Toyota RAV4 (XA40) 2013-2018 Service Manual: Diagnosis system
- Description
- When troubleshooting on-board diagnostic (obd
ii) vehicles, the vehicle must be connected to the
obd ii scan tool (complying with sae j1987).
Various data output from the vehicle's ecm can
then be read.
- Obd ii regulations require that the vehicle's onboard
computer illuminates the malfunction
indicator lamp (mil) on the instrument panel when
the computer detects a malfunction in:
- The emission control system/components
- The powertrain control components (which affect
vehicle emissions)
- The computer
In addition, the applicable diagnostic trouble
codes (dtcs) prescribed by sae j2012 are
recorded in the ecm memory.
When the malfunction does not reoccur, the mil
stays illuminated until the ignition switch is
turned off, and the mil turns off when the
engine is started. However, the dtcs remain
recorded in the ecm memory.
- To check dtcs, connect the intelligent tester to the
data link connector 3 (dlc3) of the vehicle. The
tester displays dtcs, the freeze frame data and a
variety of the engine data.
The dtcs and freeze frame data can be erased
with the tester (see page ax-29).
- 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 to
technicians as an option. In check mode, "1 trip
detection logic" is used for simulating malfunction
symptoms and increasing the system's ability to
detect malfunctions, including intermittent
malfunctions.
- 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 drive cycle, the mil is
illuminated (2nd trip).
- Freeze frame data
- Freeze frame data records the engine conditions
(fuel system, calculated load, engine coolant
temperature, fuel trim, engine speed, vehicle speed,
etc.) When a malfunction is detected. When
troubleshooting, freeze frame data can help
determine if the vehicle was running or stopped, 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.
- The intelligent tester records freeze frame data in 5
different instances: 1) 3 times before the dtc is set,
2) once when the dtc is set, and 3) once after the
dtc is set. These data can be used to simulate the
vehicle's condition around the time when the
malfunction occurred. The data may help find the
cause of the malfunction, or judge if the dtc is
being caused by a temporary malfunction or not.
- Data link connector 3 (dlc3)
- The vehicle's ecm uses the iso 15765-4 for
communication protocol. The terminal arrangement
of the dlc3 complies with sae j1962 and matches
the iso 15765-4 format.
Hint:
*: Before measuring the resistance, leave the vehicle as is for
at least 1 minute and do not operate the ignition switch, other
switches or doors.
If the result is not as specified, the dlc3 may have a
malfunction. Repair or replace the harness and connector.
Hint:
Connect the cable of the intelligent tester to the dlc3, turn
the ignition switch on and attempt to use the tester. If the
screen displays unable to connect to vehicle, a
problem exists in the vehicle side or the tester side.
If communication is normal when the tester is connected to
another vehicle, inspect the dlc3 on the original vehicle.
If communication is still not possible when the tester is
connected to another vehicle, the problem is probably in the
tester itself. Consult the service department listed in the
tester's instruction manual.
- Check mil
- Check that the mil illuminates when turning the
ignition switch on.
If the mil does not illuminate, there is a problem in
the mil circuit (see page es-386).
- When the engine is started, the mil should turn off.
- All readiness
- For this vehicle, using the intelligent tester allows
readiness codes corresponding to all dtcs to be
read. When the diagnosis (normal or
malfunctioning) has been completed, readiness
codes are set. Enter the following menus:
enhanced obd ii / monitor status.
Check ecm
Measure the voltage of the ecm connector.
Hint:
Each ecm terminal's standard voltage is shown in
the table below.
In the table, first follow the information under
" ...
Check dtc
Dtcs which are stored in the ecm can be displayed
with the intelligent tester.
The intelligent tester can display pending dtcs and
current dtcs. Some dtcs are not stored ...
Other materials:
Low battery positive voltage
Description
When there is an abnormality in the power supply circuit of the brake
actuator (skid control ecu), the skid
control ecu sets a dtc and the operation is prohibited by the fail-safe
function. This dtc is set when the
voltage supplied to terminal ig1 is outside the dtc detection ...
Downhill assist control indicator light does not come on
Description
Refer to the description of "downhill assist control indicator light remains
on" (see page bc-156).
Wiring diagram
Refer to the downhill assist control indicator light circuit (see page
bc-157).
Inspection procedure
Check can communication system
Check if the ...
Door courtesy switch circuit
Description
The main body ecu detects the condition of the door courtesy switch.
Wiring diagram
Inspection procedure
Read value of intelligent tester (door courtesy light switch)
Connect the intelligent tester (with can vim) to the
dlc3.
Turn the ignition switch to the on positi ...