LIN Communication System

NETWORKING: LIN COMMUNICATION SYSTEM: LIN Communication Circuit

LIN Communication Circuit

DESCRIPTION

The LIN communication of the components related to the rear heater occurs between the air conditioning amplifier (A/C ECU), rear air conditioning control panel and front air conditioning control panel*.
HINT: *: w/o Navigation System

WIRING DIAGRAM





INSPECTION PROCEDURE
NOTE: When using the Techstream with the engine switch off to troubleshoot:

Connect the Techstream to the vehicle, and turn a courtesy switch on and off at 1.5 second intervals until communication between the Techstream and vehicle begins.

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - AIR CONDITIONING CONTROL PANEL)





(a) Disconnect the E36 amplifier connector.
(b) Disconnect the E55 and F10* panel connectors.
(c) Measure the resistance and voltage according to the value(s) in the tables below.
HINT: *: w/o Navigation System

Standard Resistance:






Standard Voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
2. CHECK REAR AIR CONDITIONING CONTROL PANEL (BATTERY VOLTAGE AND BODY GROUND)





(a) Disconnect the E55 panel connector.
(b) Measure the resistance and voltage according to the value(s) in the tables below.
Standard Resistance:






Standard Voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK REAR AIR CONDITIONING CONTROL PANEL
(a) Temporarily replace the rear air conditioning control panel with a new or normally functioning one.
(b) Check that the rear air conditioning function is normal.
OK:
Rear air conditioning function is normal.

Result





C -- REPLACE AIR CONDITIONING AMPLIFIER
B -- CHECK FRONT AIR CONDITIONING CONTROL PANEL (BATTERY VOLTAGE AND BODY GROUND)
A -- END (REAR AIR CONDITIONING CONTROL PANEL IS DEFECTIVE)
4. CHECK FRONT AIR CONDITIONING CONTROL PANEL (BATTERY VOLTAGE AND BODY GROUND)





(a) Disconnect the F10 panel connector.
(b) Measure the resistance and voltage according to the value(s) in the table below.
Standard Resistance:






Standard Voltage:






NG -- REPLACE FRONT AIR CONDITIONING CONTROL PANEL
OK -- Continue to next step.
5. CHECK FRONT AIR CONDITIONING CONTROL PANEL
(a) Temporarily replace the front air conditioning control panel with a new or normally functioning one.
(b) Check that the front air conditioning function is normal.
OK:
Front air conditioning function is normal.
NG -- REPLACE AIR CONDITIONING AMPLIFIER
OK -- END (FRONT AIR CONDITIONING CONTROL PANEL IS DEFECTIVE)