
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

Ok: unset (key is in ignition key cylinder) appears on the screen.

Ok: engine starts.


Ok: normal (transponder key coil is normal) appears on the screen.


Standard resistance 

Ok: engine starts normally.

End (transponder key amplifier is defective)
Unmatched key code
Communication malfunction no. 1Initializing the tire pressure
warning system (if
equipped)
â– The tire pressure warning
system must be initialized
in the following circumstances:
When rotating the tires.
When changing the tire.
After registering the ID codes.
When the tire pressure warning
system is initialized, the current
tire inflation pressure is set as
the benchmark pressure.
â ...
Terminals of ecu
Check tire pressure warning ecu
Disconnect the e56 ecu connector.
Measure the voltage and resistance of the wire
harness side connector.
If the result is not as specified, there may be a
malfunction on the wire harness side.
Reconnect the e56 ecu connector.
Measure the ...
Reassembly
Hint:
Thoroughly clean all parts to be assembled.
Before installing the parts, apply fresh engine oil to all
sliding and rotating surfaces.
Replace oil seals with new ones.
Install valve stem oil seal
Using sst, push in a new oil seal.
Sst 09201-41020
Hint:
The int ...