Toyota RAV4 (XA40) 2013-2018 Service Manual: 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 more ignition keys are positioned too close together, or 2) noise is occurring in the communication line.
Wiring diagram
Inspection procedure
- Check key
- Check if the ignition key being used is near other ignition keys. Also, check if the key ring is in contact with the key grip.
Result:
- Check for dtc
- Separate the keys from each other and / or remove the key ring.
- Clear the dtc (see page ei-18).
- Insert a key into the ignition key cylinder. Remove it.
Repeat for all other keys.
- Check that no dtc is output.
Ok: no dtc is output.
- Check transponder key ecu (noise)
- Using an oscilloscope or the intelligent tester, check for noise in the waveform between the terminals of the e5 amplifier connector and e46 ecu connector.
Ok:
no noise is present (see illustration).
- 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 replacing the transponder key amplifier with a new or normally functioning one.
- Check that the engine starts normally.
Ok: engine starts.
End (transponder key amplifier is defective)
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
ig ...
Engine immobiliser system malfunction
Description
This dtc is output when one of the following occurs: 1) the ecm detects
errors in its own
communications with the transponder key ecu; 2) the ecm detects errors in the
communicat ...
Other materials:
Propeller shaft system
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 th ...
Engine coolant temperature circuit
Description
A thermistor, whose resistance value varies according to the ect, is built
into the engine coolant
temperature (ect) sensor.
The structure of the sensor and its connection to the ecm are the same as those
of the intake air
temperature (iat) sensor.
Hint:
When any of dtcs ...
Disassembly
Caution:
Wear protective gloves. Sharp areas on the seat frame
(with adjuster) may injure your hands.
Hint:
Use the same procedures for the rh side and lh side.
The procedures listed below are for the lh side.
Remove vertical adjuster cover lh (for driver side)
Using a screw ...
