Toyota Tundra. Manual — part 1134

CAN communication signal (Reference)

WAVEFORM REFERENCE 12

HINT:

The wavelength varies depending on the CAN communication signal.

Fig. 28: Identifying Waveform 12 Reference

13. WAVEFORM 13

CAN communication signal (Reference)

WAVEFORM REFERENCE 13

HINT:

The wavelength varies depending on the CAN communication signal.

Fig. 29: Identifying Waveform 13 Reference

ECM Terminal Name Between CANH and E1

Tester Range

1 V/DIV., 10 µsec./DIV.

Condition

Ignition switch ON

ECM Terminal Name Between CANL and E1

Tester Range

1 V/DIV, 10 µsec./DIV.

Condition

Ignition switch ON

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

14. WAVEFORM 14

Terminal AID of air injection control driver

WAVEFORM REFERENCE 14

HINT:

The wavelength changes when the air injection control driver detects malfunctions in the air injection
system (See INSPECTION PROCEDURE ).

Fig. 30: Identifying Waveform 14 Reference

DIAGNOSIS SYSTEM

1. DESCRIPTION

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

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

a. The emission control systems components.

b. The powertrain control components (which affect vehicle emissions).

c. The computer itself.

ECM Terminal Name Between AIDI and E1 or AID2 and E1

Tester Range

5 V/DIV., 100 msec./DIV.

Condition

Performing Active Test using Techstream (air injection system)

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

Fig. 31: Identifying Malfunction Indicator Lamp

In addition, the applicable 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 Techstream to the DLC3. The Techstream displays DTCs, freeze frame
data, and a variety of the engine data. The DTCs and freeze frame data can be erased with the
Techstream. In order to enhance OBD function on vehicles and develop the Off-Board diagnosis system,
Controller Area Network (CAN) communication is used in this system. CAN is a network which uses a
pair of data transmission lines spanning multiple computers and sensors. It allows for high speed
communications between the systems and simplification of the wire harness connections.

Techstream only:

Since this system is equipped with CAN communication, connecting the CAN Vehicle Interface Module
(VIM) with the Techstream is necessary to display any information from the ECM. Also, communications
between the Techstream and ECM are performed through CAN communication signals. When
confirming DTCs and any data of the ECM, connect the CAN VIM between the DLC3 and Techstream.

2. NORMAL MODE AND CHECK MODE

The diagnosis system operates in normal mode during normal vehicle use. In normal mode, 2 trip
detection logic is used to ensure accurate detection of malfunctions. Check mode is also available as an
option for technicians. In check mode, 1 trip detection logic is used for simulating malfunction symptoms
and increasing the system's ability to detect malfunctions, including intermittent problems (Techstream
only).

3. TRIP DETECTION LOGIC

When a malfunction is first detected, the malfunction is temporarily stored in the ECM memory (1st trip).
If the same malfunction is detected during the next subsequent drive cycle, the MIL is illuminated (2nd
trip).

4. FREEZE FRAME DATA

The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is
stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was
running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich,

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

as well as other data recorded at the time of a malfunction.

5. BATTERY VOLTAGE

Standard voltage:

11 to 14 V

If voltage is below 11 V, replace or recharge the battery before proceeding.

6. MIL (Malfunction Indicator Lamp)

a. The MIL is illuminated when the ignition switch is first turned ON (the engine is not running).

b. The MIL should turn OFF when the engine is started. If the MIL remains illuminated, the diagnosis

system has detected a malfunction or abnormality in the system.

HINT:

If the MIL is not illuminated when the ignition switch is first turned ON, check the MIL circuit
(See MIL CIRCUIT ).

7. ALL READINESS

HINT:



With "ALL READINESS" you can check whether or not the DTC judgment has been completed by
using the Techstream.



You should check "ALL READINESS" after simulating malfunction symptoms or for validation
after finishing repairs.

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch ON.

c. Turn the Techstream ON.

d. Clear the DTCs.

e. Perform the DTC judgment driving pattern to run the DTC judgment.

f. Enter the following menus: Powertrain/Engine/Utility/All Readiness.

g. Input the DTCs to be confirmed.

h. Check the DTC judgment result.

DTC JUDGMENT CHART

Display Item

Description

NORMAL



DTC judgment completed



System normal

ABNORMAL



DTC judgment completed



System abnormal

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra