Toyota Sienna Service Manual: Diagnosis system
1. DESCRIPTION
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- When troubleshooting OBD II (On-Board
Diagnostics) vehicles, an intelligent tester
(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 onboard
computer illuminates the MIL (Malfunction
Indicator Lamp) on the instrument panel when the
computer detects a malfunction in:
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- The emission control systems and components
- The power train control components (which
affect vehicle emissions)
- The computer itself
In addition, the applicable DTCs (Diagnostic
Trouble Codes) prescribed by SAE J2012 are
recorded on 3 consecutive trips, the MIL turns
off automatically but the DTCs remain recorded
in the ECM memory.
- To check for DTCs, connect an 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.
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In order to enhance OBD function on vehicles and
develop the Off-Board diagnosis system, CAN
communication is introduced in this system (CAN:
Controller Area Network). It minimizes a gap
between technician skills and vehicle technology.
CAN is a network, which uses a pair of data
transmission lines, spanning multiple computers
and sensors. It allows a high speed communication
between the systems and to simplify the wire
harness connection.
Since this system is equipped with the CAN
communication, connecting the CAN VIM (VIM:
Vehicle Interface Module) with an intelligent tester is
necessary to display any information from the ECM.
(Also the communication between the intelligent
tester and the ECM uses CAN communication
signal.) When confirming the DTCs and any data of
the ECM, connect the CAN VIM between the DLC3
and the intelligent tester.
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 (intelligent tester only).
3. 2 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, as well as other data recorded at the
time of a malfunction.
5. DLC3 (Data Link Connector 3)
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- The vehicle's ECM uses ISO 15765-4 for
communication protocol. The terminal arrangement
of the DLC3 complies with SAE J1962 and matches
the ISO 15765-4 format.
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NOTICE:
*: Before measuring the resistance, leave the
vehicle as is for at least 1 minute and do not
operate the ignition switch, any other switches
or the doors.
HINT:
The DLC3 is the interface prepared for reading
various data from the vehicle's ECM. After
connecting the cable of an intelligent tester, turn the
ignition switch to the ON position and turn the tester
ON.
- If a communication failure message is displayed
on the tester screen (on the tester: UNABLE TO
CONNECT TO VEHICLE), a problem exists in
either the vehicle or tester. In order to identify the
location of the problem, connect the tester to
another vehicle.
- If communication is normal: Inspect the DLC3 on
the original vehicle.
- If communication is impossible: The problem is
probably in the tester itself. Consult the Service
Department listed in the instruction manual.
6. BATTERY VOLTAGE
Battery Voltage:
11 to 14 V
If the voltage is below 11 V, recharge the battery before
proceeding to the next step.
7. MIL (Malfunction Indicator Lamp)
- The MIL is illuminated when the ignition switch is
first turned to the ON position (the engine is not
running).
- 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 to the ON position, check the MIL
circuit
1. SFI SYSTEM
HINT:
The standard normal voltage between each pair of the
ECM terminals is shown in the table below. The
appropriate conditions for checking each pair of the
terminals are also i ...
NOTICE:
All the stored DTCs and freeze frame data are erased if:
the ECM is changed from normal mode to check mode
or vice versa; or 2) the ignition switch is turned from ON
to ACC or o ...
Other materials:
Installation
HINT:
Install the RH side by the same procedure as the LH side.
1. INSTALL FRONT DISC BRAKE CYLINDER SLIDE BUSH
(a) Apply the lithium soap base glycol grease to a new
front disc brake cylinder slide bush.
(b) Install the cylinder slide bush to the bottom side of
the front disc brake cyli ...
Rear Air Conditioning Control Panel Circuit
DESCRIPTION
This is the rear A/C system control signal circuit as well as the power
supply circuit of the rear A/C control
assembly.
Pulse signals regarding rear A/C control panel switch operation are transmitted
between the A/C amplifier
and rear A/C control assembly.
WIRING DIAGRAM
...
Open in Curtain Shield Squib LH Circuit
DTC B1166/88 Open in Curtain Shield Squib LH Circuit
DESCRIPTION
The curtain shield squib LH circuit consists of the center airbag sensor
assembly and the curtain shield
airbag assembly LH.
The circuit instructs the SRS to deploy when deployment conditions are met.
DTC B1166/88 is recorde ...