Communication Diagnosis Procedure

Check the communication between BCM and each local control unit (LCU).

Operation Procedure:

Operation procedure

Diagnosis result display
- The indicator lamps (the map lamp and step lamp) turn ON (illuminate) for 2 seconds and OFF (go off) for 2 seconds to indicate that the diagnosis has started, then indicate the diagnosis trouble code.
- To indicate the diagnosis trouble code, the indicator lamps illuminate or flash.
- At first, the lamps indicate the second place by ON/OFF with 0.5 second interval, then OFF for 1.5 seconds. Next, they indicate the first place by ON/OFF with 0.5 second interval.
- If there are multiple malfunctioning parts, the lamps indicate them in sequence from the smallest diagnosis trouble code.
- The diagnosis results repeat until the diagnosis is cancelled.
- If a malfunction is indicated, carry out the communication diagnosis again to check that the same diagnosis trouble code is indicated.

Diagnosis Trouble Code Indication Example:

Diagnosis trouble code indication example

Trouble Diagnosis Chart:

Trouble diagnosis chart

NOTE:
- For a specific local control unit (LCU), either "PAST COMM DATA" or "PAST NO RESPONSE" may be displayed instead of the above results. This is caused by the data record, so erase the records.
(The display only shows the incident records, they are not malfunctions caused during the diagnosis. One possible cause is that an irreproducible incident occurred.)
- Follow the steps below to erase the memory.
Carry out either disconnect BCM battery power supply or erase memory with CONSULT-II.
- With the battery connected, if the local control unit (LCU) connector is disconnected and left for approximately 1 minute, the BCM stores "NO RESPONSE" record.

Cancel of communication diagnosis
If the following conditions are satisfied, the communication diagnosis is cancelled.
- When the ignition switch is turned OFF.
- The vehicle speed becomes 7 km/h (4MPH) or higher.
- Ten minutes have passed since the diagnosis result indication start without no diagnosis cancel operation.

Communication System A Step 1 - 2:

COMMUNICATION SYSTEM A

Communication System B Step 1 - 2:

COMMUNICATION SYSTEM B

Communication System C Step 1 - 2:

COMMUNICATION SYSTEM C