Waveform

Heated oxygen (HO2) sensor WAVEFORM REFERENCE CHART

ECM Terminal Names

Between OX1B (OX2B) and E2

Tester Ranges

0.2 V/DIV, 200 msec./DIV.

Conditions

Engine speed maintained 2,500 rpm for 2 minutes after warming up sensor

HINT:

In the DATA LIST, item O2S B1S2 shows the ECM input values from the heated oxygen sensor.

2007 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Sequoia

Ground

Ground

, r— . ,,,,

1-1-

-L, I.I J

200 msec,/DtV-

Fig. 24: Heated Oxygen (HO2) Sensor Waveform Graph 11. WAVEFORM 11 Engine speed signal WAVEFORM REFERENCE CHART

ECM Terminal Names

Between TACH and E1

Tester Range

5V/DIV., 10msec./DIV.

Condition

The wavelength becomes shorter as engine rpm increases. 5 V/DIV.

Ground

Fig. 25: Engine Speed Signal Waveform Graph

Fig. 25: Engine Speed Signal Waveform Graph

DIAGNOSIS SYSTEM 1. DESCRIPTION

When troubleshooting On-Board Diagnostics (OBD II) vehicles, the intelligent tester (complying with SAE J1987) must be connected to the Data Link Connector 3 (DLC3) of the vehicle. Various data in the vehicle's Engine Control Module (ECM) can then be read.

OBD II regulations require that the vehicle's on-board computer illuminate the Malfunction Indicator Lamp (MIL) on the instrument panel when the computer detects a malfunction in:

2007 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Sequoia a. The emission control systems components b. The powertrain control components (which affect vehicle emissions)

c. The computer itself

In addition, the applicable Diagnostic Trouble Codes (DTCs) prescribed by SAE J2012 are recorded in the ECM memory. If the malfunction does not recur in 3 consecutive trips, the MIL turns off automatically but the DTCs remain recorded in the ECM memory.

To check the DTCs, connect the intelligent tester to the DLC3. The tester displays DTCs, freeze frame data, and a variety of engine data. The DTCs and freeze frame data can be erased with the tester. In order to enhance OBD function on vehicles and develop the Off-Board diagnosis system, the Control Area Network (CAN) communication is used in this system. It minimizes the gap between technician skills and vehicle technology. CAN is a network which uses a pair of data transmission lines that span multiple ECUs and sensors. It allows high speed communication between the systems and simplifies the wire harness connections. The CAN Vehicle Interface Module (CAN VIM) must be connected with the intelligent tester to display any information from the ECM. The intelligent tester and ECM uses CAN communication signals to communicate. Connect the CAN VIM between the intelligent tester and DLC3.

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