Rear Heater Control Panel LIN Communication Malfunction

NETWORKING: LIN COMMUNICATION SYSTEM: Rear Heater Control Panel LIN Communication Malfunction
- Rear Heater Control Panel LIN Communication Malfunction

DESCRIPTION

The LIN communication of the components related to the rear heater occurs between the air conditioning amplifier (A/C ECU) and rear air conditioning control panel.

HINT
"Rear heater control panel" refers to the rear air conditioning control panel.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
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 - REAR AIR CONDITIONING CONTROL PANEL)





(a) Disconnect the E36 amplifier connector.

(b) Disconnect the E55 panel connector.

(c) 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.

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 Removal.

(b) Check that the rear air conditioning function is normal.

OK:

Rear air conditioning function is normal.

NG -- REPLACE AIR CONDITIONING AMPLIFIER Removal

OK -- END (REAR AIR CONDITIONING CONTROL PANEL IS DEFECTIVE)