages of the air pump terminal (VP) and the Air Switching Valve (ASV) terminal (VV), and transmits diagnostic information as a signal to the ECM.
For a short time after cold engine starts, the ECM transmits command signals to the AID to drive the air pump and ASV.
The AID transmits an ASV malfunction signal to the ECM if either of the following conditions is met:
- The voltage at the AID terminal relating to the ASV is low despite the AID receiving command signals from the ECM to drive the ASV.
- The voltage at the AID terminal relating to the ASV is high despite the AID receiving no command signals from the ECM to drive the ASV.
The ECM stores the DTC based on diagnostic signals from the AID.
MONITOR STRATEGY
|
Related DTCs |
P0412: Secondary air injection system air switching valve circuit range check (Bank 1) P0415: Secondary air injection system air switching valve circuit range check (Bank 2) |
|
Required Sensors/Components (Main) |
Air injection control driver |
|
Required Sensors/Components (Related) |
Air switching valve |
|
Frequency of Operation |
Once per drive cycle |
|
Duration |
3 seconds |
|
MIL Operation |
Immediate |
|
Sequence of Operation |
None |
TYPICAL ENABLING CONDITIONS
Case 1
|
Monitor runs whenever following DTCs not present |
- |
|
Secondary air injection pump |
Operating |
|
Secondary air injection switching valve |
Operating |
|
Battery voltage |
8 V or more |
|
Ignition switch |
ON |
|
Starter |
OFF |
Case 2
|
Monitor runs whenever following DTCs not present |
- |
|
Secondary air injection pump |
Not operating |
|
Secondary air injection switching valve |
Not operating |
|
Battery voltage |
8 V or more |
|
Ignition switch |
ON |
|
Starter |
OFF |
TYPICAL MALFUNCTION THRESHOLDS
|
Diagnostic signal duty ratio from air injection control driver |
31% or more, and 48% or less |
COMPONENT OPERATING RANGE
|
Diagnostic signal duty ratio from air injection control driver |
70% or more, and 90% or less when secondary air injection system operating. 0% when secondary air injection system not operating. |
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
The diagnostic information output from Air Injection Control Driver (AID) can be confirmed by connecting an oscilloscope to the diagnostic information terminal of the AID. Reading the waveform while performing the AIR system intrusive operation provided in the System Check function allows the possible trouble areas to be narrowed down.
NOTICE:
-
This Air Injection Check only allows technicians to operate the AIR system for a maximum of 5 seconds. Furthermore, the check can only be performed up to 4 times per trip. If the test is repeated, intervals of at least 30 seconds are required between checks. While AIR system operation using the Techstream is prohibited, the Techstream display indicates the prohibition (WAIT or ERROR).
If an ERROR is displayed on the Techstream during the test, stop the engine for 10 minutes, and then try again.
- Performing the Air Injection Check repetitively may cause damage to the AIR system. If necessary, leave an interval of several minutes between System Check operations to prevent the system from overheating.
- When performing the Air Injection Check operation after the battery cable has been reconnected, wait for 7 minutes with the ignition switch turned to ON or the engine running.
- Turn the ignition switch off when the Air Injection Check operation finishes.
|
AID Diagnostic Signal Waveform |
ECM Command |
DTC (ECM Output) |
Suspected Trouble Area |
|---|---|---|---|
|
100% Duty Ratio 
|
Any Secondary Air Injection (AIR) System operation |
P1613 P1614 |
|
|
0% Duty Ratio 
|
AIR System: ON (Air pump ON, ASV ON) |
P1613 P1614 |
|
|
AIR System: OFF (Air pump OFF, ASV OFF) |
- |
Normal |
|
|
20% Duty Ratio 
|
Air Pump: ON |
P0418 P0419 |
|
|
Air Pump: OFF |
P0418 P0419 |
|
|
|
40% Duty Ratio 
|
ASV: ON |
P0412 P0415 |
|
|
ASV: OFF |
P0412 P0415 |
|
|
|
80% Duty Ratio 
|
AIR System: OFF (Air pump OFF, ASV OFF) |
P1613 P1614 |
|
|
AIR System: ON (Air pump ON, ASV ON) |
- |
Normal |
|
|
Other than above (other than 0, 20, 40, 80 and 100% duty) |
- |
P1613 P1614 |
|
HINT:
- By using the Techstream to perform the Air Injection Check operation in the System Check, the air-fuel ratio and the pressure in the secondary air injection system passage can be checked while the secondary air injection system is operating. This helps technicians to troubleshoot the system when it malfunctions.
- Read freeze frame data using the Techstream. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
PROCEDURE
|
1. |
INSPECT AIR SWITCHING VALVE ASSEMBLY |
(a) Disconnect the ASV connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
D37-5 (+B) - D37-1 (GND) |
20°C (68°F) |
4.5 to 5.5 Ω |
|
D38-5 (+BL) - D38-1 (GNDL) |
20°C (68°F) |
4.5 to 5.5 Ω |
|
|
2. |
CHECK HARNESS AND CONNECTOR (AIR SWITCHING VALVE - BODY GROUND) |
(a) Disconnect the ASV connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
D37-1 (GND) - Body ground |
Always |
Below 1 Ω |
|
D38-1 (GNDL) - Body ground |
Always |
Below 1 Ω |
|
|
3. |
CHECK HARNESS AND CONNECTOR (AIR SWITCHING VALVE - AIR INJECTION CONTROL DRIVER) |
(a) Disconnect the ASV connector.
(b) Disconnect the AID connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
D37-5 (+B) - D32-6 (VV) |
Always |
Below 1 Ω |
|
D38-5 (+BL) - D34-6 (VV2) |
Always |
Below 1 Ω |
|
D37-5 (+B) or D32-6 (VV) - Body ground |
Always |
10 kΩ or higher |
|
D38-5 (+BL) or D34-6 (VV2) - Body ground |
Always |
10 kΩ or higher |
|
|
|