- Pressure sensor
- Open or short in pressure sensor circuit
- ECM
| Last Modified: 11-29-2007 | 1.6 C | |
| Service Category: Engine/Hybrid System | Section: Engine Control | |
| Model Year: 2008 | Model: Sequoia | Doc ID: RM0000013HB00IX |
| Title: 2UZ-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia) | ||
|
DTC |
P2431 |
Secondary Air Injection System Air Flow / Pressure Sensor Circuit Range / Performance Bank1 |
|
DTC |
P2432 |
Secondary Air Injection System Air Flow / Pressure Sensor Circuit Low Bank1 |
|
DTC |
P2433 |
Secondary Air Injection System Air Flow / Pressure Sensor Circuit High Bank1 |
|
DTC |
P2436 |
Secondary Air Injection System Air Flow / Pressure Sensor Circuit Range / Performance Bank 2 |
|
DTC |
P2437 |
Secondary Air Injection System Air Flow / Pressure Sensor Circuit Low Bank 2 |
|
DTC |
P2438 |
Secondary Air Injection System Air Flow / Pressure Sensor Circuit High Bank 2 |
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 |
|---|---|---|
|
P2431 P2436 |
Pressure sensor indicates less than 45.6 kPa (342 mmHg), or more than 135 kPa (1013 mmHg) (2 trip detection logic) |
|
|
P2432 P2437 |
While engine running, voltage output of pressure sensor remains below 0.5 V (1 trip detection logic) |
|
|
P2433 P2438 |
While engine running, voltage output of pressure sensor remains above 4.5 V (1 trip detection logic) |
|
MONITOR DESCRIPTION
The ECM monitors the pressure in the secondary air passage using the pressure sensor located on the air switching valve in the secondary air injection system.
If there is a defect in the sensor or the sensor circuit, the voltage level deviates from the normal operating range, the ECM interprets this deviation as a malfunction in the pressure sensor or circuit and stores a DTC.
MONITOR STRATEGY
|
Related DTCs |
P2431: Air flow/Pressure sensor circuit rationality P2432: Air flow/Pressure sensor circuit range check (Low voltage) P2433: Air flow/Pressure sensor circuit range check (High voltage) P2436: Air flow/Pressure sensor circuit rationality P2437: Air flow/Pressure sensor circuit range check (Low voltage) P2438: Air flow/Pressure sensor circuit range check (High voltage) |
|
Required Sensors/Components (Main) |
Pressure sensor |
|
Required Sensors/Components (Related) |
- |
|
Frequency of Operation |
Continuous |
|
Duration |
P2432, P2433, P2437 and P2438: 0.5 seconds P2431 and P2436: 5 seconds |
|
MIL Operation |
P2432, P2433, P2437 and P2438: Immediate P2431 and P2436: 2 driving cycles |
|
Sequence of Operation |
None |
TYPICAL ENABLING CONDITIONS
P2432, P2433, P2437 and P2438
|
Monitor runs whenever following DTCs not present |
None |
|
All of following conditions met: |
- |
|
Starter |
OFF |
|
Battery voltage |
8 V or more |
|
Ignition switch |
ON |
P2431 and P2436
|
Monitor runs whenever following DTCs not present |
P2432, P2433, P2437, P2438 (AIR Pressure Sensor - Low/High) |
|
Starter |
OFF |
|
Battery voltage |
8 V or more |
|
Ignition switch |
ON |
TYPICAL MALFUNCTION THRESHOLDS
P2432 and P2437
|
Air pressure sensor voltage |
Less than 0.5 V |
P2433 and P2438
|
Air pressure sensor voltage |
More than 4.5 V |
P2431 and P2436
|
Air pressure |
Less than 45.6 kPa (342 mmHg), or more than 135 kPa (1013 mmHg) |
COMPONENT OPERATING RANGE
|
Air pressure sensor voltage |
Between 0.5 V and 4.5 V |
WIRING DIAGRAM
Refer to DTC P0412
.
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the Techstream. Freeze frame data record 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. |
CHECK HARNESS AND CONNECTOR (PRESSURE SENSOR - ECM) |
(a) Disconnect the air switching valve connector.
(b) Disconnect the ECM connectors.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
D37-3 (AIP) - A27-54 (AIP) |
Always |
Below 1 Ω |
|
D37-2 (VC) - D56-66 (VC) |
Always |
Below 1 Ω |
|
D37-4 (E2) - D56-98 (ETHA) |
Always |
Below 1 Ω |
|
D38-3 (AIP2) - A27-53 (AIP2) |
Always |
Below 1 Ω |
|
D38-2 (VC2) - D56-66 (VC) |
Always |
Below 1 Ω |
|
D38-4 (E22) - D56-97 (ETHW) |
Always |
Below 1 Ω |
|
D37-3 (AIP) or A27-54 (AIP) - Body ground |
Always |
10 kΩ or higher |
|
D37-2 (VC) or D56-66 (VC) - Body ground |
Always |
10 kΩ or higher |
|
D38-3 (AIP2) or A27-53 (AIP2) - Body ground |
Always |
10 kΩ or higher |
|
D38-2 (VC2) or D56-66 (VC) - Body ground |
Always |
10 kΩ or higher |
|
|
2. |
INSPECT AIR SWITCHING VALVE (PRESSURE SENSOR) |
(a) Connect a pressure gauge to the air pressure sensor as shown in the illustration.
(b) Connect the Techstream to the DLC3.
(c) Turn the ignition switch to ON.
(d) Turn the Techstream ON.
(e) Enter the following menus: Powertrain / Engine / Data List / Air pump pressure (absolute) and Air Pump2 Pressure (Absolute).
(f) Check that the pressure displayed on the Techstream fluctuates when applying the pressure to the pressure sensor with the pressure gauge.
OK:
Pressure fluctuates in response to pressure applied with pressure gauge.
Result
|
Result |
Proceed to |
|---|---|
|
Within standard range |
A |
|
Outside standard range (for Bank 1) |
B |
|
Outside standard range (for Bank 2) |
C |
HINT:
The Techstream displays the air pump pressure as absolute pressure.
|
|
|