Function Test

NOTE:

Before testing, perform multiplex integrated control system troubleshooting using B-CAN System Diagnosis Test Mode A (see DEFOGGER WIRE REPAIR ).
Before testing, check the No. 14(40 A) and No. 2 (30 A) fuses in the under-hood fuse/relay box and the No. 30 (7.5 A) fuse in the driver's under-dash fuse/ relay box.
Be careful not to scratch or damage the defogger wires with the tester probe.

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 antenna module.
  - Faulty climate control unit assembly.
  - Faulty noise condenser
  - An open in the BLU wire to the positive terminal.
- If there is voltage, go to step 2.
Fig 1: Measuring Voltage Between Positive Terminal And Body Ground With Ignition Switch And Defogger Switch
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Disconnect the negative terminal (B) from the rear window defogger.
Check for continuity between the negative terminal and body ground.
If there is no continuity, check for an open in the wire or poor ground (G851). If there is continuity, go to step 4.
Reconnect the negative terminal to the rear window defogger.
Turn the ignition switch to ON (II) and the rear window defogger switch ON.
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.