Honda Accord: System Description
The vehicle is equipped with a Type Vll (GEN 5) immobilizer system that will disable the vehicle unless a programmed ignition key is used.
This system consists of a transponder combined with a keyless transmitter, an immobilizer-keyless control unit (Has built-in receiver), the driver's MICU (has built-in imoes unit), an immobilizer indicator, and the ECM/PCM.
When the immobilizer key (programmed by the HDS) is inserted into the ignition switch and turned to ON (II), the immobilizer-keyless control unit sends power to the transponder. The transponder then sends a coded signal back to the immobilizer-keyless control unit which then sends a coded signal to the ECM/PCM and the driver's MICU (imoes unit).
The ECM/PCM and driver's MICU (imoes unit) identify this coded signal, then voltage is supplied to the fuel pump.

If the wrong key has been used or the code was not received or recognized s, the indicator will flash once, then it will blink until the ignition switch is turned to LOCK (0). When the ignition switch is turned to the LOCK (0) position, the indicator will blink ten times to signal that unit has reset correctly, then the indicator will go off.
Circuit Diagram
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See also:
Test/Replacement
EX-L, EX-L PZEV models
1. Remove the cover (A), then disconnect BP connector
(B).
2. Turn the ignition switch to ON (II).
3. Measure the voltage between terminal No. 2 and
body ground.
вР...
Air Mix Control Motor Replacement
1. Remove the driver's dashboard undercover (see page
20-170).
2. Disconnect the 7P connector (A) from the air mix
control motor (B). Remove the self-tapping screws
and the air mix control motor ...
Audio Communication Line Circuit
Troubleshooting
1. Turn the ignition switch to LOCK (0).
2. Disconnect climate control unit connector A (28P) and
the audio-HVAC subdisplay (with navigation) or
audio-HVAC display unit (without navigation) 12P
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