Toyota Sienna Service Manual: Diagnosis system
1. DESCRIPTION
- 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:
- 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.
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)
- 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.
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:
On-vehicle inspection
1. INSPECT COOLING FAN SYSTEM
(a) Put the vehicle in the following conditions
(1) The engine switch is off.
(2) The coolant temperature is less than 95°C
(203°F).
(3) The battery voltage is between 9 and 14 V.
(4) The A/C switch is OFF.
(b) Clamp the 400 A probe of an ammeter over the ...
Open in ABS Solenoid Relay Circuit
DESCRIPTION
This relay supplies power to each ABS solenoid.
Immediately after the ignition switch is turned to the ON position, the relay
turns on if the solenoid is
determined to be normal as a result of self-diagnosis during initial check.
The relay turns off if an open/short is dete ...
No Answer-Back (Hazard Warning Light and Wireless Door Lock
Buzzer)
DESCRIPTION
If there is no answer-back of the hazard light signal and the wireless door lock
buzzer although the
wireless control function is operating normally, there might be a malfunction in
the hazard light signal and
the wireless door lock buzzer signal which are output from the multiple ...