Toyota RAV4 (XA40) 2013-2018 Service Manual: Communication
Description
When a key is inserted into the ignition key cylinder but no communication occurs between the key and transponder key ecu, dtc b2796 is output. When a key is inserted into the ignition key cylinder but a communication error occurs between the key and transponder key ecu, dtc b2798 is output.
Wiring diagram
Inspection procedure
- Read value of intelligent tester (engine immobiliser system)
- Connect the intelligent tester (with can vim) to the dlc3.
- Turn the ignition switch on with a key that cannot start the engine.
- On the intelligent tester, enter the following menus: diagnosis / obd/mobd / immobiliser / data list / immobiliser. Read the result.
Ok: unset (key is in ignition key cylinder) appears on the screen.
- Check whether engine starts with other key
- Check whether the engine starts with the vehicle's other keys.
Ok: engine starts.
- Read value of intelligent tester (transponder key coil)
- Connect the intelligent tester (with can vim) to the dlc3.
- Turn the ignition switch on with a key that cannot start the engine.
- On the intelligent tester, enter the following menus: diagnosis / obd/mobd / immobiliser / data list / antenna coil. Read the result.
Ok: normal (transponder key coil is normal) appears on the screen.
- Check wire harness (transponder key ecu - transponder key amplifier)
- Disconnect the e46 ecu connector.
- Disconnect the e5 amplifier connector.
- Measure the resistance of the wire harness side connectors.
Standard resistance 
- Check transponder key amplifier (operation)
- Temporarily replace the transponder key amplifier with a new or normally functioning one..
- Check that the engine starts normally
Ok: engine starts normally.
End (transponder key amplifier is defective)
Unmatched key code
Description
This dtc is output when a key code that has not been registered in the
transponder key ecu is inserted
into the ignition key cylinder.
Inspection procedure
Reregister key
...
Communication malfunction no. 1
Description
This dtc is output when a communication error occurs between the transponder
key amplifier and
transponder key ecu. Some possible reasons for the communication error are: 1) 2
or ...
Other materials:
Problem symptoms table
Hint:
Use the table below to help determine the cause of the
problem symptom. The potential causes of the symptoms
are listed in order of probability in the "suspected area"
column of the table. Check each symptom by checking the
suspected areas in the order they are listed. Re ...
Transmission fluid temperature sensor "A" circuit
Description
The automatic transmission fluid (atf) temperature sensor converts the atf
temperature into a
resistance value which is input into the ecm.
The ecm applies a voltage to the temperature sensor through ecm terminal tho1.
The sensor resistance changes with the atf temperature. ...
Diagnostic trouble code chart
Hint:
If no abnormality is found when inspecting parts, check the
skid control ecu and check for poor contact at the ground
points.
If a dtc is displayed during the dtc check, check the
circuit for the dtc listed in the table below. For details of
each dtc, refer to the page indicated. ...
