Heated Glass Element: Testing and Inspection

Rear Window Defogger Function Test

Before troubleshooting the rear window defogger circuit, perform multiplex integrated control system troubleshooting using B-CAN System Diagnosis Test Mode A Troubleshooting - B-CAN System Diagnosis Test Mode A.

NOTE:

- Be careful not to scratch or damage the defogger wires with the tester probe.
- Before testing, check the No. 14 (30 A) fuse in the under-hood fuse/relay box and No. 30 (10 A) fuse in the driver's under-dash fuse/relay box.

1. Measure the voltage between the positive terminal (A) and body ground with the ignition switch and defogger switch ON.

There should be battery voltage.

- If there is no voltage, check for:
- Faulty rear window defogger relay Power Relay Test.
- Faulty MICU-rear junction box.
- Faulty climate (or heater) control panel.
- An open in the BLK/YEL wire to the positive terminal.
- If there is voltage, go to step 2.





2. Measure the voltage between the negative terminal (B) and body ground. There should be less than 0.2 V.

If there is greater than 0.2 V, check for an open or high resistance in the wire or poor ground (G701) or an open in the ground wire. If there is continuity, go to step 3.

3. Touch voltmeter positive probe to each specified point on each defogger wire, and the negative probe to the negative terminal.

- If the voltage is as specified, the defogger wire up to that point is OK.
- If the voltage is not as specified, repair the defogger wire Service and Repair.
- If it is more than specified at one of the points, there is a break in the negative half of the wire.
- If it is less than specified at one of the points, there is a break in the positive half of the wire.