Window Defogger Does Not Operate

Window Defogger Does Not Operate

Description of functions

When IG is ON, operating the rear window defogger switch turns on the rear window defogger.

Except for automatic air conditioning system
Rear window defogger control is performed by the main body ECM (network gateway computer). When the switch ON signal is received, RR DEF relay operates for 15 minutes. When the switch OFF signal is received within 15 minutes, operation of DEFOG relay stops.

For automatic air conditioning system
Rear window defogger control is performed by the main body ECM (network gateway computer). When the switch ON signal is transmitted from the air conditioner control ASSY through the CAN communication to the main body ECM (network gateway computer), RR DEF relay operates for 15 minutes. When the switch OFF signal is received within 15 minutes, operation of RR DEF relay stops.

Circuit figure










Inspection steps

WARNING:
- Window defogger system uses CAN communication. First, follow the "How to troubleshoot" and perform the "Communication function inspection" to check that malfunction does not occur in the communication system, and then proceed to the troubleshooting.
- Before performing the troubleshooting, check the fuse of this circuit.