Circuit/System Testing
- Vehicle Power Mode - Off.
- Disconnect The X1 And X2 Harness Connectors At The E18 Rear Window Defogger Grid. It May Take Up To 2 Min For All Vehicle Systems To Power Down.
- Test For Less Than 10 Ω Between The E18 Rear Window Defogger Grid Ground Circuit Terminal 1 X2 And Ground.
- If 10 Ω Or Greater
- Test For Less Than 2 Ω In The Ground Circuit End To End.
- If 2 Ω Or Greater, Repair The Open/High Resistance In The Circuit.
- If Less Than 2 Ω, Repair The Open/High Resistance In The Ground Connection.
- Go To Next Step: If Less Than 10 Ω
- Connect A Test Lamp Between The Control Circuit Terminal 1 X1 And Ground.
- Vehicle Power Mode - Propulsion Mode/On.
- Verify The Test Lamp Does Not Turn On And Off When Pressing The Appropriate Switch On The A26 Heater And Air Conditioning User Interface Control - Front.
- If The Test Lamp Turns On And Off
Test Or Replace The E18 Rear Window Defogger Grid.
- Go To Next Step: If The Test Lamp Does Not Turn On And Off
- If The Test Lamp Turns On And Off
- Vehicle Power Mode - Off.
- Connect The X1 And X2 Harness Connectors At The E18 Rear Window Defogger Grid. Disconnect The X2 Harness Connector At The X50A Engine Wiring Harness Junction Block.
- Vehicle Power Mode - Propulsion Mode/On.
- Verify The E18 Rear Window Defogger Grid Is Not Activated.
- If The E18 Rear Window Defogger Grid Is Activated
- Vehicle Power Mode - Off.
- Disconnect The X1 Harness Connector At The E18 Rear Window Defogger Grid.
- Vehicle Power Mode - Propulsion Mode/On.
- Test For Less Than 1 V Between The E18 Rear Window Defogger Grid Control Circuit Terminal 1 And Ground.
- If 1 V Or Greater, Repair The Short To Voltage On The Circuit.
- If Less Than 1 V, Test Or Replace The E18 Rear Window Defogger Grid.
- Go To Next Step: If The E18 Rear Window Defogger Grid Is Not Activated
- Connect A 30 A Fused Jumper Wire Between The Control Circuit Terminal 44 X2 And B+.
- Verify The E18 Rear Window Defogger Grid Activates.
- If The E18 Rear Window Defogger Grid Does Not Activate
- Vehicle Power Mode - Off.
- Remove The Jumper Wire, Disconnect The X1 Harness Connector At The E18 Rear Window Defogger Grid.
- Test For Infinite Resistance Between The E18 Rear Window Defogger Grid Control Circuit Terminal 1 And Ground.
- If Less Than Infinite Resistance, Repair The Short To Ground On The Circuit.
- Go To Next Step: If Infinite Resistance
- Test For Less Than 2 Ω In The Control Circuit End To End.
- If 2 Ω Or Greater, Repair The Open/High Resistance In The Circuit.
- If Less Than 2 Ω, All Ok.
- Go To Next Step: If The E18 Rear Window Defogger Grid Activates
- Vehicle Power Mode - Off.
- Test For Less Than 10 Ω Between The X50A Engine Wiring Harness Junction Block Ground Circuit Terminal 32 X2 And Ground.
- If 10 Ω Or Greater
- Test For Less Than 2 Ω In The Ground Circuit End To End.
- If 2 Ω Or Greater, Repair The Open/High Resistance In The Circuit.
- If Less Than 2 Ω, Repair The Open/High Resistance In The Ground Connection.
- Go To Next Step: If Less Than 10 Ω
- Connect The X2 Harness Connector At The X50A Engine Wiring Harness Junction Block. Disconnect The X5 Harness Connector At The K9 Body Control Module.
- Vehicle Power Mode - Propulsion Mode/On.
- Verify The E18 Rear Window Defogger Grid Is Not Activated.
- If The E18 Rear Window Defogger Grid Is Activated
- Vehicle Power Mode - Off.
- Disconnect The X2 Harness Connector At The X50A Engine Wiring Harness Junction Block.
- Vehicle Power Mode - Propulsion Mode/On.
- Test For Less Than 1 V Between The K9 Body Control Module Circuit 193 And Ground.
- If 1 V Or Greater, Repair The Short To Voltage On The Circuit.
- If Less Than 1 V, Test Or Replace The X50A Engine Wiring Harness Junction Block.
- Go To Next Step: If The E18 Rear Window Defogger Grid Is Not Activated
- Connect A 3 A Fused Jumper Wire Between The Control Circuit Terminal 22 X5 And B+.
- Verify The E18 Rear Window Defogger Grid Activates.
- If The E18 Rear Window Defogger Grid Does Not Activate
- Vehicle Power Mode - Off.
- Remove The Jumper Wire, Disconnect The X2 Harness Connector At The X50A Engine Wiring Harness Junction Block.
- Test For Infinite Resistance Between The K9 Body Control Module Circuit 193 And Ground.
- If Less Than Infinite Resistance, Repair The Short To Ground On The Circuit.
- Go To Next Step: If Infinite Resistance
- Test For Less Than 2 Ω In The Control Circuit End To End.
- If 2 Ω Or Greater, Repair The Open/High Resistance In The Circuit.
- If Less Than 2 Ω, Replace The X50A Engine Wiring Harness Junction Block.
- Go To Next Step: If The E18 Rear Window Defogger Grid Activates
- Replace The K9 Body Control Module.