Heated Glass Element: Testing and Inspection

Rear Window Defogger Function Test

NOTE:

- Before troubleshooting the rear window defogger circuit, do multiplex integrated control system troubleshooting using B-CAN System Diagnosis Test Mode A Troubleshooting - B-CAN System Diagnosis Test Mode A.
- Be careful not to scratch or damage the defogger wires with the tester probe.
- Before testing, check the No. 30 (10 A) fuse in the under-dash fuse/relay box and the No. 10 (30 A) fuse in the rear 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.
- Faulty IG2 cut relay.
- Faulty rear MICU.
- Faulty climate control unit.
- An open or high resistance in the RED wire to the positive terminal.
- If there is battery 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 less than 0.2 V, go to step 3.
- If there is more than 0.2 V, check for:
- An open or high resistance in the wire.
- Poor ground (G 701).

3. Touch the voltmeter positive probe to each 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.
- 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.